There may be circumstances where it's desirable that all blocks
in a specified dataset be stored on the special device. Relax
the artificial 128K limit and allow the special_small_blocks
property to be set up to 1M. When blocks >1MB have been enabled
via the zfs_max_recordsize module option, this limit is increased
accordingly.
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9131Closes#9355
As described in commit f81d5ef6 the zfs_vdev_elevator module
option is being removed. Users who require this functionality
should update their systems to set the disk scheduler using a
udev rule.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #8664Closes#9417Closes#9609
The function zdb_read_block (zdb -R) was always intended to have a :c
flag which would read the DVA and length supplied by the user, and
display the checksum. Since we don't know which checksum goes with
the data, we should calculate and display them all.
For each checksum in the table, read in the data at the supplied
DVA:length, calculate the checksum, and display it. Update the man
page and create a zfs test for the new feature.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Signed-off-by: Paul Zuchowski <pzuchowski@datto.com>
Closes#9607
zed.service does not exist
replaced with correct service name in man.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Kjeld Schouten-Lebbing <kjeld@schouten-lebbing.nl>
Closes#9581
Moved subcommand topics into individual manpages. Reordered and
grouped the list of subcommands by topic.
Moved concepts overview to `zpoolconcepts.8` and the long list of
available pool properties to `zpoolprops.8`.
Internal cross-references copied from `zpool.8` needed to be
converted to `.Xr` external references to new subcommand manual
pages.
Move `autotrim` into lexical order, autotrim tacked onto the end
of a list. Now it is in alphabetical order.
Clarify attach/detach description. Description was too specific to
command syntax. Overview clarifies reason for attaching or detaching
a device.
Clarify replace description, don't refer to subcommand arguments.
Clarify split command description, say what split actually does and
why you'd want to do it.
Clarify description of upgrade, and simplify the zpool.8 wording of
the zpool-upgrade(8) description.
Clarify description of import, detail what zpool-import(8) actually
does.
Add appropriate SEE ALSO sections. Divided zpool subcommand manual
pages need their own SEE ALSO sections. Also modified fsck.zfs.8
to point directly to zfs-scrub.8 and zed.8.in to include a direct
reference to zfs-events.8
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ross Williams <ross@ross-williams.net>
Closes#9564
Most subcommands got their own manpages (e.g. create). Some related
commands grouped into a single manpage and symlinks created (e.g. set,
get, and inherit). I did this when topics were either too short to
warrant their own file or so interrelated that a user would want to
refer between commands in the same file.
Corrected .Sx internal references to .Xr cross refs; lots of .Sx
references from when text was all in zfs.8 needed to be changed to
.Xr zfs-$SUBCOMMAND 8 cross references.
Divided subcommand list in zfs(8) into sections of related
functionality. This required writing new descriptions for some
commands.
Preserved ".Os Linux", `.Os` macro parsing behavior differs between
mandoc from the "BSD" mandoc package (available on Ubuntu) and man
from Ubuntu's man-db package, which calls groff to format the manpages.
Groff handles the `.Os` macro differently and wrongly, defaulting
it to "BSD" in `/usr/share/groff/*/tmac/mdoc/doc-common`, instead of
getting the default from `uname`.
A future set of changes will introduce build-time preprocessing of
manpages for platform-specific documentation and can insert the
correct operating system name.
Added SEE ALSO sections, the newly-divided zfs-*.8 subcommand man
pages needed their own SEE ALSO sections pointing to related
subcommands and, in some cases, documentation from other packages
(e.g. zfs-share.8).
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ross Williams <ross@ross-williams.net>
Closes#9559
It is much faster than AVX512F when byteswapping on Skylake-SP
and newer, as we can do the byteswap in a single vshufb instead
of many instructions.
Reviewed by: Gvozden Neskovic <neskovic@gmail.com>
Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Romain Dolbeau <romain.dolbeau@atos.net>
Closes#9517
While it may sometimes be convenient to export an NFS filesystem with
no_root_squash it should not be the default behavior. Align the
default behavior with the Linux NFS server defaults. To restore
the previous behavior use 'zfs set sharenfs="no_root_squash,..."'.
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9397Closes#9425
Since 0.7.0, zpool import would unconditionally block on udev for 30
seconds. This introduced a regression in initramfs environments that
lack udev (particularly mdev based environments), yet use a zfs userland
tools intended for the system that had been built against udev. Gentoo's
genkernel is the main example, although custom user initramfs
environments would be similarly impacted unless special builds of the
ZFS userland utilities were done for them. Such environments already
have their own mechanisms for blocking until device nodes are ready
(such as genkernel's scandelay parameter), so it is unnecessary for
zpool import to block on a non-existent udev until a timeout is reached
inside of them.
Rather than trying to intelligently determine whether udev is available
on the system to avoid unnecessarily blocking in such environments, it
seems best to just allow the environment to override the timeout. I
propose that we add an environment variable called
ZPOOL_IMPORT_UDEV_TIMEOUT_MS. Setting it to 0 would restore the 0.6.x
behavior that was more desirable in mdev based initramfs environments.
This allows the system user land utilities to be reused when building
mdev-based initramfs archives.
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Georgy Yakovlev <gyakovlev@gentoo.org>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#9436
Update the zfs(8) man page to clearly describe that arguments for
channel programs are to be listed after the -- sentinel which
terminates argument processing. This behavior is supported by
getopt on Linux, FreeBSD, and Illumos according to each platforms
respective man pages.
zfs program [-jn] [-t instruction-limit] [-m memory-limit]
pool script [--] arg1 ...
Reviewed-by: Clint Armstrong <clint@clintarmstrong.net>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9056Closes#9428
Originally the zfs_vdev_elevator module option was added as a
convenience so the requested elevator would be automatically set
on the underlying block devices. At the time this was simple
because the kernel provided an API function which did exactly this.
This API was then removed in the Linux 4.12 kernel which prompted
us to add compatibly code to set the elevator via a usermodehelper.
While well intentioned this introduced a bug which could cause a
system hang, that issue was subsequently fixed by commit 2a0d4188.
In order to avoid future bugs in this area, and to simplify the code,
this functionality is being deprecated. A console warning has been
added to notify any existing consumers and the documentation updated
accordingly. This option will remain for the lifetime of the 0.8.x
series for compatibility but if planned to be phased out of master.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #8664Closes#9317
Currently the best way to wait for the completion of a long-running
operation in a pool, like a scrub or device removal, is to poll 'zpool
status' and parse its output, which is neither efficient nor convenient.
This change adds a 'wait' subcommand to the zpool command. When invoked,
'zpool wait' will block until a specified type of background activity
completes. Currently, this subcommand can wait for any of the following:
- Scrubs or resilvers to complete
- Devices to initialized
- Devices to be replaced
- Devices to be removed
- Checkpoints to be discarded
- Background freeing to complete
For example, a scrub that is in progress could be waited for by running
zpool wait -t scrub <pool>
This also adds a -w flag to the attach, checkpoint, initialize, replace,
remove, and scrub subcommands. When used, this flag makes the operations
kicked off by these subcommands synchronous instead of asynchronous.
This functionality is implemented using a new ioctl. The type of
activity to wait for is provided as input to the ioctl, and the ioctl
blocks until all activity of that type has completed. An ioctl was used
over other methods of kernel-userspace communiction primarily for the
sake of portability.
Porting Notes:
This is ported from Delphix OS change DLPX-44432. The following changes
were made while porting:
- Added ZoL-style ioctl input declaration.
- Reorganized error handling in zpool_initialize in libzfs to integrate
better with changes made for TRIM support.
- Fixed check for whether a checkpoint discard is in progress.
Previously it also waited if the pool had a checkpoint, instead of
just if a checkpoint was being discarded.
- Exposed zfs_initialize_chunk_size as a ZoL-style tunable.
- Updated more existing tests to make use of new 'zpool wait'
functionality, tests that don't exist in Delphix OS.
- Used existing ZoL tunable zfs_scan_suspend_progress, together with
zinject, in place of a new tunable zfs_scan_max_blks_per_txg.
- Added support for a non-integral interval argument to zpool wait.
Future work:
ZoL has support for trimming devices, which Delphix OS does not. In the
future, 'zpool wait' could be extended to add the ability to wait for
trim operations to complete.
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: John Gallagher <john.gallagher@delphix.com>
Closes#9162
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes#9233
With the other metaslab changes loaded onto a system, we can
significantly reduce the memory usage of each loaded metaslab and
unload them on demand if there is memory pressure. However, none
of those changes actually result in us keeping more metaslabs loaded.
If we don't keep more metaslabs loaded, we will still have to wait
for demand-loading to finish when no loaded metaslab can satisfy our
allocation, which can cause ZIL performance issues. In addition,
performance is traditionally measured by IOs per unit time, while
unloading is currently done on a txg-count basis. Txgs can take a
widely varying range of times, from tenths of a second to several
seconds. This can result in confusing, hard to predict behavior.
This change simply adds a time-based component to metaslab unloading.
A metaslab will remain loaded for one minute and 8 txgs (by default)
after it was last used, unless it is evicted due to memory pressure.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
External-issue: DLPX-65016
External-issue: DLPX-65047
Closes#9197
On systems with large amounts of storage and high fragmentation, a huge
amount of space can be used by storing metaslab range trees. Since
metaslabs are only unloaded during a txg sync, and only if they have
been inactive for 8 txgs, it is possible to get into a state where all
of the system's memory is consumed by range trees and metaslabs, and
txgs cannot sync. While ZFS knows how to evict ARC data when needed,
it has no such mechanism for range tree data. This can result in boot
hangs for some system configurations.
First, we add the ability to unload metaslabs outside of syncing
context. Second, we store a multilist of all loaded metaslabs, sorted
by their selection txg, so we can quickly identify the oldest
metaslabs. We use a multilist to reduce lock contention during heavy
write workloads. Finally, we add logic that will unload a metaslab
when we're loading a new metaslab, if we're using more than a certain
fraction of the available memory on range trees.
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#9128
When a pool is imported it will scan the pool to verify the integrity
of the data and metadata. The amount it scans will depend on the
import flags provided. On systems with small amounts of memory or
when importing a pool from the crash kernel, it's possible for
spa_load_verify to issue too many I/Os that it consumes all the memory
of the system resulting in an OOM message or a hang.
To prevent this, we limit the amount of memory that the initial pool
scan can consume. This change will, by default, use 1/16th of the ARC
for scan I/Os to prevent running the system out of memory during import.
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: George Wilson george.wilson@delphix.com
External-issue: DLPX-65237
External-issue: DLPX-65238
Closes#9146
Consumers of ZFS Channel Programs can now list bookmarks,
and get holds from datasets. A minor-refactoring was also
applied to distinguish between user and system properties
in ZCP.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Ported-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Dan Kimmel <dan.kimmel@delphix.com>
OpenZFS-issue: https://illumos.org/issues/8862Closes#7902
When we unload metaslabs today in ZFS, the cached max_size value is
discarded. We instead use the histogram to determine whether or not we
think we can satisfy an allocation from the metaslab. This can result in
situations where, if we're doing I/Os of a size not aligned to a
histogram bucket, a metaslab is loaded even though it cannot satisfy the
allocation we think it can. For example, a metaslab with 16 entries in
the 16k-32k bucket may have entirely 16kB entries. If we try to allocate
a 24kB buffer, we will load that metaslab because we think it should be
able to handle the allocation. Doing so is expensive in CPU time, disk
reads, and average IO latency. This is exacerbated if the write being
attempted is a sync write.
This change makes ZFS cache the max_size after the metaslab is
unloaded. If we ever get a free (or a coalesced group of frees) larger
than the max_size, we will update it. Otherwise, we leave it as is. When
attempting to allocate, we use the max_size as a lower bound, and
respect it unless we are in try_hard. However, we do age the max_size
out at some point, since we expect the actual max_size to increase as we
do more frees. A more sophisticated algorithm here might be helpful, but
this works reasonably well.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#9055
Update zpool-features.5 manpage to describe the log_spacemap feature.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#9096
Deleting a clone requires finding blocks are clone-only, not shared
with the snapshot. This was done by traversing the entire block tree
which results in a large performance penalty for sparsely
written clones.
This is new method keeps track of clone blocks when they are
modified in a "Livelist" so that, when it’s time to delete,
the clone-specific blocks are already at hand.
We see performance improvements because now deletion work is
proportional to the number of clone-modified blocks, not the size
of the original dataset.
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Sara Hartse <sara.hartse@delphix.com>
Closes#8416
The zfs-volume-wait.service scans existing zvols and waits for their
links under /dev to be created. Any service that depends on zvol
links to be there should add a dependency on zfs-volumes.target.
By default, this target is not enabled.
Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Reviewed-by: Antonio Russo <antonio.e.russo@gmail.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: John Gallagher <john.gallagher@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Zakharov <pzakharov@delphix.com>
Closes#8975
Adds the ability to sanity check zfs create arguments and to see the
value of any additional properties that will local to the dataset. For
example, automation that may need to adjust quota on a parent filesystem
before creating a volume may call `zfs create -nP -V <size> <volume>` to
obtain the value of refreservation. This adds the following options to
zfs create:
- -n dry-run (no-op)
- -v verbose
- -P parseable (implies verbose)
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Jerry Jelinek <jerry.jelinek@joyent.com>
Signed-off-by: Mike Gerdts <mike.gerdts@joyent.com>
Closes#8974
= Motivation
At Delphix we've seen a lot of customer systems where fragmentation
is over 75% and random writes take a performance hit because a lot
of time is spend on I/Os that update on-disk space accounting metadata.
Specifically, we seen cases where 20% to 40% of sync time is spend
after sync pass 1 and ~30% of the I/Os on the system is spent updating
spacemaps.
The problem is that these pools have existed long enough that we've
touched almost every metaslab at least once, and random writes
scatter frees across all metaslabs every TXG, thus appending to
their spacemaps and resulting in many I/Os. To give an example,
assuming that every VDEV has 200 metaslabs and our writes fit within
a single spacemap block (generally 4K) we have 200 I/Os. Then if we
assume 2 levels of indirection, we need 400 additional I/Os and
since we are talking about metadata for which we keep 2 extra copies
for redundancy we need to triple that number, leading to a total of
1800 I/Os per VDEV every TXG.
We could try and decrease the number of metaslabs so we have less
I/Os per TXG but then each metaslab would cover a wider range on
disk and thus would take more time to be loaded in memory from disk.
In addition, after it's loaded, it's range tree would consume more
memory.
Another idea would be to just increase the spacemap block size
which would allow us to fit more entries within an I/O block
resulting in fewer I/Os per metaslab and a speedup in loading time.
The problem is still that we don't deal with the number of I/Os
going up as the number of metaslabs is increasing and the fact
is that we generally write a lot to a few metaslabs and a little
to the rest of them. Thus, just increasing the block size would
actually waste bandwidth because we won't be utilizing our bigger
block size.
= About this patch
This patch introduces the Log Spacemap project which provides the
solution to the above problem while taking into account all the
aforementioned tradeoffs. The details on how it achieves that can
be found in the references sections below and in the code (see
Big Theory Statement in spa_log_spacemap.c).
Even though the change is fairly constraint within the metaslab
and lower-level SPA codepaths, there is a side-change that is
user-facing. The change is that VDEV IDs from VDEV holes will no
longer be reused. To give some background and reasoning for this,
when a log device is removed and its VDEV structure was replaced
with a hole (or was compacted; if at the end of the vdev array),
its vdev_id could be reused by devices added after that. Now
with the pool-wide space maps recording the vdev ID, this behavior
can cause problems (e.g. is this entry referring to a segment in
the new vdev or the removed log?). Thus, to simplify things the
ID reuse behavior is gone and now vdev IDs for top-level vdevs
are truly unique within a pool.
= Testing
The illumos implementation of this feature has been used internally
for a year and has been in production for ~6 months. For this patch
specifically there don't seem to be any regressions introduced to
ZTS and I have been running zloop for a week without any related
problems.
= Performance Analysis (Linux Specific)
All performance results and analysis for illumos can be found in
the links of the references. Redoing the same experiments in Linux
gave similar results. Below are the specifics of the Linux run.
After the pool reached stable state the percentage of the time
spent in pass 1 per TXG was 64% on average for the stock bits
while the log spacemap bits stayed at 95% during the experiment
(graph: sdimitro.github.io/img/linux-lsm/PercOfSyncInPassOne.png).
Sync times per TXG were 37.6 seconds on average for the stock
bits and 22.7 seconds for the log spacemap bits (related graph:
sdimitro.github.io/img/linux-lsm/SyncTimePerTXG.png). As a result
the log spacemap bits were able to push more TXGs, which is also
the reason why all graphs quantified per TXG have more entries for
the log spacemap bits.
Another interesting aspect in terms of txg syncs is that the stock
bits had 22% of their TXGs reach sync pass 7, 55% reach sync pass 8,
and 20% reach 9. The log space map bits reached sync pass 4 in 79%
of their TXGs, sync pass 7 in 19%, and sync pass 8 at 1%. This
emphasizes the fact that not only we spend less time on metadata
but we also iterate less times to convergence in spa_sync() dirtying
objects.
[related graphs:
stock- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGStock.png
lsm- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGLSM.png]
Finally, the improvement in IOPs that the userland gains from the
change is approximately 40%. There is a consistent win in IOPS as
you can see from the graphs below but the absolute amount of
improvement that the log spacemap gives varies within each minute
interval.
sdimitro.github.io/img/linux-lsm/StockVsLog3Days.png
sdimitro.github.io/img/linux-lsm/StockVsLog10Hours.png
= Porting to Other Platforms
For people that want to port this commit to other platforms below
is a list of ZoL commits that this patch depends on:
Make zdb results for checkpoint tests consistent
db587941c5
Update vdev_is_spacemap_addressable() for new spacemap encoding
419ba59145
Simplify spa_sync by breaking it up to smaller functions
8dc2197b7b
Factor metaslab_load_wait() in metaslab_load()
b194fab0fb
Rename range_tree_verify to range_tree_verify_not_present
df72b8bebe
Change target size of metaslabs from 256GB to 16GB
c853f382db
zdb -L should skip leak detection altogether
21e7cf5da8
vs_alloc can underflow in L2ARC vdevs
7558997d2f
Simplify log vdev removal code
6c926f426a
Get rid of space_map_update() for ms_synced_length
425d3237ee
Introduce auxiliary metaslab histograms
928e8ad47d
Error path in metaslab_load_impl() forgets to drop ms_sync_lock
8eef997679
= References
Background, Motivation, and Internals of the Feature
- OpenZFS 2017 Presentation:
youtu.be/jj2IxRkl5bQ
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemaps-project
Flushing Algorithm Internals & Performance Results
(Illumos Specific)
- Blogpost:
sdimitro.github.io/post/zfs-lsm-flushing/
- OpenZFS 2018 Presentation:
youtu.be/x6D2dHRjkxw
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemap-flushing-algorithm
Upstream Delphix Issues:
DLPX-51539, DLPX-59659, DLPX-57783, DLPX-61438, DLPX-41227, DLPX-59320
DLPX-63385
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8442
Modify zfs-mount-generator to produce a dependency on new
zfs-import-key-*.service units, dynamically created at boot to call
zfs load-key for the encryption root, before attempting to mount any
encrypted datasets.
These units are created by zfs-mount-generator, and RequiresMountsFor on
the keyfile, if present, or call systemd-ask-password if a passphrase is
requested.
This patch includes suggestions from @Fabian-Gruenbichler, @ryanjaeb and
@rlaager, as well an adaptation of @rlaager's script to retry on
incorrect password entry.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Antonio Russo <antonio.e.russo@gmail.com>
Closes#8750Closes#8848
* zfs redact error messages do not end with newline character
* 30af21b0 inadvertently removed some ZFS_PROP comments
* man/zfs: zfs redact <redaction_snapshot> is not optional
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#8988
The full property name includes "delphix", not "delphxi".
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8985
This was accidentally introduced in 765d1f06:
mandoc: ./man/man8/zfs.8: ERROR: skipping item outside list: It Ar filesystem Ns | Ns Ar mountpoint
mandoc: ./man/man8/zfs.8: ERROR: skipping item outside list: It Xo
mandoc: ./man/man8/zfs.8: ERROR: skipping end of block that is not open: Xc
mandoc: ./man/man8/zfs.8: ERROR: skipping item outside list: It Xo
mandoc: ./man/man8/zfs.8: ERROR: skipping end of block that is not open: Xc
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#8980
This patch adds the ability for the user to unload keys for
datasets as they are being unmounted. This is analogous to
'zfs mount -l'.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes: #8917Closes: #8952
If dedup is in use, the `dedupditto` property can be set, causing ZFS to
keep an extra copy of data that is referenced many times (>100x). The
idea was that this data is more important than other data and thus we
want to be really sure that it is not lost if the disk experiences a
small amount of random corruption.
ZFS (and system administrators) rely on the pool-level redundancy to
protect their data (e.g. mirroring or RAIDZ). Since the user/sysadmin
doesn't have control over what data will be offered extra redundancy by
dedupditto, this extra redundancy is not very useful. The bulk of the
data is still vulnerable to loss based on the pool-level redundancy.
For example, if particle strikes corrupt 0.1% of blocks, you will either
be saved by mirror/raidz, or you will be sad. This is true even if
dedupditto saved another 0.01% of blocks from being corrupted.
Therefore, the dedupditto functionality is rarely enabled (i.e. the
property is rarely set), and it fulfills its promise of increased
redundancy even more rarely.
Additionally, this feature does not work as advertised (on existing
releases), because scrub/resilver did not repair the extra (dedupditto)
copy (see https://github.com/zfsonlinux/zfs/pull/8270).
In summary, this seldom-used feature doesn't work, and even if it did it
wouldn't provide useful data protection. It has a non-trivial
maintenance burden (again see https://github.com/zfsonlinux/zfs/pull/8270).
We should remove the dedupditto functionality. For backwards
compatibility with the existing CLI, "zpool set dedupditto" will still
"succeed" (exit code zero), but won't have any effect. For backwards
compatibility with existing pools that had dedupditto enabled at some
point, the code will still be able to understand dedupditto blocks and
free them when appropriate. However, ZFS won't write any new dedupditto
blocks.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Issue #8270Closes#8310
Redacted send/receive allows users to send subsets of their data to
a target system. One possible use case for this feature is to not
transmit sensitive information to a data warehousing, test/dev, or
analytics environment. Another is to save space by not replicating
unimportant data within a given dataset, for example in backup tools
like zrepl.
Redacted send/receive is a three-stage process. First, a clone (or
clones) is made of the snapshot to be sent to the target. In this
clone (or clones), all unnecessary or unwanted data is removed or
modified. This clone is then snapshotted to create the "redaction
snapshot" (or snapshots). Second, the new zfs redact command is used
to create a redaction bookmark. The redaction bookmark stores the
list of blocks in a snapshot that were modified by the redaction
snapshot(s). Finally, the redaction bookmark is passed as a parameter
to zfs send. When sending to the snapshot that was redacted, the
redaction bookmark is used to filter out blocks that contain sensitive
or unwanted information, and those blocks are not included in the send
stream. When sending from the redaction bookmark, the blocks it
contains are considered as candidate blocks in addition to those
blocks in the destination snapshot that were modified since the
creation_txg of the redaction bookmark. This step is necessary to
allow the target to rehydrate data in the case where some blocks are
accidentally or unnecessarily modified in the redaction snapshot.
The changes to bookmarks to enable fast space estimation involve
adding deadlists to bookmarks. There is also logic to manage the
life cycles of these deadlists.
The new size estimation process operates in cases where previously
an accurate estimate could not be provided. In those cases, a send
is performed where no data blocks are read, reducing the runtime
significantly and providing a byte-accurate size estimate.
Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Chris Williamson <chris.williamson@delphix.com>
Reviewed-by: Pavel Zhakarov <pavel.zakharov@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#7958
If the zfs_remove_max_segment tunable is changed to be not a multiple of
the sector size, then the device removal code will malfunction and try
to create mappings that are smaller than one sector, leading to a panic.
On debug bits this assertion will fail in spa_vdev_copy_segment():
ASSERT3U(DVA_GET_ASIZE(&dst), ==, size);
On nondebug, the system panics with a stack like:
metaslab_free_concrete()
metaslab_free_impl()
metaslab_free_impl_cb()
vdev_indirect_remap()
free_from_removing_vdev()
metaslab_free_impl()
metaslab_free_dva()
metaslab_free()
Fortunately, the default for zfs_remove_max_segment is 1MB, so this
can't occur by default. We hit it during this test because
removal_remap.ksh changes zfs_remove_max_segment to 1KB. When testing on
4KB-sector disks, we hit the bug.
This change makes the zfs_remove_max_segment tunable more robust,
automatically rounding it up to a multiple of the sector size. We also
turn some key assertions into VERIFY's so that similar bugs would be
caught before they are encoded on disk (and thus avoid a
panic-reboot-loop).
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-61342
Closes#8893
Starting in sync pass 5 (zfs_sync_pass_dont_compress), we disable
compression (including of metadata). Ostensibly this helps the sync
passes to converge (i.e. for a sync pass to not need to allocate
anything because it is 100% overwrites).
However, in practice it increases the average number of sync passes,
because when we turn compression off, a lot of block's size will change
and thus we have to re-allocate (not overwrite) them. It also increases
the number of 128KB allocations (e.g. for indirect blocks and spacemaps)
because these will not be compressed. The 128K allocations are
especially detrimental to performance on highly fragmented systems,
which may have very few free segments of this size, and may need to load
new metaslabs to satisfy 128K allocations.
We should increase zfs_sync_pass_dont_compress. In practice on a highly
fragmented system we see a few 5-pass txg's, a tiny number of 6-pass
txg's, and no txg's with more than 6 passes.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-63431
Closes#8892
On fragmented pools with high-performance storage, the looping in
metaslab_block_picker() can become the performance-limiting bottleneck.
When looking for a larger block (e.g. a 128K block for the ZIL), we may
search through many free segments (up to hundreds of thousands) to find
one that is large enough to satisfy the allocation. This can take a long
time (up to dozens of ms), and is done while holding the ms_lock, which
other threads may spin waiting for.
When this performance problem is encountered, profiling will show
high CPU time in metaslab_block_picker, as well as in mutex_enter from
various callers.
The problem is very evident on a test system with a sync write workload
with 8K writes to a recordsize=8k filesystem, with 4TB of SSD storage,
84% full and 88% fragmented. It has also been observed on production
systems with 90TB of storage, 76% full and 87% fragmented.
The fix is to change metaslab_df_alloc() to search only up to 16MB from
the previous allocation (of this alignment). After that, we will pick a
segment that is of the exact size requested (or larger). This reduces
the number of iterations to a few hundred on fragmented pools (a ~100x
improvement).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-62324
Closes#8877
When iterating over a ZAP object, we're almost always certain to iterate
over the entire object. If there are multiple leaf blocks, we can
realize a performance win by issuing reads for all the leaf blocks in
parallel when the iteration begins.
For example, if we have 10,000 snapshots, "zfs destroy -nv
pool/fs@1%9999" can take 30 minutes when the cache is cold. This change
provides a >3x performance improvement, by issuing the reads for all ~64
blocks of each ZAP object in parallel.
Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-58347
Closes#8862
We've observed that on some highly fragmented pools, most metaslab
allocations are small (~2-8KB), but there are some large, 128K
allocations. The large allocations are for ZIL blocks. If there is a
lot of fragmentation, the large allocations can be hard to satisfy.
The most common impact of this is that we need to check (and thus load)
lots of metaslabs from the ZIL allocation code path, causing sync writes
to wait for metaslabs to load, which can take a second or more. In the
worst case, we may not be able to satisfy the allocation, in which case
the ZIL will resort to txg_wait_synced() to ensure the change is on
disk.
To provide a workaround for this, this change adds a tunable that can
reduce the size of ZIL blocks.
External-issue: DLPX-61719
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8865
Historically while doing performance testing we've noticed that IOPS
can be significantly reduced when all vdevs in the pool are hitting
the zfs_mg_fragmentation_threshold percentage. Specifically in a
hypothetical pool with two vdevs, what can happen is the following:
Vdev A would go above that threshold and only vdev B would be used.
Then vdev B would pass that threshold but vdev A would go below it
(we've been freeing from A to allocate to B). The allocations would
go back and forth utilizing one vdev at a time with IOPS taking a hit.
Empirically, we've seen that our vdev selection for allocations is
good enough that fragmentation increases uniformly across all vdevs
the majority of the time. Thus we set the threshold percentage high
enough to avoid hitting the speed bump on pools that are being pushed
to the edge. We effectively disable its effect in the majority of the
cases but we don't remove (at least for now) just in case we hit any
weird behavior in the future.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8859
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Peter Wirdemo <peter.wirdemo@gmail.com>
Closes#8855
Various changes (many by me) have been made to the man pages without
bumping their dates. I have now corrected them based on the last commit
to each file. I also added the script I used to make these changes.
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8710
Exported and documented a new module parameter.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes#8706
When receiving a DRR_OBJECT record the receive_object() function
needs to determine how to handle a spill block associated with the
object. It may need to be removed or kept depending on how the
object was modified at the source.
This determination is currently accomplished using a heuristic which
takes in to account the DRR_OBJECT record and the existing object
properties. This is a problem because there isn't quite enough
information available to do the right thing under all circumstances.
For example, when only the block size changes the spill block is
removed when it should be kept.
What's needed to resolve this is an additional flag in the DRR_OBJECT
which indicates if the object being received references a spill block.
The DRR_OBJECT_SPILL flag was added for this purpose. When set then
the object references a spill block and it must be kept. Either
it is update to date, or it will be replaced by a subsequent DRR_SPILL
record. Conversely, if the object being received doesn't reference
a spill block then any existing spill block should always be removed.
Since previous versions of ZFS do not understand this new flag
additional DRR_SPILL records will be inserted in to the stream.
This has the advantage of being fully backward compatible. Existing
ZFS systems receiving this stream will recreate the spill block if
it was incorrectly removed. Updated ZFS versions will correctly
ignore the additional spill blocks which can be identified by
checking for the DRR_SPILL_UNMODIFIED flag.
The small downside to this approach is that is may increase the size
of the stream and of the received snapshot on previous versions of
ZFS. Additionally, when receiving streams generated by previous
unpatched versions of ZFS spill blocks may still be lost.
OpenZFS-issue: https://www.illumos.org/issues/9952
FreeBSD-issue: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=233277
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#8668
This standardizes the language on "deduplication tables" rather than
"dedup data" (which might be read as the data blocks rather than the
DDT). Likewise, it standardizes on "small file blocks". It also
standardizes on "normal" rather than using both "normal" and "general"
in the same paragraph. I also replaced "non-specified" with the more
explicit "non-dedup/special".
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8713
Authored by: Jason King <jason.king@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Andy Fiddaman <andy@omniosce.org>
Reviewed by: Peter Tribble <peter.tribble@gmail.com>
Reviewed by: Gergő Mihály Doma <domag02@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Richard Laager <rlaager@wiktel.com>
OpenZFS-issue: https://www.illumos.org/issues/10473
OpenZFS-commit: https://github.com/illumos/illumos-gate/commit/736e67003Closes#8711
The 'zpool resilver' command requires that the resilver_defer
feature is active on the pool. Unfortunately, the check for
this was left out of the original patch. This commit simply
corrects this so that the command properly returns an error
in this case.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8700
Currently, it is possible for the 'zpool scrub' command to
progress slightly beyond 100% due to concurrent changes
happening on the live pool. This behavior is expected, but
the userspace code for 'zpool status' would subtract the
expected amount of data from the amount of data already
scrubbed, resulting in a negative integer being casted to a
large positive one. This number was then used to calculate
the estimated completion time, resulting in wildly wrong
results. This code changes the behavior so that 'zpool status'
does not attempt to report an estimate during this period.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8611Closes#8687
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8691
- Remove the language that "all user data" is encrypted. This is to
avoid misunderstandings or arguments about what is "user data",
especially in light of "user properties".
- Document that properties are unencrypted.
- Document that snapshot names are unencrypted.
- For consistency with the rest of the zfs.8 man page, use "ZFS" as the
generic noun, not (bolded) "zfs". The latter refers to the command.
Likewise, use "ZFS" instead of "the kernel module".
- Give "a passphrase" as an example of a "user's key".
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8652
This adds the encryption copies=3 limitation language into the copies
property section.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8651
This documents, in zpool.8, that dedupditto is deprecated and will be
made to have no effect in a future release.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8650
As far as I know and can tell from testing, \fB\fB...\fR\fR is exactly
equivalent to \fB...\fR.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8641
The features are sorted in the en_US locale, not the C locale.
Specifically, that means that bookmark_v2 comes _after_ bookmarks.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8641
Brian Behlendorf
Paul Zuchowski
Kjeld Schouten
Ross Williams
Romain Dolbeau
Richard Yao
John Gallagher
Andrea Gelmini
Paul Dagnelie
George Wilson
Serapheim Dimitropoulos
Sara Hartse
Pavel Zakharov
Mike Gerdts
Antonio Russo
loli10K
Matthew Ahrens
Tom Caputi
Peter Wirdemo
Richard Laager
DeHackEd