Currently, scrubs and resilvers can take an extremely
long time to complete. This is largely due to the fact
that zfs scans process pools in logical order, as
determined by each block's bookmark. This makes sense
from a simplicity perspective, but blocks in zfs are
often scattered randomly across disks, particularly
due to zfs's copy-on-write mechanisms.
This patch improves performance by splitting scrubs
and resilvers into a metadata scanning phase and an IO
issuing phase. The metadata scan reads through the
structure of the pool and gathers an in-memory queue
of I/Os, sorted by size and offset on disk. The issuing
phase will then issue the scrub I/Os as sequentially as
possible, greatly improving performance.
This patch also updates and cleans up some of the scan
code which has not been updated in several years.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Authored-by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Authored-by: Alek Pinchuk <apinchuk@datto.com>
Authored-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#3625Closes#6256
Currently, there is no way to pause a scrub. Pausing may
be useful when the pool is busy with other I/O to preserve
bandwidth.
This patch adds the ability to pause and resume scrubbing.
This is achieved by maintaining a persistent on-disk scrub state.
While the state is 'paused' we do not scrub any more blocks.
We do however perform regular scan housekeeping such as
freeing async destroyed and deadlist blocks while paused.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Reviewed-by: Serapheim Dimitropoulos <serapheimd@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
Closes#6167
4914 zfs on-disk bookmark structure should be named *_phys_t
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
https://www.illumos.org/issues/4914https://github.com/illumos/illumos-gate/commit/7802d7b
Porting notes:
There were a number of zfsonlinux-specific uses of zbookmark_t which
needed to be updated. This should reduce the likelihood of further
problems like issue #2094 from occurring.
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2558
4390 i/o errors when deleting filesystem/zvol can lead to space map corruption
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/4390https://github.com/illumos/illumos-gate/commit/7fd05ac
Porting notes:
Previous stack-reduction efforts in traverse_visitb() caused a fair
number of un-mergable pieces of code. This patch should reduce its
stack footprint a bit more.
The new local bptree_entry_phys_t in bptree_add() is dynamically-allocated
using kmem_zalloc() for the purpose of stack reduction.
The new global zfs_free_leak_on_eio has been defined as an integer
rather than a boolean_t as was the case with the related zfs_recover
global. Also, zfs_free_leak_on_eio's definition has been inserted into
zfs_debug.c for consistency with the existing definition of zfs_recover.
Illumos placed it in spa_misc.c.
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2545
ZoL commit 1421c89 unintentionally changed the disk format in a forward-
compatible, but not backward compatible way. This was accomplished by
adding an entry to zbookmark_t, which is included in a couple of
on-disk structures. That lead to the creation of pools with incorrect
dsl_scan_phys_t objects that could only be imported by versions of ZoL
containing that commit. Such pools cannot be imported by other versions
of ZFS or past versions of ZoL.
The additional field has been removed by the previous commit. However,
affected pools must be imported and scrubbed using a version of ZoL with
this commit applied. This will return the pools to a state in which they
may be imported by other implementations.
The 'zpool import' or 'zpool status' command can be used to determine if
a pool is impacted. A message similar to one of the following means your
pool must be scrubbed to restore compatibility.
$ zpool import
pool: zol-0.6.2-173
id: 1165955789558693437
state: ONLINE
status: Errata #1 detected.
action: The pool can be imported using its name or numeric identifier,
however there is a compatibility issue which should be corrected
by running 'zpool scrub'
see: http://zfsonlinux.org/msg/ZFS-8000-ER
config:
...
$ zpool status
pool: zol-0.6.2-173
state: ONLINE
scan: pool compatibility issue detected.
see: https://github.com/zfsonlinux/zfs/issues/2094
action: To correct the issue run 'zpool scrub'.
config:
...
If there was an async destroy in progress 'zpool import' will prevent
the pool from being imported. Further advice on how to proceed will be
provided by the error message as follows.
$ zpool import
pool: zol-0.6.2-173
id: 1165955789558693437
state: ONLINE
status: Errata #2 detected.
action: The pool can not be imported with this version of ZFS due to an
active asynchronous destroy. Revert to an earlier version and
allow the destroy to complete before updating.
see: http://zfsonlinux.org/msg/ZFS-8000-ER
config:
...
Pools affected by the damaged dsl_scan_phys_t can be detected prior to
an upgrade by running the following command as root:
zdb -dddd poolname 1 | grep -P '^\t\tscan = ' | sed -e 's;scan = ;;' | wc -w
Note that `poolname` must be replaced with the name of the pool you wish
to check. A value of 25 indicates the dsl_scan_phys_t has been damaged.
A value of 24 indicates that the dsl_scan_phys_t is normal. A value of 0
indicates that there has never been a scrub run on the pool.
The regression caused by the change to zbookmark_t never made it into a
tagged release, Gentoo backports, Ubuntu, Debian, Fedora, or EPEL
stable respositorys. Only those using the HEAD version directly from
Github after the 0.6.2 but before the 0.6.3 tag are affected.
This patch does have one limitation that should be mentioned. It will not
detect errata #2 on a pool unless errata #1 is also present. It expected
this will not be a significant problem because pools impacted by errata #2
have a high probably of being impacted by errata #1.
End users can ensure they do no hit this unlikely case by waiting for all
asynchronous destroy operations to complete before updating ZoL. The
presence of any background destroys on any imported pools can be checked
by running `zpool get freeing` as root. This will display a non-zero
value for any pool with an active asynchronous destroy.
Lastly, it is expected that no user data has been lost as a result of
this erratum.
Original-patch-by: Tim Chase <tim@chase2k.com>
Reworked-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2094
3956 ::vdev -r should work with pipelines
3957 ztest should update the cachefile before killing itself
3958 multiple scans can lead to partial resilvering
3959 ddt entries are not always resilvered
3960 dsl_scan can skip over dedup-ed blocks if physical birth != logical birth
3961 freed gang blocks are not resilvered and can cause pool to suspend
3962 ztest should print out zfs debug buffer before exiting
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
References:
https://www.illumos.org/issues/3956https://www.illumos.org/issues/3957https://www.illumos.org/issues/3958https://www.illumos.org/issues/3959https://www.illumos.org/issues/3960https://www.illumos.org/issues/3961https://www.illumos.org/issues/3962illumos/illumos-gate@b4952e17e8
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Porting notes:
1. zfs_dbgmsg_print() is only used in userland. Since we do not have
mdb on Linux, it does not make sense to make it available in the
kernel. This means that a build failure will occur if any future
kernel patch depends on it. However, that is unlikely given that
this functionality was added to support zdb.
2. zfs_dbgmsg_print() is only invoked for -VVV or greater log levels.
This preserves the existing behavior of minimal noise when running
with -V, and -VV.
3. In vdev_config_generate() the call to nvlist_alloc() was not
changed to fnvlist_alloc() because we must pass KM_PUSHPAGE in
the txg_sync context.
3642 dsl_scan_active() should not issue I/O to determine if async
destroying is active
3643 txg_delay should not hold the tc_lock
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Gordon Ross <gwr@nexenta.com>
References:
https://www.illumos.org/issues/3642https://www.illumos.org/issues/3643illumos/illumos-gate@4a92375985
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
Porting Notes:
1. The alignment assumptions for the tx_cpu structure assume that
a kmutex_t is 8 bytes. This isn't true under Linux but tc_pad[]
was adjusted anyway for consistency since this structure was
never carefully aligned in ZoL. If careful alignment does impact
performance significantly this should be reworked to be portable.
2619 asynchronous destruction of ZFS file systems
2747 SPA versioning with zfs feature flags
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Dan Kruchinin <dan.kruchinin@gmail.com>
Approved by: Eric Schrock <Eric.Schrock@delphix.com>
References:
illumos/illumos-gate@53089ab7c8illumos/illumos-gate@ad135b5d64
illumos changeset: 13700:2889e2596bd6
https://www.illumos.org/issues/2619https://www.illumos.org/issues/2747
NOTE: The grub specific changes were not ported. This change
must be made to the Linux grub packages.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
One of the neat tricks an autoconf style project is capable of
is allow configurion/building in a directory other than the
source directory. The major advantage to this is that you can
build the project various different ways while making changes
in a single source tree.
For example, this project is designed to work on various different
Linux distributions each of which work slightly differently. This
means that changes need to verified on each of those supported
distributions perferably before the change is committed to the
public git repo.
Using nfs and custom build directories makes this much easier.
I now have a single source tree in nfs mounted on several different
systems each running a supported distribution. When I make a
change to the source base I suspect may break things I can
concurrently build from the same source on all the systems each
in their own subdirectory.
wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz
tar -xzf zfs-x.y.z.tar.gz
cd zfs-x-y-z
------------------------- run concurrently ----------------------
<ubuntu system> <fedora system> <debian system> <rhel6 system>
mkdir ubuntu mkdir fedora mkdir debian mkdir rhel6
cd ubuntu cd fedora cd debian cd rhel6
../configure ../configure ../configure ../configure
make make make make
make check make check make check make check
This change also moves many of the include headers from individual
incude/sys directories under the modules directory in to a single
top level include directory. This has the advantage of making
the build rules cleaner and logically it makes a bit more sense.
Tom Caputi
Alek P
Matthew Ahrens
Richard Yao
George Wilson
Christopher Siden
Brian Behlendorf