Commit Graph

3 Commits

Author SHA1 Message Date
Ryan Moeller 6706552ea6
Remove hard coded "Linux" OS from manpages
The recommended practice for `.Os` on FreeBSD is to not specify any
arguments.  The correct OS name is used automatically.

Oddly enough, on the Linux distro I tested this on (CentOS 7), the man
pager defaulted to displaying "BSD" as the OS rather than "Linux".  To
accommodate this, tack " Linux" back on in an install hook on Linux.
This is much simpler than removing it for FreeBSD when vendored in the
base system.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10760
2020-08-21 11:55:47 -07:00
George Amanakis b7654bd794
Trim L2ARC
The l2arc_evict() function is responsible for evicting buffers which
reference the next bytes of the L2ARC device to be overwritten. Teach
this function to additionally TRIM that vdev space before it is
overwritten if the device has been filled with data. This is done by
vdev_trim_simple() which trims by issuing a new type of TRIM,
TRIM_TYPE_SIMPLE.

We also implement a "Trim Ahead" feature. It is a zfs module parameter,
expressed in % of the current write size. This trims ahead of the
current write size. A minimum of 64MB will be trimmed. The default is 0
which disables TRIM on L2ARC as it can put significant stress to
underlying storage devices. To enable TRIM on L2ARC we set
l2arc_trim_ahead > 0.

We also implement TRIM of the whole cache device upon addition to a
pool, pool creation or when the header of the device is invalid upon
importing a pool or onlining a cache device. This is dependent on
l2arc_trim_ahead > 0. TRIM of the whole device is done with
TRIM_TYPE_MANUAL so that its status can be monitored by zpool status -t.
We save the TRIM state for the whole device and the time of completion
on-disk in the header, and restore these upon L2ARC rebuild so that
zpool status -t can correctly report them. Whole device TRIM is done
asynchronously so that the user can export of the pool or remove the
cache device while it is trimming (ie if it is too slow).

We do not TRIM the whole device if persistent L2ARC has been disabled by
l2arc_rebuild_enabled = 0 because we may not want to lose all cached
buffers (eg we may want to import the pool with
l2arc_rebuild_enabled = 0 only once because of memory pressure). If
persistent L2ARC has been disabled by setting the module parameter
l2arc_rebuild_blocks_min_l2size to a value greater than the size of the
cache device then the whole device is trimmed upon creation or import of
a pool if l2arc_trim_ahead > 0.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam D. Moss <c@yotes.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #9713
Closes #9789 
Closes #10224
2020-06-09 10:15:08 -07:00
Ross Williams c5ebfbbe19 Reorganize zpool(8) man page into sections
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
2019-11-13 09:21:07 -08:00