This PR changes "master" to "main" in the
basic_workflow.rst file. I have even changed
"master" to "main" in some terminal output from
several years ago. This isn't historically ac-
curate, of course, but my hope is that this change
will prevent someone in the future from being con-
fused about why an antiquated branch name is ref-
erred to.
Signed-off-by: Zac Dover <zac.dover@gmail.com>
Harmonize network throughput notation, minor tweaks to wording.
Followup to #46637
Signed-off-by: Anthony D'Atri <anthonyeleven@users.noreply.github.com>
This PR changes all reference to the "master" branch
to references to the "main" branch (because we renamed
"master" to main", and the docs now need to reflect that).
Signed-off-by: Zac Dover <zac.dover@gmail.com>
This rewrites the first two-thirds of the "Networks"
section of the Hardware Recommendations page in the
Intro to Ceph document. I have tried to divide the
techincal content in this section into subsections
that foreground the various subjects covered.
Signed-off-by: Zac Dover <zac.dover@gmail.com>
This PR makes the "Ceph OSDs" and "MDSs" bullet points
parallel by naming "object storage daemon" before referring
to the (admittedly more common and colloquial, but surely
unknown to people who genuinely require a document called
'Intro') acronym "OSD".
Signed-off-by: Zac Dover <zac.dover@gmail.com>
This PR supersedes https://github.com/ceph/ceph/pull/46584
and makes changes suggested by Anthony D'Atri that improve
the coherence and consistency of the paragraph that explains
the basics of the CRUSH algorithm.
Signed-off-by: Zac Dover <zac.dover@gmail.com>
* refs/pull/46421/head:
doc/dev: move option -R to a different section of doc
Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
Reviewed-by: Anthony D Atri <anthony.datri@gmail.com>
It's incorrect to pass option "-R fail" to the teuthology-suite command
meant for triggering tests for first time. teuthology-suite command will
fail if "-R" is passed without "-r". Therefore, move this option and its
description from the section meant for triggering tests for first time
to the section dedicated to re-running of tests.
Signed-off-by: Rishabh Dave <ridave@redhat.com>
* refs/pull/46516/head:
doc/dev/developer_guide/testing_integration_tests: document how to test custom kernels
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Anthony D Atri <anthony.datri@gmail.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Add documentation for subvolume group quota along
with 'subvolumegroup resize' and 'subvolumegroup info'
commands
Fixes: https://tracker.ceph.com/issues/53509
Signed-off-by: Kotresh HR <khiremat@redhat.com>
CreatePrimaryRequest::unlink_peer() invoked via "rbd mirror image
snapshot" command or via rbd_support mgr module when creating a new
scheduled mirror snapshot at rbd_mirroring_max_mirroring_snapshots
capacity on the primary cluster can race with Replayer::unlink_peer()
invoked by rbd-mirror when finishing syncing an older snapshot on the
secondary cluster. Consider the following:
[ primary: primary-snap1, primary-snap2, primary-snap3
secondary: non-primary-snap1 (complete), non-primary-snap2 (syncing) ]
0. rbd-mirror is syncing snap1..snap2 delta
1. rbd_support creates primary-snap4
2. due to rbd_mirroring_max_mirroring_snapshots == 3, rbd_support picks
primary-snap3 for unlinking
3. rbd-mirror finishes syncing snap1..snap2 delta and marks
non-primary-snap2 complete
[ snap1 (the old base) is no longer needed on either cluster ]
4. rbd-mirror unlinks and removes primary-snap1
5. rbd-mirror removes non-primary-snap1
6. rbd-mirror picks snap2 as the new base
7. rbd-mirror creates non-primary-snap3 and starts syncing snap2..snap3
delta
[ primary: primary-snap2, primary-snap3, primary-snap4
secondary: non-primary-snap2 (complete), non-primary-snap3 (syncing) ]
8. rbd_support unlinks and removes primary-snap3 which is in-use by
rbd-mirror
If snap trimming on the primary cluster kicks in soon enough, the
secondary image becomes corrupted: rbd-mirror would eventually finish
"syncing" non-primary-snap3 and mark it complete in spite of bogus data
in the HEAD -- the primary cluster OSDs would start returning ENOENT
for snap trimmed objects. Luckily, rbd-mirror's attempt to pick snap3
as the new base would wedge the replayer with "split-brain detected:
failed to find matching non-primary snapshot in remote image" error.
Before commit a888bff8d0 ("librbd/mirror: tweak which snapshot is
unlinked when at capacity") this could happen pretty much all the time
as it was the second oldest snapshot that was unlinked. This commit
changed it to be the third oldest snapshot, turning this into a more
narrow but still very much possible to hit race.
Unfortunately this race condition appears to be inherent to the way
snapshot-based mirroring is currently implemented:
a. when mirror snapshots are created on the producer side of the
snapshot queue, they are already linked
b. mirror snapshots can be concurrently unlinked/removed on both
sides of the snapshot queue by non-cooperating clients (local
rbd_mirror_image_create_snapshot() vs remote rbd-mirror)
c. with mirror peer links off the list due to (a), there is no
existing way for rbd-mirror to persistently mark a snapshot as
in-use
As a workaround, bump rbd_mirroring_max_mirroring_snapshots to 5 and
always unlink the newest snapshot (i.e. slot 4) instead of the third
oldest snapshot (i.e. slot 2). Hopefully this gives enough leeway,
as rbd-mirror would need to sync two snapshots (i.e. transition from
syncing 0-1 to 1-2 and then to 2-3) before potentially colliding with
rbd_mirror_image_create_snapshot() on slot 4.
Fixes: https://tracker.ceph.com/issues/55803
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This PR corrects some usage errors in the "Memory" section
of the hardware-recommendations.rst file. It also closes
some opened but never closed parentheses.
Signed-off-by: Zac Dover <zac.dover@gmail.com>
Set custom metadata on the snapshot as a key-value pair using
$ ceph fs subvolume snapshot metadata set <vol_name> <subvol_name> <snap_name> <key_name> <value> [--group_name <subvol_group_name>]
note: If the key_name already exists then the old value will get replaced by the new value.
note: The key_name and value should be a string of ASCII characters (as specified in python's string.printable). The key_name is case-insensitive and always stored in lower case.
note: Custom metadata on a snapshots is not preserved when snapshotting the subvolume, and hence, is also not preserved when cloning the subvolume snapshot.
Get custom metadata set on the snapshot using the metadata key::
$ ceph fs subvolume snapshot metadata get <vol_name> <subvol_name> <snap_name> <key_name> [--group_name <subvol_group_name>]
List custom metadata (key-value pairs) set on the snapshot using::
$ ceph fs subvolume snapshot metadata ls <vol_name> <subvol_name> <snap_name> [--group_name <subvol_group_name>]
Remove custom metadata set on the snapshot using the metadata key::
$ ceph fs subvolume snapshot metadata rm <vol_name> <subvol_name> <snap_name> <key_name> [--group_name <subvol_group_name>] [--force]
Using the '--force' flag allows the command to succeed that would otherwise fail if the metadata key did not exist.
Fixes: https://tracker.ceph.com/issues/55401
Signed-off-by: Nikhilkumar Shelke <nshelke@redhat.com>
