When the blkdevmapper init container initializes we must override any
existing special block. This will prevent re-using a different disk on
the OSD on PVC scenario.
Adding "--remove-destination" to the cp line will remove each existing
destination file before attempting to open it.
We **MUST** do this otherwise in environment where PVCs are dynamic, restarting the deployment will cause conflicts
When restarting the OSD, the PVC block might end up with a different Kernel disk allocation
For instance, prior to restart the block was mapped to 8:32 and when re-attached it was on 8:16
The previous "block" is still 8:32 so if we don't override it we will try to initialize on a disk that is not an OSD or worse another OSD
This is mainly because in https://github.com/rook/rook/commit/ae8dcf7cc3b51cf8ca7da22f48b7a58887536c4f we switched to use HostPath to store the OSD data
Since HostPath is not ephemeral, the block file must be re-hydrated each time the deployment starts
The test uses "==" instead of numbers since the stat command will print
an hex number and thus we won't always get integer, e,g: major/minor
value 202:13312 will be return ca:3400.
Example run of the new init container:
+ PVC_SOURCE=/set1-data-168h7m
+ PVC_DEST=/var/lib/ceph/osd/ceph-0/block
+ CP_ARGS=(--archive --dereference --verbose)
+ '[' -b /var/lib/ceph/osd/ceph-0/block ']'
++ stat -c %t%T /set1-data-168h7m
+ PVC_SOURCE_MAJ_MIN=ca6100
++ stat -c %t%T /var/lib/ceph/osd/ceph-0/block
PVC's source major/minor numbers changed
removed '/var/lib/ceph/osd/ceph-0/block'
'/set1-data-168h7m' -> '/var/lib/ceph/osd/ceph-0/block'
+ PVC_DEST_MAJ_MIN=ca4000
+ [[ ca6100 == \c\a\4\0\0\0 ]]
+ echo 'PVC'\''s source major/minor numbers changed'
+ CP_ARGS+=(--remove-destination)
+ cp --archive --dereference --verbose --remove-destination /set1-data-168h7m /var/lib/ceph/osd/ceph-0/block
Test procedure:
$ oc -n rook-ceph scale deployment rook-ceph-osd-0 --replicas=2
deployment.apps/rook-ceph-osd-0 scaled
Now we have 2 OSDs and one is crashlooping, which is expected:
rook-ceph-osd-0-66964f6d-2cwqq 0/1 Init:CrashLoopBackOff 4 2m12s
rook-ceph-osd-0-66964f6d-pmhlq 1/1 Running 0 6m7s
The logs from the failing container is pretty clear:
+ PVC_SOURCE=/set1-data-168h7m
+ PVC_DEST=/var/lib/ceph/osd/ceph-0/block
+ CP_ARGS=(--archive --dereference --verbose)
+ '[' -b /var/lib/ceph/osd/ceph-0/block ']'
++ stat -c %t%T /set1-data-168h7m
+ PVC_SOURCE_MAJ_MIN=ca6100
++ stat -c %t%T /var/lib/ceph/osd/ceph-0/block
+ PVC_DEST_MAJ_MIN=ca6100
+ [[ ca6100 == \c\a\6\1\0\0 ]]
+ CP_ARGS+=(--no-clobber)
+ cp --archive --dereference --verbose --no-clobber /set1-data-168h7m /var/lib/ceph/osd/ceph-0/block
inferring bluefs devices from bluestore path
/home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos8/DIST/centos8/MACHINE_SIZE/gigantic/release/15.2.8/rpm/el8/BUILD/ceph-15.2.8/src/os/bluestore/BlueStore.cc: In function 'int BlueStore::expand_devices(std::ostream&)' thread 7f2a52d18240 time 2021-02-09T13:27:46.011397+0000
/home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos8/DIST/centos8/MACHINE_SIZE/gigantic/release/15.2.8/rpm/el8/BUILD/ceph-15.2.8/src/os/bluestore/BlueStore.cc: 7090: FAILED ceph_assert(r == 0)
2021-02-09T13:27:46.010+0000 7f2a52d18240 -1 bluestore(/var/lib/ceph/osd/ceph-0) _lock_fsid failed to lock /var/lib/ceph/osd/ceph-0/fsid (is another ceph-osd still running?)(11) Resource temporarily unavailable
ceph version 15.2.8 (bdf3eebcd22d7d0b3dd4d5501bee5bac354d5b55) octopus (stable)
1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x158) [0x7f2a48e236e4]
Acquiring the lock fails, so the OSD won't run.
Now we scale back down:
$ oc -n rook-ceph scale deployment rook-ceph-osd-0 --replicas=1
deployment.apps/rook-ceph-osd-0 scaled
And we can see the last created OSD (the one crash looping) disappears:
rook-ceph-osd-0-66964f6d-2cwqq 0/1 Terminating 5 3m6s
rook-ceph-osd-0-66964f6d-pmhlq 1/1 Running 0 7m1s
Signed-off-by: Sébastien Han <seb@redhat.com>
Sébastien Han
6dc15eb649