Running replace.osd on Storage Cluster Fails to Repalce Destroyed Disk

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Environment

SUSE Enterprise Storage 5 (SES5)
SUSE Linux Enterprise Server 12 Service Pack 3 (SLES 12 SP3)

Situation

After following the documentation steps to replace an OSD drive in SES5 using ceph replace.osd, the disk was not replaced as expected.

Resolution

Extra steps need to be taken to replace a destroyed drive. In the example below, the follow values will be used.

ses5node111 - the cluster admin node
ses5node114 - the storage node on which the affected OSD resides.
/dev/sda - the physcial block device for osd.15
/dev/disk/by-id/scsi-SQEMU_QEMU_HARDDISK_ses5node114_osdq - the symbolic link to /dev/sda
osd.15 - the osd ID assoicated with /dev/sda

The following were used to simulate a destroyed OSD disk

ses5node114:~ # sfdisk -f --delete /dev/sda
ses5node114:~ # reboot

The /dev/sda device was removed and a new /dev/sda device added

Replace the destroyed disk
1. ses5node111:~ # salt-run disengage.safety
2. ses5node111:~ # salt-run replace.osd 15
3. ses5node114:~ # rm /etc/ceph/destroyedOSD.yml
4. ses5node111:~ # vi /srv/pillar/ceph/proposals/profile-default/stack/default/ceph/minions/ses5node114.yml
Add "replace: True" to the affected disk in the *.yml file. For example,
Change:
      /dev/disk/by-id/scsi-SQEMU_QEMU_HARDDISK_ses5node114_osdq:
        format: bluestore

to:

      /dev/disk/by-id/scsi-SQEMU_QEMU_HARDDISK_ses5node114_osdq:
        format: bluestore
        replace: True

5. ses5node111:~ # salt-run state.orch ceph.stage.2
6. ses5node111:~ # salt-run state.orch ceph.stage.3

Cause

The ceph replace.osd option expects the /dev/disk/by-path reference to the physical device to stay the same. When the disk partition was destroyed, the /dev/disk/by-path link changed.

Disclaimer

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