Task #5770
Updated by Nico Schottelius about 6 years ago
* Detailed explanation
* Including commands of megacli
* Including motivation
h2. Disk handling
Our servers are using Perc H700 or H800 disk controllers. The tool **megacli** can be used to manage them.
h3. Handling foreign configuration
When plugging a disk into a server that was configured / used in a different server before, we need to clear the previous configuration.
Listing all known foreign configuration using **megacli -CfgForeign -Scan -aALL**.
Remove/clear the foreign configuration using
<pre>
# for instance -L5 -a0 or -L2 -a1
megacli -DiscardPreservedCache -L<slot-or-ID> -a<Controller>
</pre>
h3. Removal of a disk
If a (dead or intact) disk is being removed from the system, the system will HANG on the next reboot, complaining about it missing. For that reason AFTER removing a disk, we need to "clear the cache":
<pre>
# Get list of caches that need to be cleared
megacli -GetPreservedCacheList -aALL
# Clear cache: -L0 -a1
megacli -DiscardPreservedCache -L<??> -a<controller>
</pre>
h2. How to move an OSD (Disk, SSD) to another server
* Use ceph-osd-stop-disable from ungleich tools to stop / disable the OSD
* Clear the raid controller information
* Insert disk into new host
* Clear the foreign configuration (megacli)
* [add it to the system with megacli]
* OSD should automatically come up afterwards
** Check using **ceph osd tree**