Shared ssd disc for host and journal

[Norman Uittenbogaart]

How do I share a SSD with proxmox host and use it for journal for Ceph?
I tried pvedaemon /dev/sdb --journal_dev /dev/sda2

This works but creating the second OSD, errors out because they use the same journal.
Should I make different partitions for all OSD's?
Or is there another way?

 

[Norman Uittenbogaart]

Solved this issue.

Partition the SSD with the space you need for Proxmox and keep the rest 'free', then you can just use the webinterface and choose the disc als journal.
It will not overwrite the proxmox installation but create new partitions on the remaining space.
It is a major speed increase on just using the spinners.

 

[nethfel]

It's rather unwise to store your journals on the same device as your boot drive - you really ought to keep your journal and OSD drives separate from your boot drive - the journal drive will have a lot more activity on it and will have a higher chance of failure then a boot drive will due to the nature of ceph activity, and if that SSD goes, you will loose your boot drive, journal and all associated OSDs. If you keep the drive separate, if the journal drive dies, it won't also take down the entire box, just the associated OSD drives.