Re: Can ceph-volume manage the LVs optionally used for DB / WAL at all?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On 25.08.23 09:09, Eugen Block wrote:
I'm still not sure if we're on the same page.

Maybe not, I'll respond inline to clarify.

By looking at it seems that ceph-volume wants an LV or partition. So it's apparently not just taking a VG itself? Also if there were multiple VGs / devices , I likely would need to at least pick those.

ceph-volume creates all required VGs/LVs automatically, and the OSD creation happens in batch mode, for example when run by cephadm:
ceph-volume lvm batch --yes /dev/sdb /dev/sdc /dev/sdd

In a non-cephadm deployment you can fiddle with ceph-volume manually, where you also can deploy single OSDs, with or without providing your own pre-built VGs/LVs. In a cephadm deployment manually creating OSDs will result in "stray daemons not managed by cephadm" warnings.

1) I am mostly asking about an non-cephadm environment and would just like to know if ceph-volume can also manage the VG of a DB/WAL device that is used for multiple OSD and create the individual LVs which are used for DB or WAL devices when creating a single OSD. Below you give an example "before we upgraded to Pacific" in which you run lvcreate manually. Is that not required anymore with >= Quincy? 2) Even with cephadm there is the "db_devices" as part of the drivegroups. But the question remains if cephadm can use a single db_device for multiple OSDs.

Before we upgraded to Pacific we did manage our block.db devices manually with pre-built LVs, e.g.:

$ lvcreate -L 30G -n bluefsdb-30 ceph-journals
$ ceph-volume lvm create --data /dev/sdh --block.db ceph-journals/bluefsdb-30

As asked and explained in the paragraph above, this is what I am currently doing (lvcreate + ceph-volume lvm create). My question therefore is, if ceph-volume (!) could somehow create this LV for the DB automagically if I'd just give it a device (or existing VG)?

Thank you very much for your patience in clarifying and responding to my questions.


ceph-users mailing list -- ceph-users@xxxxxxx
To unsubscribe send an email to ceph-users-leave@xxxxxxx

[Index of Archives]     [Information on CEPH]     [Linux Filesystem Development]     [Ceph Development]     [Ceph Large]     [Ceph Dev]     [Linux USB Development]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [xfs]

  Powered by Linux