Hi Alfredo,
I want to have such LVs on NVME is for having the best performance. I have read that having 4 OSDs per NVME is the best one. Beside, since there is only one NVMe, I think that sacrificing small portion of NVME to accelerate block.db of HDD OSDs is good too. About VG and LV naming, I think it is just for cosmetic purposes only. It seem that I have to do it with manual VG and LV creation if I want to do it with ceph-ansible.
Best regards,
On Sat, May 11, 2019, 02:42 Alfredo Deza <adeza@xxxxxxxxxx> wrote:
On Fri, May 10, 2019 at 3:21 PM Lazuardi Nasution
<mrxlazuardin@xxxxxxxxx> wrote:
>
> Hi Alfredo,
>
> Thank you for your answer, it is very helpful. Do you mean that --osds-per-device=3 is mistyped? It should be --osds-per-device=4 to create 4 OSDs as expected, right? I'm trying to not create it by specifying manually created LVM to have consistent ceph way of VG and LV naming.
Typo, yes... good catch!
The VG/LV naming isn't a super advantage here because it was done to
avoid collisions when creating them programmatically :) I don't know
why you want to place OSDs in this way which we aren't recommending
anywhere, you might as well go with what batch proposes.
>
> By the way, is it possible to do this two ceph-volume batch command by using single ceph-ansible run or I should run twice with different configuration? If it is possible, what should I put on configuration file?
This might be a good example to take why I am recommending against it:
tools will probably not support it. I don't think you can make
ceph-ansible do this, unless you are pre-creating the LVs, which if
using Ansible shouldn't be too hard anyway
>
> Best regards,
>
> On Sat, May 11, 2019, 02:09 Alfredo Deza <adeza@xxxxxxxxxx> wrote:
>>
>> On Fri, May 10, 2019 at 2:43 PM Lazuardi Nasution
>> <mrxlazuardin@xxxxxxxxx> wrote:
>> >
>> > Hi,
>> >
>> > Let's say I have following devices on a host.
>> >
>> > /dev/sda
>> > /dev/sdb
>> > /dev/nvme0n1
>> >
>> > How can I do ceph-volume batch which create bluestore OSD on HDDs and NVME (devided to be 4 OSDs) and put block.db of HDDs on the NVME too? Following are what I'm expecting on created LVs.
>>
>> You can, but it isn't easy (batch is meant to be opinionated) and what
>> you are proposing is a bit of an odd scenario that doesn't fit well
>> with what the batch command will want to do, which is: create OSDs
>> from a list
>> of devices and do the most optimal layout possible.
>>
>> I would suggest strongly to just use `ceph-volume lvm create` with
>> pre-made LVs that you can pass into it to arrange things in the way
>> you need. However, you might still be able to force batch here by
>> defining
>> the block.db sizes in ceph.conf, otherwise ceph-volume falls back to
>> "as large as possible". Having defined a size (say, 10GB) you can do
>> this:
>>
>> ceph-volume lvm batch /dev/sda /dev/sdb /dev/nvme0n1
>> ceph-volume lvm batch --osds-per-device=3 /dev/nvme0n1
>>
>> Again, I highly recommend against this setup and trying to make batch
>> do this - not 100% it will work...
>> >
>> > /dev/sda: DATA0
>> > /dev/sdb: DATA1
>> > /dev/nvme0n1: DB0 | DB1 | DATA2 | DATA3 | DATA4 | DATA5
>> >
>> > Best regards,
>> > _______________________________________________
>> > ceph-users mailing list
>> > ceph-users@xxxxxxxxxxxxxx
>> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
