SSDs don't work like that. If you have a 100GB SSD and a 10GB partition and don't use the rest of your disk... your 10GB partition isn't limited to 10% of the total SSDs speed. You can use the full speed of the SSD with the 10GB partition. There is literally no difference if you have 3x 5GB partitions or a single 15GB partition if they are being used for the same purpose.
On Wed, Jun 7, 2017 at 3:29 PM Lazuardi Nasution <mrxlazuardin@xxxxxxxxx> wrote:
HI Reed,That is what I'm doing right now, separate journal SSD partition for each OSD HDD. I just thinking of possibility to have better peak write performance without consuming more SSD capacity due to possibility of using larger journal of an OSD if other OSDs don't use it at same time. For example, if I have 3 OSDs each with 5GB journal partition, the write performance will be limited of 5GB journal. If I can make it as 15GB single journal partition for all OSDs, I think I can have 15GB peak write performance possibility if only one OSD writes at the same time (or 7.5GB peak write performance if 2 OSD write at the same time) without consuming more SSD capacity. On reality, not all OSDs write at same time, right?Best regards,On Thu, Jun 8, 2017 at 2:09 AM, Reed Dier <reed.dier@xxxxxxxxxxx> wrote:As far as I am aware, you need separate logical partitions for each OSD’s journal.
So I have an NVMe drive that serves as a journal for 10 OSD’s, thus I have 10 separate partitions, 1 for each OSD.
Hope that helps,
Reed_______________________________________________
> On Jun 7, 2017, at 1:54 PM, Lazuardi Nasution <mrxlazuardin@xxxxxxxxx> wrote:
>
> Hi,
>
> Is it possible to have single external journal for more than one OSD without doing any partitioning or at least only single partition on journal disk? For example, I want to have single SSD as external journal for some OSD HDDs but without doing any partitioning or at least only single partition on SSD.
>
> 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
