Does SSD Journal improve the performance?

Does SSD Journal improve the performance?

[hzwulibin-Re5JQEeQqe8AvxtiuMwx3w]

[-- Attachment #1.1: Type: text/plain, Size: 791 bytes --]

Hi, 

It should be sure SSD Journal will improve the performance of IOPS. But unfortunately it's not in my test.

I have two pools with the same number of osds:
pool1, ssdj_sas:
9 osd servers, 8 OSDs(SAS) on every server
Journal on SSD, one SSD disk for 4 SAS disks.

pool 2, sas:
9 osd servers, 8 OSDs(SAS) on every server
Journal on SAS disk itself。

I use rbd to create a volume in pool1 and pool2 separately and use fio to test
the rand write IOPS。here is the fio configuration:

rw=randwrite
ioengine=libaio
direct=1
iodepth=128
bs=4k
numjobs=1

The result i got is:
volume in pool1, about 5k
volume in pool2, about 12k

It's a big gap here, anyone can give me some suggestion here?

ceph version: hammer(0.94.3)
kernel: 3.10



hzwulibin@gmail.com

[-- Attachment #1.2: Type: text/html, Size: 4488 bytes --]

[-- Attachment #2: Type: text/plain, Size: 178 bytes --]

_______________________________________________
ceph-users mailing list
ceph-users-idqoXFIVOFJgJs9I8MT0rw@public.gmane.org
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com