hello, there is no single workload, but a bunch of VMs the do a lot of different things many of which do not special performance demands. The VMs that do need speed are NFS Fileservers and SMBservers.
And exactly these servers seem to benefit from the larger block size. The two I tested mostly on are fileservers. Aside from bonnie++ I also tested writing and reading files especially many small ones. This also works very good and a fact that at the beginning of my search was not true is now: The proxmox/ceph solution is faster and in some disciplines much faster than the old xenbased with ISCSI storage as a backend. Thanks Rainer Am 21.04.20 um 16:01 schrieb Alwin Antreich: > On Tue, Apr 21, 2020 at 03:34:47PM +0200, Rainer Krienke wrote: >> Hello, >> >> just wanted to thank you for your help and to tell you that I found the >> culprit that made my read-perfomance look rarther small on a proxmox VM >> with a LV based on 4 disks (rdbs). The best result using bonnie++ as a >> test was about 100MBytes/sec on a single VM read performance. >> >> I remembered that right after I switched to LVM striping I had tested >> the default block size LVM would use which was 64K. I found this value >> rather small and replaces it by 512K, which increased read and write >> speed. >> >> I remenbered this fact and again changed the stripe size to the default >> RBD object size which is 4MB. Using this value the read performance went >> up to 400MBytes/sec and if I run two bonnies on two different VMs the >> total read performance in ceph is about 800MBytes/sec >> The write performance in this 2VMs test is about 1.2GByte/sec. > The 4 MB chunk size is good for Ceph. But how is the intended workload > performing on those VMs? > > -- > Cheers, > Alwin > > _______________________________________________ > pve-user mailing list > email@example.com > https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user > -- Rainer Krienke, Uni Koblenz, Rechenzentrum, A22, Universitaetsstrasse 1 56070 Koblenz, Web: http://www.uni-koblenz.de/~krienke, Tel: +49261287 1312 PGP: http://www.uni-koblenz.de/~krienke/mypgp.html, Fax: +49261287 1001312 _______________________________________________ pve-user mailing list firstname.lastname@example.org https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user