Re: [ovirt-users] very very bad iscsi performance

[Philip Brown]

yes I am testing small writes. "oltp workload" means, simulation of OLTP 
database access.

You asked me to test the speed of iscsi from another host, which is very 
reasonable. So here are the results,
run from another node in the ovirt cluster.
Setup is using:

 - exact same vg device, exported via iscsi
 - mounted directly into another physical host running centos 7, rather than a 
VM running on it
 -   literaly the same filesystem, again, mounted noatime

I ran the same oltp workload. this setup gives the following results over 2 
runs.

 grep Summary oltp.iscsimount.?
oltp.iscsimount.1:35906: 63.433: IO Summary: 648762 ops, 10811.365 ops/s, 
(5375/5381 r/w),  21.4mb/s,    475us cpu/op,   1.3ms latency
oltp.iscsimount.2:36830: 61.072: IO Summary: 824557 ops, 13741.050 ops/s, 
(6844/6826 r/w),  27.2mb/s,    429us cpu/op,   1.1ms latency


As requested, I attach virsh output, and qemu log

vm-qemu.log
Description: Text Data

virsh.log
Description: Text Data