Hello there,
At first I thought I had a performance problem with virtio-scsi on
Windows, but after thorough experimentation, I finally found that my
performance problem was related to the way I share my storage using NFS.
Using the settings suggested on the oVirt website for the /etc/exports
file, I implemented the following line:
/storage
*(rw,sync,no_subtree_check,all_squash,anonuid=36,anongid=36)
The underlying filesystem is ext4.
In the end, whatever the VM I am running through this NFS export, I get
extremely poor write performance, like sub-100 IOPS (my disks usually
can do 800-1k). Under the hood, iotop shows that my host IO is all taken
up by jbd2, and if I understand correctly, it is the ext4 logging
process.
I have read that using the "async" option in my NFS export is unsafe,
like if my host crashes during a write operation, it could corrupt my VM
Disks.
What is the best combination of filesystem / settings if I want to go
with NFS sync? Is someone getting good performance with the same options
as me? if so, why do I get such abysmal IOPS numbers?
Thanks!
J-F Courteau
_______________________________________________
Users mailing list
Users@ovirt.org
http://lists.ovirt.org/mailman/listinfo/users
