Hello everyone,
When I use a simple qemu-img convert to move from a storage of my choice onto a multipath LUN with LVM I have massive performance problems for all VMs running on that LUN. It looks like the qemu process locks the whole LUN so that no disk writes are performed.
I can see in iotop that nothing happens. As soon as the convert really reads and writes data this issue is resolved and everything is responsive.
Thats an example command I execute to reproduce this issue:
qemu-img
convert -p -n -f raw -O raw /vz/images/999/vm-999-disk-1.raw /dev/nf-lvmstorage/vm-999-disk-0
Can
anybody tell me what is causing this issue? The LUN is very fast and its connected with 10Gbit fiber. When the convert is done any other LUNs also located on the same storage run flawless. On the storage you can also not see any relevant high load.
Thanks
alot in advance!
Greetings,
Thomas
|
Thomas
Schneider | ||
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. | Fon: +49 (0)2236/3936-708 E-Mail: Thomas.Schneider@net-federation.de - www.netfed.de Sürther Hauptstraße 180 B - Köln 50999 |
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