ZFS Linux under BHyVe+ZVOL delete files very slow

A

abishai

I have no experience to run virtualized systems, but I setup ZoneMinder surveillance system on virtual CentOS host. The load pattern is millions small jpg files, linux put on ext2.
24x250Kb jpgs is written per second.

ZFS volume is 2 mirrored half-dead 1Tb disks (they have SMART so bad, that looks like raw value counters turns over every week on some entries).
http://pastebin.com/MTMkfqcw
http://pastebin.com/XQENA8wh

Data write is good, but deleting is so slow, that cameras fills volume faster rm works. I suspect that ext2 filesystem is not very good to keep small files, but I can be wrong. Or maybe BHyVE or ZFS syncs every file deleted.

Will SSD L2ARC/ZIL help on such patterns?
 
BHyVe on ZFS honestly respect cache syncs sent by virtual machine. If guest sends many flushed and you don't have SLOG device in your pool, then performance can predictably be low. If data are not highly critical, you may try to set sync=disabled on ZVOL and see what happen with performance.
 
Didn't know about this option. Looks like a solution, but I have to wait my volume fills up again.
 
You must log in or register to reply here.
Back
Top