Re: [zfs-discuss] Heavy write IO for no apparent reason

2013-01-16 Thread Bob Friesenhahn
On Wed, 16 Jan 2013, Peter Wood wrote: Running zpool iostat -v (attachment zpool-IOStat.png) shows 1,22K write operations on the drives and 661 on the ZIL. Compare to the other server (who is in way heavier use then this one) these numbers are extremely high. Any idea how to debug any further

[zfs-discuss] iSCSI access patterns and possible improvements?

2013-01-16 Thread Thomas Nau
Dear all I've a question concerning possible performance tuning for both iSCSI access and replicating a ZVOL through zfs send/receive. We export ZVOLs with the default volblocksize of 8k to a bunch of Citrix Xen Servers through iSCSI. The pool is made of SAS2 disks (11 x 3-way mirrored) plus mirror