9beta - VMWare iSCSI isses ?

[atakacs]

Hello

I am giving the "official" (a83fe91) beta a go.

I've setup a test rig with a bare metal FreeNas providing iSCSI storage to an ESXi server.

The iSCSI networking is done via a direct cable (no switch / VLAN) with two Intel I350 Gigabit NIC

I created and fairly basic Windows VM and started to play around. Things seemed initially ok but as soon as I got into (relatively) heavy I/O (extracting a zip !) I get errors on the windows machine.

Looking into the ESX logs I see messages such as

Device
t10.FreeBSD_iSCSI_Disk______90b11c5173500-
00_________________ performance has
deteriorated. I/O latency increased from average
value of 5350 microseconds to 964280
microseconds.
warning
07/07/2013 13:52:03
win-cmsvugj19gc.nest.local

Nothing obvious on the FreeNas side, though

Any idea ?

 

[cyberjock]

Nothing obvious? You didn't search for the terms "iscsi latency" did you?

 

[atakacs]

Well what I meant is that I don't see any error / warning on the FreenNAS side (or I'm looking at the wrong place ?). And during those I/O operation memory usage and CPU remains relatively tame (the box has 16Gb RAM and 2 x Intel(R) Xeon(R) CPU E5-2403 @ 1.80GHz so it should be able to handle this load, although I guess I could look into setting up bigger MTU). The disks a 4 WD Red in RAIDZ

Just ran a search in the forum for "iscsi latency" and there are indeed some threads about people asking similar questions (although most of them are actually using NFS) but very little in terms of solutions... but again I might be overlooking the obvious.

Would you by any chance be kind enough to set me straight ? I'm not really worried about performances (yet) but outright I/O errors where not expected...

 

[jgreco]

search for references to bug 1531, this is usually a tuning issue of some sort.