Appaling iSCSI performance
807557Dec 5 2008 — edited Dec 9 2008Hi all,
I have a severe perfromance issue with iSCSI targets hosted on Solaris 10 - and don't know how to try and improve/diagnose it.
The setup is a solaris server with a zpool on external storage.
To test I created an 8gb block device on the zfs and exported it as iSCSI.
From a windows desktop machine I get a write perfromance of 70kB/s (yes kilo bytes or 560kbit/s)
Creating a ZFS share on the same pool and transfering the same file via cifs results in write performance of 10MB/s (mega bytes or 80Mbit/s) which given the NIC is a 100Mb nic on the desktop is pretty close to ideal.
This was a quick test - I have XEN VMs whose discs are stored on the Solaris server also - and the speed of them is just terrible.
(I don't think its always that bad but after the server has been on for a while it gets bad).
The XEN vms are attached via a gigabit switch directly to the solaris box.
I have no idea about how to try and track this issue down - any pointers greatfully received