Hi htere, I am using the open-iscsi initiator to access a storage back end for my Xen based virtualization infrastructure. Since The current 3.0.x Linux kernel finally has everything that I need to run the host system (Dom0) without any additional patches I thought I'd give it a try and see if I can replace the 2.6.32 hosts that cause a lot of trouble when mixing Xen + iSCSI + multipath.
This is raw "dd" throughput for reading ~30GB from an iSCSI storage via a dedicated 1GB Ethernet link. 2.6.32 : 102 MB/s 2.6.38 : 100 MB/s 2.6.39 : 44 MB/s 3.0.1 : 43 MB/s Seems like between 2.6.38 and 2.6.39 the iSCSI performance got pretty much thrown out the window ... If I were into into conspiracy theories I'd suspect that the Core- iSCSI guys are out to prove the superior performance of their initiator by slowing down the open-iSCSI competitor. ;-) (See http://linux-iscsi.org/wiki/Core-iSCSI#Performance ) I tested with Debian Squeeze on bare metal to remove Xen from the equation and I tested without multipath to avoid those complications too. Kernel 2.6.32 is the default Squeeze kernel, 2.6.38 and 2.6.39 were from squeeze-backports and 3.0.1 was built from the vanilla kernel sources using make-kpkg. The storage is a Dell / Equallogic PS4000. Please drop me a line if you can confirm or refute those findings. On the positive side I have to say that the 3.0.1 kernel is much more stable in my Xen + iSCSI + multipath setup. (Though I havn't yet tested it with the load that I have on the 2.6.32 machine.) -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/open-iscsi?hl=en.
