Hello and thanks in advance for reading, We've been having serious read performance issues with Open-iSCSI.
I'll list the specs of our setup first: The SAN: - Dual-Core Xeon with 2GB RAM, running Microsoft Windows Storage Server 2003 R2 - 5TB storage, sliced into two 1.5TB and one 2.0TB partition. - Dual Broadcom NC324i NICs - 1Gbit uplink to switch, using the first Broadcom card. The client machine experiencing the problem: - Quad-Core Opteron with 8GB, running Gentoo Linux, kernel 2.6.24- gentoo-r5 - It uses the 2TB iSCSI Target, formatted as xfs and used as backup/ restore for local storage - Dual Broadcom BCM5708 NICs - Intel 82545GM fibre NIC - Open-ISCSI version 2.0-870-rc1 (latest version) - 1Gbit uplink to switch, using the Intel NIC (fibre). The switch: - Cisco 3750G, 24xCopper Gigabit switch with three fibre-modules The problem we're experiencing is this: When we copy a file from the local disk array to the iSCSI target, the write performance is amazing: we max out the gigabit link immediately (>100MB/sec writes easily). When we copy a file from the iSCSI target to the local disk array however, performance is absolutely *dreadful*: 1-4MB/sec. This also completely floods the client machine with I/O requests (as seen by running 'htop'): the load jumps to ~6-8 and it becomes very slow and almost unresponsive to commands. What I've tried to rectify the problem, is what I could find online so far: - Enable Flow Control on the NICs: no change in speed. - Change to the copper NIC on the client machine: no change in speed. - Use different read-ahead settings on the SCSI device 'blockdev -- setra ...' (4096-65536). This only initially solves the problem: we get a short burst of good speed, and then it dies again. It kills the random reads/write speeds, however. - Different programs make no difference: the problem occurs with bonnie ++, cp, scp, mv, etc. Can anyone help me figure this out, or point me in the right direction? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to email@example.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~----------~----~----~----~------~----~------~--~---