Anyone using iSCSI over DRBD? And a slow internet link perhaps? If yes, you are likely to see connection errors, host resets, and eventually, I/O errors reported, for example:
Jan 7 21:47:09 vmware1 kernel: connection23:0: iscsi: detected conn error (1011) Jan 7 21:47:10 vmware1 kernel: iscsi: host reset succeeded Jan 7 21:47:50 vmware1 kernel: connection23:0: iscsi: detected conn error (1011) Jan 7 21:47:50 vmware1 kernel: iscsi: host reset succeeded Jan 7 21:48:00 vmware1 kernel: sd 22:0:0:1: SCSI error: return code = 0x00020000 Jan 7 21:48:00 vmware1 kernel: end_request: I/O error, dev sdw, sector 1494720 Jan 7 21:48:00 vmware1 kernel: Buffer I/O error on device sdw, logical block 186840 Jan 7 21:48:00 vmware1 kernel: lost page write due to I/O error on sdw This is due to the fact that open-iscsi doesn't seem to like low-speed (but stable) connections to the target. To reproduce: 1) set up a connection with limited speed between the target and the initiator, for example, with openvpn, one would use "--shaper 50000" option to limit the speed to 50 kB/s. 2) login the target to the initiator over this connection (can be also in LAN) 3) start reading and writing... after some time you will be seeing connection errors and host resets followed by I/O errors, possibly data corruption A harder way to reproduce (but somehow more realistic) would be to set up DRBD, start background synchronization at high speed (thus leaving not much bandwidth for normal writes), start reading and writing... I can reproduce it with tgtd and IET, so I guess open-iscsi is to be blamed. Ideas what's wrong and why it fails? -- Tomasz Chmielewski http://wpkg.org --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~----------~----~----~----~------~----~------~--~---
