There is no feature, that has ever existed, that has the capacity to *at runtime* examine all attached disks, and cross reference their SCSI INQUIRY data to a table of available device handlers. That table does not exist, if it did, it would be miserable to maintain.
I checked the udev rules and initramfs scripts from lucid -> precise. We never loaded dh modules automatically. The multipath C code has no facility to modprobe or insmod anything. So the only logical conclusion left is that the module was loaded without your knowledge, which means your configuration as it was would never survive a reboot. If that's not true, and you can reproduce that, I would be interested to see it. However, even if I had the answer, that doesn't completely make up for a complete lack of vendor participation in qualifying your SAN with our operating [1]. We cannot be expected to regression test every SAN in creation and rely on users like you (or vendors) to test and stay engaged. Please contact your vendor expressing support for official Ubuntu support for your SAN multipath-tools is supported by the Community, not Canonical, I volunteer to maintain it. That multipath section in the server guide? I wrote it with the next precise LTS as the deadline, months of effort. multipath as a whole is light years better than it was in lucid, or ever for that matter (many helped). I'm not disagreeing with you that things are missing and there's certainly room for improvement. You've pointed out several issues, like the dialog box,man page etc, that's all good stuff, please file a separate bug for each so we can track them. It's simply a matter of triage and bandwidth, a good multipath bug can soak weeks of time, so configuration polish like you mentioned falls to the way side. However, that sort of work is low hanging fruit, and doesn't require kernel storage engineer with years of experience to accomplish. Contributions are most certainly welcome. FYI, there really isn't a hard spec for multipath.conf, it actually functions a lot like YAML where keywords are globbed, the values integrated and override the defaults. There's no one place in the code where you can go and discover "this is how config works", it's scattered everywhere which makes creating regression tests prohibitive if not practically impossible. 1. The implication is that multipath may have changed so dramatically from 0.4.8 to 0.4.9 that the scsi_dh_rdac driver may not have been as necessary. There's no way we could have caught that on code review, testing was required. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to multipath-tools in Ubuntu. https://bugs.launchpad.net/bugs/1057054 Title: poor performance after upgrade to Precise To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/multipath-tools/+bug/1057054/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
