I have some good news. I'm unable to reproduce the bug with the -proposed Xenial kernel, which is v4.3 based. I will continue to test this kernel for some time to ensure it really doesn't exhibit the bug. If needed, I'll continue to drive up the IO load. If it does not exhibit the bug, I can perform a "Reverse" kernel bisect to find the exact patch that fixes things.
Some other good news is that all of the patches in the 4.3 kernel have been requested for Wily in bug 1519917. A Wily test kernel with all those commits has been built and currently undergoing testing. I'll also review all the HyperV related patches in the 4.3 kernel to see if any stick out as a possible fix for this bug. I should have an update shortly. If anyone is interested in testing the -proposed Xenial kernel, it can be downloaded from: https://launchpad.net/ubuntu/+source/linux/4.3.0-1.10/+build/8370648 >From that page you would need to install the following four .debs: linux-image-4.3.0-1-generic 4.3.0-1.10 linux-image-extra-4.3.0-1-generic 4.3.0-1.10 linux-cloud-tools-4.3.0-1 4.3.0-1.10 linux-cloud-tools-4.3.0-1-generic 4.3.0-1.10 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1470250 Title: [Hyper-V] Ubuntu 14.04.2 LTS Generation 2 SCSI Errors on VSS Based Backups Status in linux package in Ubuntu: In Progress Status in linux source package in Trusty: In Progress Status in linux source package in Utopic: In Progress Status in linux source package in Vivid: In Progress Status in linux source package in Wily: In Progress Bug description: Customers have reported running various versions of Ubuntu 14.04.2 LTS on Generation 2 Hyper-V Hosts. On a random Basis, the file system will be mounted Read-Only due to a "disk error" (which really isn't the case here). As a result, they must reboot the Ubuntu guest to get the file system to mount RW again. The Error seen are the following: Apr 30 00:02:01 balticnetworkstraining kernel: [640153.968142] storvsc: Sense Key : Unit Attention [current] Apr 30 00:02:01 balticnetworkstraining kernel: [640153.968145] storvsc: Add. Sense: Changed operating definition Apr 30 00:02:01 balticnetworkstraining kernel: [640153.968161] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automatically adjust these parameters. Apr 30 01:23:26 balticnetworkstraining kernel: [645039.584164] hv_storvsc vmbus_0_4: cmd 0x2a scsi status 0x2 srb status 0x82 Apr 30 01:23:26 balticnetworkstraining kernel: [645039.584178] hv_storvsc vmbus_0_4: stor pkt ffff88006eb6c700 autosense data valid - len 18 Apr 30 01:23:26 balticnetworkstraining kernel: [645039.584180] storvsc: Sense Key : Unit Attention [current] Apr 30 01:23:26 balticnetworkstraining kernel: [645039.584183] storvsc: Add. Sense: Changed operating definition Apr 30 01:23:26 balticnetworkstraining kernel: [645039.584198] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automatically adjust these parameters. This relates to the VSS "Windows Server Backup" process that kicks off at midnight on the host and finishes an hour and half later. Yes, we do have hv_vss_daemon and hv_kvp_daemon running for the correct kernel version we have. We're currently running kernel version 3.13.0-49-generic #83 on one system and 3.16.0-34-generic #37 on the other. -- We see the same errors on both. As a result, we've been hesitant to drop any more ubuntu guests on our 2012R2 hyper-v system because of this. We can stop the backup process and all is good, but we need nightly backups to image all of our VM's. All the windows guests have no issues of course. We also have some CentOS based guests running without issues from what we've seen. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470250/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
