So I'm reporting my current further findings here in case somebody else than me stumbles upon this bug report in search of help.
I'll not create a new bug report as of now, since I'm still researching the problem and I think there's no point in opening a new bug report if it'll turn out to be invalid anyway. So to the point: in my case the problem has been: 8 05:02:51 foo kernel: [987432.148305] device-mapper: snapshots: Invalidating snapshot: Unable to allocate exception. after that umount goes berzerk: Nov 8 05:02:51 foo kernel: [987432.163602] Buffer I/O error on device dm-11, logical block 11985789 Nov 8 05:02:51 foo kernel: [987432.163638] Buffer I/O error on device dm-11, logical block 11985790 ... Nov 8 05:02:51 foo kernel: [987432.299393] EXT4-fs warning (device loop0): __ext4_read_dirblock:901: error reading directory block (ino 3539872, block 0) Nov 8 05:02:57 foo kernel: [987437.577541] quiet_error: 4396 callbacks suppressed Nov 8 05:02:57 foo kernel: [987437.577547] Buffer I/O error on device dm-11, logical block 12622895 Nov 8 05:02:57 foo kernel: [987437.577609] lost page write due to I/O error on dm-11 and now umount is hanging there with 100% CPU usage with no possibility to `kill` it. So one problem here is that the `lvsnapshot` is running out of `exception` space. Thus I should either allow the snapshot to be autoextended or to increase the `-L`size I have given it. But even so, umount shouldn't get stuck on the ext4 FS. Since I was `umount`ing without `-f` I will try that today and see what happens and report back here hopefully. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1115753 Title: Umount of Multiple LVM Snapshots Causes 'soft lockup CPU#0 stuck for' To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1115753/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
