Dear OpenVZ community, We have a system from IBM (System x3400) with an IBM ServeRAID 8K-I controller on which we are running Debian-Lenny 4.1.2-25. The kernel is openvz-kernel 2.6.26-2-openvz-686. The containers are located on a separate ext3-partition and are mounted like this: /dev/drbd0 on /mnt/hq-drbd-stor01 type ext3 (rw) In particular, we experience a lockup when we try to un-mount and remount the container's partition. The following steps work: vzctl chkpnt 77 vzctl stop 77 /etc/init.d/openvz stop /etc/init.d/openvz start vzctl restore 77 But these don't work: vzctl chkpnt 77 vzctl stop 77 /etc/init.d/openvz stop umount /dev/drbd0 mount /dev/drbd0 /etc/init.d/openvz start vzctl restore 77 The restore produces the lockup. The output until it hangs: Restoring VE ... Starting VE ... VE is mounted undump... Adding IP address(es): 10.20.60.20 Setting CPU units: 1000 Configure meminfo: 65536 Nothing more is displayed after this. The host shows 100% CPU (system-)usage, load goes up to about 10. From our understanding, a container's processes run inside a kernel-process on the host. The container's currently active process (as far as we can tell, it's a different one on any try) takes all the CPU from the host. OpenVZ-version is 036test001. We already tried changing the RAID-controller driver in use from aacraid-1.1.5.2449 to aacraid-1.1.5.2467 but without any luck. Then we tried using USB-disks instead of the dev/drbd0 where the restore worked even after re-mounting, so the issue must lie within the RAID controller. We also tried to run a DRBD device on two USB-disks instead of using ServeRAID attached disks this constellation also works, so we can assume that DRDB is working correctly Is this a known issue? If yes, (how) can it be solved? Is there a way to debug this and provide you and us with more information? Thank you for your time., Maximilian Csuk ipcenter.at
Hello, - let's increase the verbose level of vzctl utility. In /etc/vz/vz.conf please set LOG_LEVEL and VERBOSE variables both to 10. - Quote: OpenVZ-version is 036test001. Sorry, I didn't catch this statement. - Quote: openvz-kernel 2.6.26-2-openvz-686. Do you have a chance to check the stable rhel5-2.6.18 or at least 2.6.18 kernels? I'm not sure that you do, but nevertheless ... http://download.openvz.org/kernel/ - Are there any suspicious messages in dmesg or in logs? - Quote: The host shows 100% CPU (system-)usage, load goes up to about 10. From our understanding, a container's processes run inside a kernel-process on the host. The container's currently active process (as far as we can tell, it's a different one on any try) takes all the CPU from the host. Do you have a chance to get the pid of the process that consumes 100% cpu? What is the output of "/proc/pid/wchan"? - It may be useful to gather alt-sysrq-* outputs: alt-sysrq- 1) "m" - for memory info dump 2) "p" - for registers - several times, please, twice the number of CPUs 3) "a" - for scheduler stat - 3 times 4) "w" - another scheduler info - 3 times 5) "t" - for all processes calltraces. Warning - this is a resource consuming operation. At least - twice.
Thank you very much for the provided information and sorry for delay. I'd recommend you to file a bug into bugzilla. http://bugzilla.openvz.org/