Results 1 to 2 of 2

Thread: XEN and ZFS hangs

  1. #1
    Join Date
    Oct 2007

    XEN and ZFS hangs

    I try to build a XEN host with native ZFS storage. Native ZFS installs successfully, and created raidz pool fine. After that installed the XCP-XAPI followed the instructions at

    The XEN installing fine, but after reboot any operations on the ZFS mount hangs/freezing. There are no syslog entries, errors. The only thing is 4 process (txg_sync, z_null_iss/0, zfs and txg_quiesce), eatin all CPU power.

    I find some articles, that suggest to install the latest daily ZFS build, but it seems the stable and the daily ppa are the same.

    With the standard (non-XEN) kernel ZFS is working fine.

    It is happend with anyone else? How can I find mor information about this problem?

    # uname -a
    Kernel: Linux server 3.2.0-26-generic #41-Ubuntu SMP Thu Jun 14 17:49:24 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

    # dkms status
    blktap, 2.0.91, 3.2.0-26-generic, x86_64: installed
    openvswitch, 1.4.0, 3.2.0-25-generic, x86_64: installed
    openvswitch, 1.4.0, 3.2.0-26-generic, x86_64: installed
    spl,, 3.2.0-26-generic, x86_64: installed
    zfs,, 3.2.0-25-generic, x86_64: installed
    zfs,, 3.2.0-26-generic, x86_64: installed

    # zpool status
    [sudo] password for kiss:
    pool: data
    state: ONLINE
    scan: none requested

    data ONLINE 0 0 0
    raidz1-0 ONLINE 0 0 0
    scsi-SATA_SAMSUNG_HD204UIS2H7J90B614909 ONLINE 0 0 0
    scsi-SATA_SAMSUNG_HD204UIS2H7J90B614910 ONLINE 0 0 0
    scsi-SATA_SAMSUNG_HD204UIS2H7J90B614957 ONLINE 0 0 0

    errors: No known data errors

  2. #2
    Join Date
    Jan 2008

    Re: XEN and ZFS hangs

    I'm having the same issue (same 3 processes and IO hang) on Debian Wheezy, 3.2 kernel under Xen 4.2.

    Did you ever figure anything out?

    I performed an additional test with zfs_arc_max set to 512MB and it remained slow under Xen. On bare metal and with same zfs_arc_max setting the performance is fast.
    Last edited by dblade; October 12th, 2012 at 01:24 AM.


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts