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 wiki.xen.org.
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, 0.6.0.65, 3.2.0-26-generic, x86_64: installed
zfs, 0.6.0.65, 3.2.0-25-generic, x86_64: installed
zfs, 0.6.0.65, 3.2.0-26-generic, x86_64: installed
# zpool status
[sudo] password for kiss:
scan: none requested
NAME STATE READ WRITE CKSUM
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
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.