On 10/07/2013 01:48 PM, Ned Bass wrote: > On Mon, Oct 07, 2013 at 06:09:21AM -0400, Anjana Kar wrote: >> Is it possible to configure the MDT as ldiskfs and the OSTs with zfs >> in lustre 2.4? The server is running a lustre kernel on a Centos 6.4 >> system, has both lustre-osd-ldiskfs and lustre-osd-zfs rpms installed. >> The MDT is up as ldiskfs, but get an error trying to configure the ost: >> >> mkfs.lustre --fsname=lustrefs --reformat --ost --backfstype=zfs ..... >> >> mkfs.lustre FATAL: unable to prepare backend (22) >> mkfs.lustre: exiting with 22 (Invalid argument) > I suspect that the mkfs.lustre error is unrelated to the presence of an > ldiskfs MDT. We need to see the complete command line parameters and > output to help you diagnose that problem. It's often helpful to try > creating the pool and dataset "by hand" with zpool create and zfs > create, using the same names and devices. It may reveal the problem > with an error message that is masked by mkfs.lustre. Also check dmesg > to see if there was an error loading the ZFS module stack. > > Having said all that, as Andreas said, you may run into other problems > running the ZFS and ldiskfs OSDs concurrently on the same node. Using > separate MDS and OSS nodes is more likely to work, but this > configuration has not seen much testing. So please report on your > experience if you go this route. > > Thanks, > Ned
Here is the exact command used to create a raidz2 pool with 8+2 drives, followed by the error messages: mkfs.lustre --fsname=cajalfs --reformat --ost --backfstype=zfs --index=0 --mgsnode=10.10.101.171@o2ib lustre-ost0/ost0 raidz2 /dev/sda /dev/sdc /dev/sde /dev/sdg /dev/sdi /dev/sdk /dev/sdm /dev/sdo /dev/sdq /dev/sds mkfs.lustre FATAL: Invalid filesystem name /dev/sds mkfs.lustre FATAL: unable to prepare backend (22) mkfs.lustre: exiting with 22 (Invalid argument) dmesg shows ZFS: Loaded module v0.6.2-1, ZFS pool version 5000, ZFS filesystem version 5 Any suggestions on creating the pool separately? Thanks, -Anjana _______________________________________________ Lustre-discuss mailing list Lustre-discuss@lists.lustre.org http://lists.lustre.org/mailman/listinfo/lustre-discuss