Hello,
I''m trying to use mod3 ckds which are already RAID10 protection. (most
of the doc I''m looking at uses fba instead of ckd, so I didn''t
know if this was a limitation)
I''m addressing the head device and able to use these devices with no
problem as ext3. I''ve been reading that cache may remember that it
used to be ext3, so I detached and reattached, but get the same result when
trying to mount after formatting.
I use the following to make the file system after I''ve attached, varied
online, formated and partitioned (also tried without the journaling switch).
mke2fs -j -t btrfs /dev/dasdbj1
Then the mount command:
mount -t btrfs /dev/dasdbj1 /home/sdasd/d01
mount: /dev/dasdbj1: can''t read superblock
Can you please give me some direction?Thanks,
Kathy Hodge
EMC²
Mainframe Software QA
Phone: 1-508-293-6121 x76121
Cell: 1-303 -887-9292
Email: kathleen.hodge@emc.com
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On Thu, Jun 02, 2011 at 03:45:07PM -0400, kathleen.hodge@emc.com wrote:> Hello, > I''m trying to use mod3 ckds which are already RAID10 protection. (most of the doc I''m looking at uses fba instead of ckd, so I didn''t know if this was a limitation) > I''m addressing the head device and able to use these devices with no problem as ext3. I''ve been reading that cache may remember that it used to be ext3, so I detached and reattached, but get the same result when trying to mount after formatting. > > I use the following to make the file system after I''ve attached, varied online, formated and partitioned (also tried without the journaling switch). > mke2fs -j -t btrfs /dev/dasdbj1Quoting the man page for that command: "mke2fs is used to create an ext2, ext3, or ext4 filesystem, [...]" The -t option specifies which of ext2, ext3, and ext4 to create. I''m surprised it did anything at all given a type of "btrfs"... You probably wanted mkfs.btrfs instead: # mkfs.btrfs -d single -m single /dev/dasdbj1> Then the mount command: > mount -t btrfs /dev/dasdbj1 /home/sdasd/d01 > mount: /dev/dasdbj1: can''t read superblockIf it created an ext2/3/4 filesystem, I''m not entirely surprised that it can''t find a btrfs superblock there. :) Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- We teach people management skills by examining characters in --- Shakespeare. You could look at Claudius''s crisis management techniques, for example.
Hi, Kathleen, On Thu, Jun 02, 2011 at 04:20:55PM -0400, kathleen.hodge@emc.com wrote:> Hi Hugo, I don''t seem to have mkfs.btrfs. Here is the Red Hat 6.0 version I''m running, should it be included? > > Linux LN164088.LSS.EMC.COM 2.6.32-71.el6.s390x #1 SMP Wed Sep 1 01:38:33 EDT 2010 s390x s390x s390x GNU/LinuxOK, first -- kernel 2.6.32 is *massively* old in btrfs terms. There are a whole bunch of pretty serious bugs that have been fixed between then and now. You should really be running a kernel no earlier than 2.6.38: version 2.6.39 is preferable. You should also be using the latest btrfs-progs from the git repository: $ git clone git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs-unstable.git $ git co tmp $ make $ sudo make install (You may need the libuuid-devel package to get this to build. There''s also a problem with the most recent gcc, but that probably won''t apply to you; it''s easily dealt with if you do hit it). Once you''ve made and installed btrfs-progs, you will have mkfs.btrfs, and the btrfs tool, which is used for managing your filesystem. You should also ensure that you''re keeping good and regular backups of the data in your filesystem, and be prepared to use them -- btrfs is still considered experimental, and if things go wrong, the fastest way at the moment to get your data back is often to restore from backups. Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- "I don''t like the look of it, I tell you." "Well, stop --- looking at it, then."