[Lustre-discuss] MDT backup

[Kalpak Shah]

On Tue, 2009-02-03 at 10:57 -0700, Nathan Dauchy wrote:
> Brian J. Murrell wrote:
> > On Mon, 2009-01-19 at 22:46 -0600, Alex Kulyavtsev wrote:
> >> Hi,
> >> what is the right way to backup MDT ?
> > 
> > I think this is covered in the operations manual.
> > 
> 
> The manual does indeed cover backups:
> http://manual.lustre.org/manual/LustreManual16_HTML/BackupAndRestore.html
> 
> It includes this step:
> 
> >  3. Back up the EAs, run:
> > getfattr -R -d -m '.*' -P . > ea.bak
> > 
> 
> Is that necessary for newer versions of tar that support the "-xattrs"
> option?  From the man page (I have GNU tar 1.15.1):
> 
> --xattrs	this  option  causes  tar  to  store  each  file's
> 		extended  attributes in the archive. This option also
> 		enables --acls and--selinux if they haven't been
> 		set already, due to the fact that the data for those
> 		are stored in special xattrs.
> 
> Also, AFAIK, cpio will archive extended attributes as well.
> 
> Is either 'tar --xattrs' or 'cpio' sufficient for capturing all the
> Lustre MDT information?  Would that eliminate the need for the
> 'getfattr' step, and cut the time for backup almost in half by requiring
> only one pass through the filesystem?

The "tar" package shipped with distros cannot recognize "lustre."
extended attributes and hence cannot be used for Lustre backups.

You will need to use Lustre patched tar available for download at
http://downloads.lustre.org/public/tools/lustre-tar/


Thanks,
Kalpak