On 2012-12-18, at 16:39, "Jason Brooks" <brook...@ohsu.edu> wrote:
> I am currently using lustre 1.8. I am relatively new with lustre. At the > moment, I am trying to move an mds/mgs system from one disk to another. > > I used the version of tar modified by whamcloud in order to dump and restore > the filesytem. I used mkfs.lustre to create a new mds/mgs filesystem on my > /dev/sdc. I then I mounted the old mds at /mnt/mdsold and the new mds at > /mnt/mdsnew using filesystem type "ldiskfs" > > I replicated the filesystem with the following command sequence: > > cd /mnt/mdsold && tar —sparse —xattrs –cf - . | (cd /mnt/mdsnew && tar > —sparse —xattrs –xvpf -) Looks correct. > > However, look at the output of df: > > Filesystem Size Used Avail Use% Mounted on > /dev/sdd 2.3T 7.9G 2.1T 1% /mnt/mdsold > /dev/sdc 815G 3.1G 765G 1% /mnt/mdsnew > > > Now, why would the new filesystem use 3.1 gigabytes when the old one takes up > 7.9G? Perhaps different inode size, or fewer total inodes? > ======================= > > Side note question: I have used the same version of tar to get a file-level > backup of my mds: > > tar —xattrs —sparse –cf - . >sdd.tar > > The file created was 61 gigabytes in size. > > Filesystem Size Used Avail Use% Mounted on > /dev/sdd 2.3T 7.9G 2.1T 1% /mnt/mdsold > > Why is this? Do the attributes take up extra space? Tar is padding each file up to 20kB or something like that. Cheers, Andreas _______________________________________________ Lustre-discuss mailing list Lustre-discuss@lists.lustre.org http://lists.lustre.org/mailman/listinfo/lustre-discuss