The default stripe count and stripe size on the Pleiades Lustre filesystems will be changed on Thursday, January 13, 2011, 8:00 a.m. Pacific Time.

For Whom: All Pleiades Users with Data on /nobackupp[10-60]

What: Changes to the Default Stripe Count and Stripe Size

When: 01/13/2011, 8:00 am Pacific Time

Impact to users: The default stripe count and stripe size on the Pleiades Lustre filesystems will be changed. The default stripe count will be set to 1 and the default stripe size to 4 MB. This change will result in fewer stat calls and, over time, improve the slow 'ls -l' issue. It is important to be aware that if you need to create large files, you will need to set the stripe count on the directory or file, by using the 'lfs setstripe' command.

Information on how to set the Lustre stripe count is available in our Lustre documentation.

A modified gnu tar command, /usr/local/bin/mtar, has been developed that is Lustre stripe aware and will create a tar file or extract files with a sufficiently large stripe count to hold the file. We recommend using mtar in place of tar whenever the tar archive or extracted files will be written to Lustre. The mtar command works just like the normal tar command except as explained above.

If you have any problems after the change, please send email to support@nas.nasa.gov or call 1-800-331-8737 or 1-650-604-4444.