Lustre announce - Sep 2007 - WARNING: data corruption for > 2TB OSTs on 32-bit systems

Bug 13627 was recently discovered with a test Lustre installation that
resulted in silent data corruption.  If a large (more than 2TB) OST is
set up on a 32-bit kernel the disk offset for the data IO (though not
the filesystem metadata) would be wrapped at 2TB and possibly overwrite
existing data in the filesystem.

This problem is not present on 64-bit kernels or on OSTs that are smaller
than 2TB in size.  Note that the word size of the kernel is important,
not the CPU it is running on, so a 32-bit (i386, i686) kernel on a 64-bit
CPU (x86_64) with larger than 2TB OSTs is affected by this problem.

Since this problem is always present, it would normally have shown itself
right after installation, and virtually all new Lustre installations
(which are likely to have larger OSTs) are using 64-bit kernels for
improved performance and large memory management.

This problem will be fixed in 1.4.12, and 1.6.3 Lustre releases.
Until these are released, you should not create OSTs larger than 2TB
on 32-bit kernels.  If you believe your existing filesystem is affected
by this issue, please contact CFS support (http://bugzilla.lustre.org).
There are no known instances of this problem on production systems.

 -- The Lustre Team --