From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Dilger Date: Thu, 27 Nov 2008 01:51:52 -0700 Subject: [Lustre-devel] sparse files In-Reply-To: <004701c94fdf$f4255b40$dc7011c0$@com> References: <004701c94fdf$f4255b40$dc7011c0$@com> Message-ID: <20081127085152.GA3186@webber.adilger.int> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org On Nov 26, 2008 15:59 +0000, Eric Barton wrote: > Question for the HSM team. > > Do we need to make the allocation map of a lustre file available > to the HSM agent so it can avoid copying all the holes in sparse > files? There is already an ioctl for this supported by Lustre and ldiskfs that will allow dumping the extent maps if the HSM so chooses. This ioctl is also supported in the upstream Linux kernels, so it will be possible to have generic tools take advantage of it as well. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.