On 02/24/2012 01:50 AM, Sabuj Pattanayek wrote: > This seems to be a bug in XFS as Joe pointed out : > > http://oss.sgi.com/archives/xfs/2011-06/msg00233.html This was in a different context though. Are your files sparse by default? > http://stackoverflow.com/questions/6940516/create-sparse-file-with-alternate-data-and-hole-on-ext3-and-xfs > > It seems to be there in XFS available natively in RHEL6 and RHEL5 Yes. > > On Thu, Feb 23, 2012 at 5:12 PM, Sabuj Pattanayek<sabujp at gmail.com> wrote: >> Hi, >> >> I've been migrating data from an old striped 3.0.x gluster install to >> a 3.3 beta install. I copied all the data to a regular XFS partition >> (4K blocksize) from the old gluster striped volume and it totaled >> 9.2TB. With the old setup I used the following option in a "volume >> stripe" block in the configuration file in a client : >> >> volume stripe >> type cluster/stripe >> option block-size 2MB >> subvolumes .... >> end-volume >> >> IIRC, the data was using up about the same space on the old striped >> volume (9.2T) . While copying the data back to the new v3.3 striped >> gluster volume on the same 5 servers/same brick filesystems (XFS w/4K >> blocksize), I noticed that the amount stored on disk increased by 5x 512B blocks are 1/8 the size of the 4096B blocks, so a scheme where 512B blocks are naively replaced by 4096B blocks should net an 8x space change if that is the issue. . >> >> Currently if I do a du -sh on the gluster fuse mount of the new >> striped volume I get 4.3TB (I haven't finished copying all 9.2TB of >> data over, stopped it prematurely because it's going to use up all the >> physical disk it seems if I let it keep going). However, if I do a du >> -sh at the filesystem / brick level on each of the 5 directories on >> the 5 servers that store the striped data, it shows that each one is >> storing 4.1TB. So basically, 4.3TB of data from a 4K block size FS >> took up 20.5TB of storage on a 128KB block size striped gluster So you have 5 servers, each storing a portion of a stripe. You get a 5x change in allocation? This sounds less like an xfs issue and more like a gluster allocation issue. I've not looked lately at the stripe code, but it may allocate the same space on each node, using the access pattern for performance. >> volume. What is the correlation between the " option block-size" >> setting on client configs in cluster/stripe blocks in 3.0.x vs the >> cluster.stripe-block-size parameter in 3.3? If these settings are >> talking about what I think they mean, then basically a file that is 1M >> in size would be written out to the stripe in 128KB chunks across N >> servers, i.e. 128/N KB of data per brick? What happens when the stripe >> block size isn't evenly divisible by N (e.g. 128/5 = 25.6). If the old >> block-size and new stripe-block-size options are describing the same >> thing, then wouldn't a 2MB block size from the old config cause more >> storage to be used up vs a 128KB block size? >> >> Thanks, >> Sabuj > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://gluster.org/cgi-bin/mailman/listinfo/gluster-users -- Joseph Landman, Ph.D Founder and CEO Scalable Informatics Inc. email: landman at scalableinformatics.com web : http://scalableinformatics.com http://scalableinformatics.com/sicluster phone: +1 734 786 8423 x121 fax : +1 866 888 3112 cell : +1 734 612 4615
