Does previously existing data on disk affect fragmentation? On Tue, Aug 25, 2015 at 1:32 PM, Shrinand Javadekar <shrinand@xxxxxxxxxxxxxx> wrote: > Hi, > > I have 23 disks formatted with XFS on a single server. The workload is > Openstack Swift. See this email from a few months ago about the > details: > > http://oss.sgi.com/archives/xfs/2015-06/msg00108.html > > I am observing some strange behavior and would like to get some > feedback about why this is happening. > > I formatted the disks with xfs (mkfs.xfs) and deployed Openstack Swift > on it. Writing 100GB of data into Swift in batches of 20GB each gave > us the following throughput: > > 20 GB: 93MB/s > 40 GB: 65MB/s > 60 GB: 52MB/s > 80 GB: 50MB/s > 100 GB: 48MB/s > > I then re-formatted the disks with mkfs.xfs -f and ran the experiment > again. This time I got the following throughput: > > 20 GB: 118MB/s > 40 GB: 95MB/s > 60 GB: 74MB/s > 80 GB: 68MB/s > 100 GB: 63MB/s > > I've seen similar results twice. > > Any ideas why this might be happening? > > Thanks in advance. > -Shri _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
