On Thu, Aug 05, 2010 at 02:42:38AM -0400, Ilia Mirkin wrote: > On Thu, Aug 5, 2010 at 2:25 AM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > a couple of things to see if the hang can be caused faster? Maybe > > trying these different initial conditions: > > Together or independently? independently first - then if that does't work, maybe together? > > - allocate the file with worst case fragmentation by > > writing it backwards in synchronous 4k blocks before > > running the test > > I created the file with > > dd if=/dev/zero of=... bs=1M count=... > > How would I "write backwards"? Like truncate and then seek to the end, > write, seek back, write, etc? Is there a utility that might do it > already? For a 1GB file: $ for i in `seq 256000 1 0`; do > dd if=/dev/zero of=testfile bs=4k count=1 seek=$i conv=notrunc,sync > done Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
