On 4 May 2010, at 23:25, John G. Heim wrote: > I have a Poweredge SE1435 which seems to be very slow and i noticed > something odd... I can create a large file with dd faster than I can > delete > it. > > # date; dd if=/dev/zero of=zero.txt bs=1024 count=1000000; date; rm > zero.txt; date > Tue May 4 16:59:21 CDT 2010 > 1000000+0 records in > 1000000+0 records out > 1024000000 bytes (1.0 GB) copied, 11.7291 s, 87.3 MB/s > Tue May 4 16:59:33 CDT 2010 > Tue May 4 17:00:09 CDT 2010 > > It took 12 seconds to create the file and 33 seconds to rm it. Why > would > that be?
Ou of curiosity, is there a reason you didn't do `time dd if=/dev/zero of=zero.txt bs=1024 count=1000000 && time rm zero.txt` ? > This machine is serving as a print server, debian package mirror, > and a > mmysql database server. I am not sure what kind of info you might > need to > help me. But for starters, I'm running debian lenny with a 2.6.30 > kernel. > The file system is ext3. I'm not saying this is wholly the reason, but ext3 is notoriously slow at deletions. MythTV even had (has?) a special function to accommodate ext3, otherwise the deletion of a movie (which might well be several gigs in size) would lock the system solid for a minute or two, halting playback and corrupting any recordings in progress. See the "Filesystems" section at [1]. You may not be in a position to do this, but it would be interesting to upgrade the filesystem to ext4 with extents, then try again. I have found - only in typical use, no scientific testing - the delete performance between ext3 and ext4 to be *very* obvious. Stroller. [1] http://www.mythtv.org/docs/mythtv-HOWTO-3.html _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
