Reinis, ls commands on modern GNU/Linux systems run xattr calls on each entry for ACL purposes. This can turn out to be pretty expensive in terms of performance. If you just run /bin/ls, or ls after 'unalias ls', you should observe that the performance improves quite a bit, either because both stat() and xattr calls were skipped, or because just stat() calls were skipped. avati 2008/4/7, Reinis Rozitis <roze@xxxxxxx>: > > Hello, > there have been some threads in the past about 'ls' being slow on large > file > directories but my question is more regarding documentation: > > According to http://www.gluster.org/docs/index.php/GlusterFS_FAQ - "Just > doing "ls" doesn't trigger stat call. It should be fast as this is called > only on the namespace child." > > But actually on our system/setup (where namespace resides on seperate > partition (c0d0) and the storage bricks are different pairs of disks > (c1d0-c2d6) mounted together with unify) we see that after doing 'ls' a > sequence starts which reads every storage brick (and not only namespace). > > > In iostat it looks something like this (I hope the spacing won't break): > > avg-cpu: %user %nice %system %iowait %steal %idle > 0.00 0.00 0.50 0.00 0.00 99.50 > > Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn > cciss/c0d0 0.00 0.00 0.00 0 0 > cciss/c1d0 0.00 0.00 0.00 0 0 > cciss/c1d1 0.00 0.00 0.00 0 0 > cciss/c1d2 0.00 0.00 0.00 0 0 > cciss/c1d3 189.00 3008.00 0.00 3008 0 > cciss/c1d4 0.00 0.00 0.00 0 0 > cciss/c1d5 0.00 0.00 0.00 0 0 > cciss/c1d6 0.00 0.00 0.00 0 0 > cciss/c1d7 0.00 0.00 0.00 0 0 > cciss/c1d8 0.00 0.00 0.00 0 0 > cciss/c1d9 0.00 0.00 0.00 0 0 > cciss/c2d0 0.00 0.00 0.00 0 0 > cciss/c2d1 0.00 0.00 0.00 0 0 > cciss/c2d2 0.00 0.00 0.00 0 0 > cciss/c2d3 0.00 0.00 0.00 0 0 > cciss/c2d4 0.00 0.00 0.00 0 0 > cciss/c2d5 0.00 0.00 0.00 0 0 > cciss/c2d6 0.00 0.00 0.00 0 0 > > > There is only one partition being read at time when it finishes it > switches > to the next. Sometimes the loop goes even 2 or 3 times before the > directory/file listing is returned. So it takes pretty long after the > mounted partition becomes responsive. > > I wonder is it supposed to be so or the 'ls' from OpenSuse "breaks" the > whole thing (because it adds some commandline params on its own - full > command looks like 'ls -N --color=tty -T 0 -1') > > wbr > Reinis Rozitis > > > > _______________________________________________ > Gluster-devel mailing list > Gluster-devel@xxxxxxxxxx > http://lists.nongnu.org/mailman/listinfo/gluster-devel > -- If I traveled to the end of the rainbow As Dame Fortune did intend, Murphy would be there to tell me The pot's at the other end.
