Am 03.05.2011 13:08, schrieb Chris Mason: >> defragging btrfs does not seem to work for me. I have run the filefrag >> command over the whole fs and (manually) tried to defrag a few heavily >> fragmented files, but I don't get it to work (it still has the same >> number of extends and they are horrently uncorrelated) >> >> root@schleppi:~# filefrag >> /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.4/cc1 >> /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.4/cc1: 72 extents found >> root@schleppi:~# btrfs filesystem defrag >> /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.4/cc1 >> root@schleppi:~# filefrag >> /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.4/cc1 >> /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.4/cc1: 72 extents found >> >> I'm using Ubuntu Natty (2.6.38.4) and tried both btrfs-tools from Natty >> (201006xx) and from Debian experimental (git from 20101101). Both show >> the same symptoms. I don't think fragmentation is bad on this box (due >> to having an SSD), but my system at home is getting dog slow and I'd >> like to try that when I come home end of the week. > > Do you have compression on?
Yes. lzo to be exact. > The file the defrag ioctl works is that it schedules things for defrag > but doesn't force out the IO immediately unless you use -f. > > So, to test the result of the defrag, you need to either wait a bit or > run sync. Did so, no change. See my reply to cwillu for the data. I usually mount my / without any compression option and did "mount -o remount,compress=lzo /" before. I cannot reboot at the moment and I did not find any option to disable compression again. There does not seem to be a "nocompress" or "compress=[none|off]" option. Is this correct? Bernhard -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
