On Thu, Apr 24, 2008 at 5:10 PM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote: > Abhishek Rai wrote: > > This patch modifies the block allocation strategy in ext3 in order to > > improve fsck performance. This was initially sent out as a patch for > > ext2, but given the lack of ongoing development on ext2, I have > > crossported it to ext3 instead. Slow fsck is not a serious problem on > > ext3 due to journaling, but once in a while users do need to run full > > fsck on their ext3 file systems. This can be due to several reasons: > > (1) bad disk, bad crash, etc, (2) bug in jbd/ext3, and (3) every few > > reboots, it's good to run fsck anyway. This patch will help reduce > > full fsck time for ext3. I've seen 50-65% reduction in fsck time when > > using this patch on a near-full file system. With some fsck > > optimizations, this figure becomes 80%. > > For what it's worth, this speeds large file removals, too: > > http://people.redhat.com/esandeen/rm_test/ext3_metacluster_rm.png > http://people.redhat.com/esandeen/rm_test/ext3_rm.png > > That's 22s vs. 73s for a 56G file on a fresh 100G filesystem, removed > after a fresh remount (cold cache). > > If I actually preload all of the indirect blocks (I used filefrag): > > http://people.redhat.com/esandeen/rm_test/ext3_preload_rm.png > > it comes in at 6 seconds... > > For comparison, stock ext4 from 2.6.25 clocks in at 6s, and xfs is > basically instantaneous. (btrfs default is 6s, and btrfs with no data > checksumming is on par with xfs). Abhishek, Given the favorable results Eric posted and the prospect for significantly reduced fsck times with your patch; what is the status of your patch? Do you have an updated version of your patch for ext3 that should get further testing? please advise, thanks. Mike -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
