rsync compares all files again and again

Eric Shubert ejs at shubes.net
Tue Oct 18 11:41:12 MDT 2011


On 10/14/2011 02:13 AM, Frank Steiner wrote:
> Hi,
>
> we do a 1:1 backup from our main raid to a backup raid every night with
>
> rsync -a --delete /mnt/raid1/ /mnt/raid2
>
> rsync is 3.09, filesystems are ext3, OS is SLES 11 SP1.
>
> The rsync process takes several hours, even if no file has changed at all.
> Using -vv I see that rsync compares all files every time and that takes
> long for some hundreds of millions of small files.
>
> Can I tell rsync it should not compare files in a directory if the
> directory has not changed, i.e., ctime is the same in source and target?
>
> I.e., when I have a dir x with a subdir y and a file y1 in it, I see:
>
> rsync -avv x z
> created directory z
> delta-transmission disabled for local transfer or --whole-file
> x/
> x/y/
> x/y/y1
>
> on the first run and
>
> rsync -avv x z
> x/y/y1 is uptodate
>
> on every following run. Why does rsync compare y1 again?
>
> I couldn't find a solution in the mailing list or FAQ and when googling.
> I found a mail in this list telling that -a was the culprit and one
> should add -O to fix it, but it doesn't make any difference.
>
> cu,
> Frank
>

Perhaps using the ext3 dirindex option would help?

-- 
-Eric 'shubes'



More information about the rsync mailing list