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Re: Backup from huge Maildirs

On Tue, Sep 04, 2007 at 12:30:32AM +0200, mlists wrote:
> my main problem with backing-up Maildirs is that in courier new mails
> are in "new" and when read those same mails are in "cur"
> couple of big mails read result in huge pointless data-transfers.
> anyone know some simple solution for that?
I don't think so.

roberto@miami:~$ dd if=/dev/zero of=test_mail bs=1024 count=102400
102400+0 records in
102400+0 records out
104857600 bytes (105 MB) copied, 1.07652 seconds, 97.4 MB/s
roberto@miami:~$ /usr/bin/time mv test_mail tmp/
0.00user 0.00system 0:00.00elapsed 200%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+244minor)pagefaults 0swaps
roberto@miami:~$ /usr/bin/time mv tmp/test_mail /var/local/
0.00user 0.99system 0:01.35elapsed 73%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (1major+252minor)pagefaults 0swaps

On the above system, /home and /var are on seperate partitions.  Moving
from one directory to another on the same partition is roughly
equivalent (in terms of processing power) to creating a symlink.  Moving
from one partition to another is what takes time and I/O bandwidth.


Roberto C. Sánchez

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