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Re: rsync 10 times slower in Etch than in Sarge!

Rodolfo Medina <rodolfo.medina@gmail.com> writes:

>>> I do my daily backup with the following command:
>>>  $ rsync -vr --delete Mail News /mnt/sda
>>> (where `sda' is the pendrive), and I've calculated that in my new Debian
>>> Etch system the process is about 10 times slower than it was in Sarge!
>>> It is the same with both my desktop PC and my laptop.  In /etc/fstab I
>>> have the following entry:
>>>  /dev/sda        /mnt/sda 	vfat    sync,rw,user,noauto  0       0
>>> .  The backup that would take only a few minutes now takes almost one
>>> hour!  Can anybody please explain this strange phenomena?

Sven Joachim <svenjoac@gmx.de> writes:

>> IIRC it's an issue with vfat file systems and the "sync" mount option in
>> 2.6 kernels.  I noticed the same phenomenon when I switched from 2.4 to
>> 2.6;
>> the solution is not to use the "sync" option, that also increases
>> your drive's lifetime.


> I put the `sync' option just to avoid drive corruption.  If it is
> necessary to toggle it off, how can I be sure the process is terminated
> before I unmount the drive?

"Nelson Castillo" <nelsoneci@gmail.com> writes:

> This was discussed sometime ago in this list (someone wanted to
> be able to remove the USB drive anytime). Using sync is not a good
> idea with the USB pendrive.
> Check this thread:
> http://marc.info/?t=117925038400003&r=1&w=2

Sven Joachim <svenjoac@gmx.de> writes:

>> You may want to add "sync" as the last command in
>> your backup script do avoid data loss.

"Nelson Castillo" <nelsoneci@gmail.com> writes:

> You use the same rsync command. You execute sync _after_
> the rsync command.

"Douglas A. Tutty" <dtutty@porchlight.ca> writes:

> Why issue a 'sync' instead of just unmounting and waiting until the
> thing stops flashing?

Ken Irving <fnkci@uaf.edu> writes:

> sync blocks, so you can tell from the command line when the job is done.
> I guess this thread took a turn to USB drives, which would presumably
> be local, but the rsync operation might be on a remote system where the
> lights aren't visible.  For that matter, umount also blocks...  I often
> use sync before umount, but I suppose it's not really necessary.

Thanks to all for your help.
I put off the `sync' option from my /etc/fstab.
Douglas, my pendrive never stops flashing as long as it is inserted in the usb
location: he must be in love with the PC.  So I'm going to run the
`sync' command after the backup and wait until the prompt returns
back.  Then I will unmount the drive.
Will it this way be really _safe_?  I.e., am I sure that the copy is
finished when the `sync' command turns the prompt back?


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