times difference causes write

Don Mahurin dmahurin at berkeley.innomedia.com
Wed Nov 14 08:36:34 EST 2001

My first problem is that I am writing to compact flash, so I want the minimal
number of writes.
My second problem is that the flash is of limited size, so I need some sort
of patch rsync that does not keep the old file before writing the new one.
My patch now just unlinks the file ahead, and implies -W.

So my wish was that a time discrepancy would lead to a checksum, where the
files would match.
This is not the case, however, as you say.

So for now, I must use -c.  It's slow, but I know that I get the minimum
number of writes.


tim.conway at philips.com wrote:

> In the example you give, yes, a time difference causes a write.  You are
> using the -W (--whole-file) option, which directs rsync to simply send the
> file, in its entirety, if there is a discrepency in mtime (ctime too?), or
> extent.  It is used for situations where file access is slow enough that
> trying to do an incremental update would take more time/resources than
> simply sending the file... primary example being nfs-mounted filesystems.
> If you have fast dasd/slow network, you should probably just drop the -W.

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