Disabling "quick check"

Kevin Korb kmk at sanitarium.net
Wed Oct 28 12:41:30 UTC 2015

Hash: SHA1

- --checksum generally takes a lot longer than --size-only.  A delta
transfer generally goes quicker than a checksum.  However, if you want
to make a list of what is corrupt a checksumming utility that is less
stupid than rsync can be useful.  I say that because rsync's
- --checksum is entirely unintelligent.  It will checksum every single
file on both ends including files that only exist on one end and files
that shouldn't match (the size is wrong).  At the end of --checksum
you will still have to do the delta xfers that you would do without it.

OTOH, you are using --dry-run.  If you are trying to generate a report
about what files are corrupted then only --checksum  an do that.  It
will just do it in the dumbest/slowest way possible.

On 10/28/2015 02:08 AM, Clint Olsen wrote:
> What about -c? It seems I'm getting a lot of spurious file
> transfer candidates when using:
> -avvznIi --no-o --no-g --no-p
> It's showing transfers (receive) for many files I know haven't
> been tampered with.
> Thanks,
> -Clint
> On Tue, Oct 27, 2015 at 7:53 PM, Kevin Korb <kmk at sanitarium.net 
> <mailto:kmk at sanitarium.net>> wrote:
> That is correct.  Rsync will re-copy (delta xfer unless
> --wholefile) all the files.  You can always --dry-run if you aren't
> sure.
> On 10/27/2015 10:07 PM, Clint Olsen wrote:
>> Hi:
>> I've been using rsync to create backups for a few years. A few 
>> months ago I started experiencing sector errors. I ended up 
>> replacing the drive and copying the drive data. It turns out
>> that due to the default behavior of rsync "quick check", some of
>> the files were modified without altering the modification time or
>> size, so these files are still clean in the backup. I would like
>> to recover these files, but I need to defeat the quick check in
>> order to do this. It looks like using:
>> -I, --ignore-times          don't skip files that match size and 
>> time
>> will work. I just want to confirm that this covers it. The 
>> long-form of the switch doesn't mention size, so I was concerned 
>> this was the right way to accomplish this. If there are any
>> other switches that would be useful in the context of potentially
>> corrupt files, please feel free to chime in...
>> Thanks,
>> -Clint
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