Re: Rsync options –update and –append-verify

[Kevin Korb]

I thought I did elaborate.  If it is a problem for you then maybe you
shouldn't be using --update.  Or you should let rsync delete incomplete
files upon abort as it does by default.

On 9/11/21 9:29 PM, hancooper wrote:
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On Saturday, September 11, 2021 11:20 PM, Kevin Korb via rsync <rsync at lists.samba.org> wrote:
> 
>> --archive is all you really need. I actually wish --archive was the
>> default because it is all most people need and with the exception of
>> writing to a FAT filesystem it is almost always needed.
>>
>> --append is for very special cases and should only be used if you really
>> know you need it and why. --append-verify only exists because people
>> seem to think they need --append and get annoyed that it corrupts their
>> files.
>>
>> --update is sometimes helpful however it interacts badly with --partial
>> and --inplace.
> 
> That's right.  Can you elaborate how --update interacts badly with --partial
> and --inplace?
> 
>> Since rsync doesn't set the timestamp of a file until it
>> is finished then any file left incomplete by an aborted rsync will have
>> the timestamp of the abort not the source file. Therefore it will be
>> newer than the source file and unless the source is updated rsync
>> --update will never complete the file.
> 
> Is there a solution to this problem and should we consider it a bug?
> I am encountering this, and it's a real problem for me if files are
> not completed.
> 
>> On 9/11/21 6:50 PM, hancooper via rsync wrote:
>>
>>> I am struggling to understand exactly what the rsync options --update and --append-verify do.
>>> Doing info rsync gives
>>> -u, --update
>>> This forces rsync to skip any files which exist on the destina‐
>>> tion and have a modified time that is newer than the source
>>> file. (If an existing destination file has a modification time
>>> equal to the source file’s, it will be updated if the sizes are
>>> different.)
>>> --append-verify
>>> This works just like the --append option, but the existing data
>>> on the receiving side is included in the full-file checksum
>>> verification step, which will cause a file to be resent if the
>>> final verification step fails (rsync uses a normal, non-append‐
>>> ing --inplace transfer for the resend).
>>> I am using rsync to transfer directories recursively. There are times where I have to stop the rsync transfer, and resume the transfer a few hours or days later, without affecting the already transferred files at destination.
>>> I also got some files that return errors by rsync, such as
>>> rsync: read errors mapping "/media/hc1/a1-chaos/amvib/IACL-2017-07-19T00:00:00-2017-07-19T23:59:59.mseed": Input/output error (5)
>>> I would like to retry the transfer of these files, at a later time too, without affecting the files that had been transferred successfully.
>>

-- 
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	Kevin Korb			Phone:    (407) 252-6853
	Systems Administrator		Internet:
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	Orlando, Florida		kmk at sanitarium.net (personal)
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