Re: New data reported too big

[Philipp Riegger <lists@anderedomain.de>]

On 09.10.2013 01:26, Andy Lutomirski wrote:
> On Tue, Oct 8, 2013 at 4:19 PM, Colin Percival <cperciva@tarsnap.com> wrote:
>> On 10/07/13 10:37, Andy Lutomirski wrote:
>>> On Sun, Oct 6, 2013 at 3:46 PM, Colin Percival <cperciva@tarsnap.com> wrote:
>>>> On 10/06/13 14:26, Andy Lutomirski wrote:
>>>>> On Sun, Sep 29, 2013 at 10:27 AM, Colin Percival <cperciva@tarsnap.com> wrote:
>>>>>> Tarsnap stores a 512-byte tar header for each file, and this header
>>>>>> includes the file modification time. 22,000 files x 512 bytes/file = 11.2
>>>>>> MB, so this looks like the reason for the new data you're seeing.
>>>>>
>>>>> Aha!  Is there an easy way to turn that off?  I archive a fair amount
>>>>> of autogenerated data, and the timestamps are completely worthless as
>>>>> far as I'm concerned.
>>>>
>>>> No way to turn it off.  The best I can suggest is to compare your old and
>>>> new autogenerated data and only install the new data if it's different.
>>>
>>> Yuck.  Can I request this as a feature for the next release
>>> (--no-cmtime or something like that)?
>>
>> I've put this onto my "requested features" list, but at the moment I can't see
>> any good way to do this -- the (tar) format Tarsnap uses internally has a field
>> for file modification time and if I just zero that field you'd get files being
>> extracted with an mtime of January 1, 1970...
>>
> 
> That's would actually be fine with me.  You could also use some other
> sentinel value that gets extracted as "now".

Shouldn't it be possible to reset ctime and mtime of files before adding
them to the archive (in a script, outside of tarsnap)?

Philipp