Re: New data reported too big

[Andy Lutomirski <luto@amacapital.net>]

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".

--Andy

> --
> Colin Percival
> Security Officer Emeritus, FreeBSD | The power to serve
> Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid
>



-- 
Andy Lutomirski
AMA Capital Management, LLC