Re: suggestion: do not keep files in tar archives.

Boris Goldowsky <[email protected]> writes:

| It strikes me that if what you want is an uncompressed mirror of your
| disk, there are other programs around which should do that for you.  If
| you want to achieve the effect of 
|     tar <options for sender> | ssh server '(cd BackUpDir; tar xpf - )'
| it is generally more efficient to use rsync rather than tar, and I know
| that there are several scripts people have written to run rsync nightly
| to update a mirror.  You can choose what you want to do with files that
| have been deleted on the main disk -- make in-place backups, have
| snapshot directories of previous days, etc.  Try searching for 'rsync
| backup' on freshmeat.net and you'll get a list of several programs of
| this sort,I believe.
| 
| If the goal is rather to replace tar archives with afio archives, then
| it may be appropriate to patch that into hdup -- but I hope tar will
| remain an option, since afio is not standard on many platforms (and the
| version that can handle large files appears to still be listed as beta).
I want to keep the possibility of having daily incremental back ups, something I don't
get with just mirroring. Still I also want to have fast access (secs rather
than several hours) to the files of the backup.

Cheers
Jesper.

| 
| Bng
| 
| 
| On Tue, 2003-12-16 at 02:23, Jesper K. Pedersen wrote:
| > blackie-1tkZHNPFh85/[email protected] (Jesper K. Pedersen) writes:
| > 
| > | Hi.
| > | 
| > | Yesterday I needed to restore a file from my hdup for the first time, and
| > | that thought me something new, namely that things can only go too slow when
| > | restoring.
| > | 
| > | Unfortunately it went way to slow for my - at the moment - temper.
| > | That made me start doing a bit of math.
| > | 
| > | I back up all of my hard disk, which includes all my digital photos etc, so
| > | the total backup is approx 32Gb for the base backup.
| > | 
| > | I do the backup on a IDE disk connected though a USB wrapper device, which
| > | is not utterly fast, but I don't really care, the priority is that I can
| > | easily detach it from the rest of the system. I measured that the device
| > | could copy in the order of magnitude 1Mb of data per sec.
| > | 
| > | Thus to simply read though the base file, I need to wait for 32.000 sec = 9
| > | hours. And I do need that, as I understand tar.
| > | 
| > | 9 hours is a looooong time when you accidently deleted a very important
| > | file from say your web server.
| > | 
| > | My suggestion is to unpack the files on the disk when copying over,
| > | something along those lines:
| > | 
| > | tar <options for sender> | ssh server '(cd BackUpDir; tar xpf - )'
| > | 
| > | This would store all the files on the disk, and I could thus access them
| > | very fast (within secs), as I would have random access to them.
| > | 
| > | Hope you like the idea and soon find time for implementing it.
| > | 
| > | Cheers
| > | Jesper.
| > I just discussed the issue with some of my coworkers, and they suggested
| > that afio is capable of doing random access in the files. Thus replacing
| > tar with afio in hdup might be even simpler than the above suggestion.
| > 
| > Cheers
| > Jesper
| 

-- 
Jesper K. Pedersen          |  Klarälvdalens Datakonsult
Senior Software Engineer    |  www.klaralvdalens-datakonsult.se
Peder Skrams Gade 27 3. tv. |
6700 Esbjerg                |  Platform-independent
Denmark                     |  software solutions