Re: How to backup a postgreSQL of 80 GByte ?

On Mon, 23 Dec 2002, Michelle Konzack wrote:

> Oops... and Hello,
>
> Am 11:39 2002-12-23 +0100 hat SZUCS Gábor geschrieben:
> >
>
> >Call me suspicious, but 830 THOUSAND millions of tables in 80Gbyte is a
>
> 8-O ...a little BIG error... they are ONLY 830.000 tables ! :-P
>
> >As for the hardware, I agree with Scott regarding tapes. The typical thing
> >to backup/archive. As for its speed-- well, let's hope you won't have to
> >restore from it ;)
>
> Curently I am using the Software RAID-1 with two Harddrives...
> Maybe I will switch to RAID-5 with 3 Drives.
>
> >As for compression, bzip2 is really much better on text files. Also don't
> >forget the "-9" flag (though I think this should be the default).
>
> But HOW do you backup 80 GBytes ???
>
> OK, I have three drives and the first drive is a normal 120 GByte HD,
> on which I have the OS and a around 120 Gbyte TEMP Partition !!!
>
> If I try to 'gzip' or 'bzip2' the 80 GBytes, how many days need it ???

If you have a VXA2 drive (80 gig native, 160 gig compressed) then you
don't do anything of the sort. Those drives achieve a respectable amount
of compression on database backups, and pre-compressing your data means
the compression in the drive hasn't got much left to work with.

So, just dump it straight to tape.

mt density 0x00
mt rewind
pg_dump -options here database_name >/dev/nst0

> OK, I use the HP Surstore 12000e with 16 GByte Tapes...

That's way too small. You can get a VXA2 drive for <$1000 and while not
quite as fast as the monster mammoth from exabyte, it is 1/3 the cost.

Plus, with it's packet writing scheme, you almost can't get an error on
restore. Great tape drives, I'm glad exabyte bought them out so they
didn't disappear due to being underfunded/marketed.