I do not think that it is the format per say. The problem is that the final program has to know how to issues tape i/o commands, which are different then disk i/o commands.
If you have the blocks of data you can run them thru the dd command which knows how to write to disk or tape. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Perrin Sent: Monday, November 27, 2006 9:46 PM To: Triangle Linux Users Group discussion list Subject: Re: [TriLUG] Using gzip to backup postgres to tape On Mon, 27 Nov 2006, Brian Henning wrote: > o A gzipped tar isn't tar format; it's gzip format. The tape drive doesn't > know what to do with gzip and chokes. I agree with this empirically, but it doesn't make sense to me, since tar -zf /dev/nst0 works, and man tar says: -z, --gzip, --gunzip, --ungzip filter the archive through gzip so it seems like there ought to be a way to make gzip spit out gzipped tar data that will write to the tape. But nevertheless... > ... script the > following steps: > > 1) Dump from postgre through gzip into a file. Don't worry about tar format; > dump it however postgre likes it when it's time to restore. > > pg_dump --make-restore-easier mydatabase | gzip [-9] tempdump.gz > > (where --make-restore-easier is whatever set of flags and options makes > restoration easiest, and [-9] means optionally specify maximum gzip > compression) > > 2) Tar the gzipped file onto the tape drive > > tar -cvf /dev/nst0 tempdump.gz > > 3) Delete the temporary file > > rm tempdump.gz This is a clever approach, and I'll try it tomorrow. Thanks - kludgy, but clever. Andy ---------------------------------------------------------------------- Andrew J Perrin - andrew_perrin (at) unc.edu - http://perrin.socsci.unc.edu Assistant Professor of Sociology; Book Review Editor, _Social Forces_ University of North Carolina - CB#3210, Chapel Hill, NC 27599-3210 USA New Book: http://www.press.uchicago.edu/cgi-bin/hfs.cgi/00/178592.ctl -- TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug TriLUG Organizational FAQ : http://trilug.org/faq/ TriLUG Member Services FAQ : http://members.trilug.org/services_faq/ -- TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug TriLUG Organizational FAQ : http://trilug.org/faq/ TriLUG Member Services FAQ : http://members.trilug.org/services_faq/
