Re: Ontape restore hangs

Posted in 2008

Topics: Backup & Restore, Performance & Tuning, Platform-Specific Issues, Jobs, Consulting & Announcements

Keith Simmons — Wed, 24 Sep 2008 14:27:32 +0100 — source: Usenet: comp.databases.informix

2008/9/24 Obnoxio The Clown <obnoxio@serendipita.com>: > Captain Pedantic wrote: >> "Doug Lawry" <lawry@nildram.co.uk> wrote in message >> news:N5mdnfW0JLeCrkfVnZ2dnUVZ8v6dnZ2d@pipex.net... >> >>> This turned out just to be slow performance rather than a hung ontape, and >>> increasing TAPESIZE makes all the difference even when using backup images >>> on disk. It may be peculiar to this disk array (Dell PowerVault MD3000). >>> >>> Astonishingly, with TAPESIZE 1024 (the largest suggested value I had seen) >>> instead of 32 (the default), the restore completed in 55 minutes (about >>> the same as "dd") instead of several hours, so I'll be making this change >>> everywhere else! >>> >> >> You should get a top Informix consultant called Paul Watson in for a day. >> He's always banging on about the performance benefits of large TAPEBLK ...! >> > > Clowns do too ... ;o) > > -- > Cheers, > Obnoxio the Clown > > http://obotheclown.blogspot.com > > > > > > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list > Beware having too large a BLK however. I've crashed an AIX box with a large BLK on a fibre attached drive. Use dd with varying block sizes to determine the largest that works before implementing it. Keith

↪ replying to Keith Simmons

Doug Lawry — Thu, 25 Sep 2008 07:45:09 +0100 — source: Usenet: comp.databases.informix

"Keith Simmons" <smiley73@googlemail.com> wrote in message news:mailman.1801.1222263206.20610.informix-list@iiug.org... > 2008/9/24 Obnoxio The Clown <obnoxio@serendipita.com>: >> Captain Pedantic wrote: >>> "Doug Lawry" <lawry@nildram.co.uk> wrote in message >>> news:N5mdnfW0JLeCrkfVnZ2dnUVZ8v6dnZ2d@pipex.net... >>> >>>> This turned out just to be slow performance rather than a hung ontape, >>>> and >>>> increasing TAPESIZE makes all the difference even when using backup >>>> images >>>> on disk. It may be peculiar to this disk array (Dell PowerVault >>>> MD3000). >>>> >>>> Astonishingly, with TAPESIZE 1024 (the largest suggested value I had >>>> seen) >>>> instead of 32 (the default), the restore completed in 55 minutes (about >>>> the same as "dd") instead of several hours, so I'll be making this >>>> change >>>> everywhere else! >>>> >>> >>> You should get a top Informix consultant called Paul Watson in for a >>> day. >>> He's always banging on about the performance benefits of large TAPEBLK >>> ...! >>> >> >> Clowns do too ... ;o) >> >> -- >> Cheers, >> Obnoxio the Clown >> >> http://obotheclown.blogspot.com >> >> _______________________________________________ >> Informix-list mailing list >> Informix-list@iiug.org >> http://www.iiug.org/mailman/listinfo/informix-list >> > Beware having too large a BLK however. I've crashed an AIX box with a > large BLK on a fibre attached drive. Use dd with varying block sizes > to determine the largest that works before implementing it. > > Keith Thanks :-)

Glossary

ontape