newbie Q about 5.0 backups
In Message-Id: <1994Sep27.084043@news.ntrs.com> mbm1@ntrs.com (Mark Meredith 312.630.6295) writes: > I just inherited an Informix 5.0 Online project, server running under AIX. I > haven't tried any backups yet and was wondering... > > Can one use tptape to do the archives to a disk device (say, a jfs volume) > instead of to tape? We do our other RDBMs this way: use their backup utils > to dump to a disk volume, and then use trusty ole system utility sysback to > perform the backup to tape. That makes our other RDBMs happy, our SysAdmin > happy, and our operators VERY happy as they have fewer tapes to mount. Sure! The "unix" way is to treat everything as a file: tapes, disks, pipes, re-directs, are all essentially the same thing to a unix process. You have to be *VERY SURE* you have enough disk space to hold the archive, or the process will ask you to change tapes. It does this about 50 times/second until it fills up the file system to which you have the output redirected! There is a script in the archives which does this. I added some code to accept as arguments the archive level (0, 1, 2) and the path/name of the file which defines the environmental variables needed. This shell should run from cron as informix, we do it every night. This shell needs to read the appropriate TBCONFIG file and get the TAPEDEV from there instead of from the tunables file, but that's a change I haven't made yet. This file is at mathcs.emory.edu in the /pub/informix. Use anon FTP. It should be called something like do_ol_backup.sh > > Obviously, I haven't tried this. The manual does not even allude to non-tape > devices, other than /dev/null, and so I wondered if this was kosher. What the hell! Go ahead and try it. > > As an alternative, I thought about exporting the critical databases to disk > (again, where our standard backups would get them). The manual advises that > they don't recommend this approach; any idea as to why? I was thinking that > perhaps one could first export the entire DB (schema and tables), perform an > archive to /dev/null, and then live happily ever after secure in the knowledge > that we have a good archive... err, I mean, backup. > TFM states (on page 3-47 of the OnLine Admin Guide v5.0): "Do not use the OnLine data-migration utilities to unload data as a substitute for a complete archive. blah blah." An archive is the whole enchilada: dbspaces, extents, locking information, ownerships and permissions and pointers and logs and... It is a great way to get back a database which has been trashed. In version 5, none of the other tools will do that. There are many good reasons to use the archive utility. Here's a tidbit, too. Under v 5 there is a *feature* in the tbmonitor utility which forbids an archive of >INTEGER size. You must give the create archive command from the command line to do this. > Your comments appreciated! > > -- > Mark B. Meredith | mbm1@ntrs.com > Northern Trust Co. | Voice: 312.630.6295 > Chicago, IL USA | FAX: 312.444.3951 My $0.02 worth, Good Luck! __________________________________________________________________ | Clem Akins Standard Disclaimers Apply | | Reynolds Metals Co. "Climb High, Cave Deep!" | | Muscle Shoals, Alabama USA cwakins@leia.alloys.rmc.com | |________________________________________________________________|