> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Brian Leach > Sent: Wednesday, May 14, 2008 1:20 AM > To: u2-users@listserver.u2ug.org > Subject: RE: [U2] Backup Question > > John et al > > > I've also used the unix/linux OS-level cp command > > to make a duplicate copy of our entire production database for > > development use evey night for the past 12 years, and have > yet to run > > into a single issue with file integrity. > > That's only possibly valid if you don't use dynamic files or > secondary indices. Both of those will cause huge problems if > you try to backup and copy at the OS level. > > - dynamic files may break as the load counters are held in > shared memory. > - secondary indices hold absolute pathnames in the file header. > > A classic error is to take a copy of a file to play around > with not noticing that it has a secondary index attached. > Then any changes to that file will affect the LIVE index. > > Brian
We don't use any indices, so I've never run into that issue, although I've heard cautionary tales about it many times. Seems like someone posted in the recent past that the latest versions of UV stopped using absolute pathnames for the indices, though, and now use relative path names. I assume that means you can now do an OS level copy without having to worry about your copied index pointing to the wrong file. As far as the dynamic file issue, we have quite a few dynamic files, and I've never had an issue with copying them while the database was idle. Could be we've just been lucky, but the development area is actively used for development and training on a daily basis, so that seems statistically improbable. Is it possible the load counters are periodically flushed to disk? -John ------- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
