Incremental Backups (AREV Specific)
At 29 MAY 2003 09:34:36AM Jenna Pederson wrote:
Does anyone know whether an incremental backup of an ARev system will work?
At 29 MAY 2003 10:23AM Don Miller - C3 Inc. wrote:
Jenna ..
I don't recommend incremental or differential backups for AREV files .. there are too many places where things get modified. It's hard to glue all the pieces together in the event of disaster. It's bad enough to get backups done if there's a dedicated indexer running at some sites. Just my $.00002 ..
Don M.
At 13 JUN 2003 02:18PM Patrick Duyck wrote:
how about using a mirrored drive method?
At 13 JUN 2003 02:22PM Patrick Duyck wrote:
mirrored drive method probably wouldn't work as it couldn't detect an AREV problem and would simply mirror any errors immediately. hmmm … perhaps a custom process within AREV to save off critical data to AREV tables at a different network location. such a process could be programmed with the specifics of what to save and when.
At 13 JUN 2003 03:11PM David Craig wrote:
Don;
Could you provide any more detail? We have been using differential backups for about a year now so I am concerned that maybe it's not a good strategy. If I wanted to get it changed for our data I would need something solid to make the case.
Thanks in advance;
David Craig.
ABc-CLIO
At 13 JUN 2003 04:01PM Victor Engel wrote:
There can sometimes be a problem, but I don't think you need to worry if you manage things properly. All you have to do is to remember that the LK and OV files must be in sync. Generally, if there is a change to one, there is usually a change to the other one as well. But this is not always the case. If it's not the case, you needn't worry since restoring the file that didn't change (from the last full backup) will get you what you need.
That is a key to remember. To properly restore from an incremental backup, you must start with the last full backup taken prior to it.
A similar logic applies to REVMEDIA files vs. data files and data files vs. dictionary vs. index files. Although, with indexes, you can rebuild them if necessary.
For all practical purposes, I've found that for Arev files, there is not that much difference between an incremental vs. a full backup. This is because even for a small change, the entire file is marked as having changed. For this reason, it could simply be easier to manage a full backup.
The only problem I've ever had with incremental backups was when tapes were bad. The same problem would have occurred with a full backup.
At 23 JUN 2003 12:22PM David Craig wrote:
Thanks Victor;
It sounds like as long as we know the issues we can work with the incremental backups.
David Craig.