Database Backup Tools: Real-Time

G

google_tx

New Member
Hi all.

I am hoping to get some feedback on a backup method we are investigating. We would like to use a product called Livevault to backup our Progress 9.1C databases in near-real-time to a vault. The product monitors all of the database files and as soon as it sees that nothing has been written to any of the data files for a period of time it takes a snapshot and replicates it to the vault.

Does anyone see any issues with this method? We have done some testing it with and have had no issues. However, one colleague brought up the point that it is possible there is data corruption that will not show up for months or even years.

Any thoughts?

Thanks!
Roger.
 
9.1C is, of course, ancient, obsolete and unsupported. You should, of course, upgrade.

Progress has certified 10.1C to work with similar products. In theory the principles are the same and so long as the snapshot really is a snapshot of all of the database simultaneously taken and reflecting all pending IO then yes, it should work. You will have a crashed database but it should not be corrupt.

You could also do a "probkup online" and/or use after-imaging to achieve the same result without any risk.

(You should be using after-imaging in any event. All databases should have after-imaging enabled. It is the simplest and most basic litmus test of DBA competence.)
 
I hear alarm bells ringing.

I think others with more detailed knowledge of the internals of Progress will get back to you on this one. My strong feeling is that you're asking for trouble backing-up the DB files unless the Brokers are all shut-down. The risk is that some updates to the DB may not be written to disc yet.

If your database is "live" the only method of backing up that you can be sure will work is by using PROBKUP. You can send the backup to tape or disc (if you have the space).

Just out of curiosity - have you thought about upgrading to 9.1E? V 9.1C (and D) are no longer supported at all. V 9.1E is supported ("just").

Ron.
 
I understand the alarm bells, but my feeling is since it is taking a snapshot of all the database files simultaneously at a bit-level the worst case scenario will be a crashed database, but the data should be intact and not corrupted.

Unfortunately the version of the ERP package that we are running does not support a higher version of Progress. If the ERP package were upgraded it would support 10.1C but right now that is not an option.

Thanks!
 
You do realize, of course, that the restriction on upgrading the Progress is a totally artificial one being imposed by an AP that cares more about minimizing work than for the welfare of their customers.
 
If you can compile the code you can upgrade to any release you want to and your ERP vendor will never know.

There are no technical reasons to restrain customers from doing so.

(Even if you cannot compile code r-code is upward compatible within a major version so you can, for instance, go all the way to 9.1E04 without any problems.)
 
Back to the topic of backing up via snapshots...

In theory this will work. But you must make sure that it really and truly is a proper snapshot. In practice these utilities are not all created equal and some of them have been known to fail. Such failures are usually only detected at the worst possible moment. Think of a snapshot backup as an extra layer of protection or a convenience feature but don't get lulled into thinking that it should be your sole backup.

There is no substitute for a proper probkup backup and correctly implemented after-imaging. After-imaging is not complicated to setup or manage and is a very low impact method for obtaining an extremely high degree of recoverability. If you are not using it you should stop what you are doing and get it implemented now. It has saved the bacon of more DBAs than any other action you can take.
 
I'm admittedly a novice...but I really don't see any benefit of even trying this (let alone paying for something to do it) when it's so easy to use After Imaging and just archive off the files.

Is this just one of those cases where someone asks "Is it possible for me to jam this stick in my eye?" and the technical answer is "Yes"?
 
If you use a snapshot as an additional backup (perhaps more frequently taken) or as a handy way to quickly make a test system I think that it's ok.

Otherwise I agree -- I think you're just setting yourself up for a whole lot of unhappiness.
 
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