Re: I can't lose a single transaction, how 2 backup?

Gilbert Gosseyn wrote: > > I set up a very important database and I wnat to protect myself against HD > failure. Every day I make a level 0 backup and I start to perform backup of > full logical logs. But what happen if my HD crash before the logical log fills? > All the transaction inside the last-not-filled logical log will be lost? > Thank you in advance > > Leandro Leandro... You should be mirroring your disks at minimum. Then both disks of a pair (primary and it's mirror, - *not* just any pair...) would have to fail within a small time window to produce data loss. This is extremely unlikely. Better yet, your disk array should have a "hot spare" to replace any failed drive immediately, then it takes 3 specific disk failures to produce data loss (primary + secondary + hot spare). Your disk array should also have enough battery power on board to finish commiting any writes and shut down gracefully on a power outage -5 minutes minimum, or have ample UPS for the system to run indefinitely. If that's not good enough, triple mirror (I know of people who do this with >500GB databases...). If you are concerned about nuclear attack, you may need to replicate across a wide area to a hot site far, far away. OK - I'm getting a little silly but you get my point - you'll still have decisions to make about how serious you are about "not losing a single txn" and how much money you are willing to back up that assertion with. Every additional layer of safety costs more and more. From the log backup standpoint, you should be doing continuous backup of logs, to get them off to tape as soon as possible. Keep your logfiles small so not much stuff is stuck in an un-backed up log, should catastrophe strike (oops, I shoudn't have dropped that table...). You'll find out how important the data *really* is when you ask for the money to go do these things. That will be the most interesting part.... Let us know how it goes.... Greg