>>So we do have to kick people out for a period, but it is a shorter period of time than it takes to do the tape backup because we are copying hard drive to hard drive. This may not be a viable solution in your situation though.
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>There are plenty of storage solutions available that can move data to tape at least as quickly as data can be written to disk; DLT and AIT are two tape technologies that have data rates that can exceed the sustainable data rate off a hard drive. There are others as well.

We use an Onstream SCSI SC30 internal tape drive. It uses what they call ADR (Advanced Digital Recording) technology. It can go up to 70Mb per second. It is a lot faster than out older tape drives. But slower than our hard drive copy.

>My approach at Weatherhill as well as my clients' sites has been to snapshot the entire schema nightly during off-hours, and to snapshot transaction journals at periodic intervals during the working day, which reduces system unavailablity during our operational hours significantly and protects our committed activity with greater frequency. We also rigorously plan and implement checkpoint/restart processing on irreversable/uninterruptable processes.>

We also take snapshots of the data before some irreversable/uninterruptable processes. Of course, another solution is to make the irreversable process reversable. This of course can be done; but at what cost? We have come to the conclusion for some of our processes it is best just to take a copy of the data before we execute the process so we can restore if there is some deadly error/problem.

Take care,
Joe