It won’t effect storage IO and if you have your logs + DB on the same file system you should retain crash consistency. If they are on separate volumes you will probably need sync snapmirror which is much more network intensive but should give you the best chance of it coming back up more or less cleanly. We’ve had good results doing the former.

Is it possible for a snapmirror update command (one not mediated by SnapDrive) to temporarily halt I/O on the source disk?  More to the point, is it possible for a snapmirror update command to harm the source server if that server is an active Exchange 2003 box?

We do own SnapDrive for Exchange, but installing it is not an option at this time. 

This snapmirror solution is being suggested as an emergency solution to replicate our Exchange database for the next few days, while our operations team tries to figure out why DoubleTake has failed for four days in a row.  They understand that without SnapDrive’s VSS goodness there is a good chance of data loss on the target end, but they’d like to give this a shot on the theory that it’s better than nothing.

But it’s only better than nothing if it doesn’t interfere with the production (source) server, hence my inquiry.  If there is any chance of an I/O suspension that could take the production server offline, then obviously this is a nonstarter. 

Many thanks.

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