Well as much as a pain as they are , enabling collections is a good start, for the fact that its quicker to backup 1 x 10mb file as opposed to 100 x 100k files
and with the new ev8 OSIS you will have far more small DVS files than you would have had in EV2007.
Read-only is obviously the more efficient way to go about things, as it keeps the systems up and running without interruption to the users except for archiving.
Though restarting the services every so often to clear out memory etc is still a good idea.
You may want to also look at partition roll over and close a partition every quarter or half a year or even a year, that way when the partition is closed, nothing new will be written to it, so then you can do full/differential backups.
If you use After Backup as your Safety Copy mode on your partitions then you may want to look in to which types of backup remove the archive bit, so that you're not sitting with pending items for a week waiting for your backup to run and so items can be turned to shortcuts
the most efficient backups ive seen though have been snapshots and then backups made from the snapshots
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