Re: LTO4 vs LTO3 speed

Charles--

We switched to the SAVFs about 3 months ago. Using SAVFs was not a goal as such-- we were trying to save security data, user profiles, &c. at a time when users were still using the system hot 'n' heavy. Saving such objects while they're in use takes a lot longer than at 4 AM! Why SAVFs? Because our daily backups had a nasty habit of running long and tying up the tape drives into the 4 AM time slot!

By moving the system stuff saves to 4 AM the daily backups to tape run 'faster' since the data's already collected and ready to dump to tape.

--Paul E Musselman
PaulMmn@xxxxxxxxxxxxxxxxxxxx




At 8:58 AM -0400 6/16/13, Charles Wilt wrote:

Paul,

How long ago did you move to the saving SAVFs?

Reason I ask, I worked on a system that originally did that. But after a
couple of upgrades, it was faster to save directly to tape.

Its a smaller box, so it only has 8 disks. So the limiting factor isn't
really the tape, it's the disks. Reading and writing to the same set was
slower than streaming to the tape directly.

Charles


On Fri, Jun 14, 2013 at 5:11 PM, Musselman, Paul <
pmusselman@xxxxxxxxxxxxxxxx> wrote:

Have you looked at what kinds of things you're saving? Lots of little
things take more time to write to tape than a few big things!

We needed to structure our backups more efficiently, so we changed saves
of some of the system stuff-- outqs, journals, configuration, history logs,

> security data, etc. to use SAVFs in a "SAVF Library."