Re: LTO4 vs LTO3 speed

[PaulMmn <PaulMmn@xxxxxxxxxxxxx>]

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."