Yes, common in many environments.
Yes, you can use multiple streams from a DSSU to tape....works quite
well in practice.
6 is supposed to work better than 5, in that you can group DSSUs, like
regular STUs, so if one fills up, backups go to another with available
space.

When you destage to tape from disk, the data is supposed to stay on disk
untill free space is required....Netbackup attempts to keep the DSSU as
full as possible, so that data can be restored from disk rather than
tape. The data is only purged from disk when another backup tries to
write to the disk and determines the disk is full...then several of the
oldest images on disk, that have already been destaged to tape, will be
purged from disk to make room for the new backup.

Paul

-- 


> -----Original Message-----
> From: veritas-bu-bounces at mailman.eng.auburn.edu 
> [mailto:veritas-bu-bounces at mailman.eng.auburn.edu] On Behalf 
> Of Justin Piszcz
> Sent: June 20, 2006 12:06 PM
> To: veritas-bu at mailman.eng.auburn.edu
> Subject: [Veritas-bu] Fronting backups with disk then 
> bleeding off to tape.
> 
> 
> Does anyone do this with a massive amount of data?  Also, I 
> noticed with 
> 5.1MP4 its possible to use multiple streams to bleed from 
> disk->tape but I 
> was wondering how well this worked practice.
> 
> How many people bleed off to tape using 5.1MPx?
> Using 6.0?
> 
> How well does it work under 6 vs. 5? I know there is a 
> watermark feature. 
> Also, how come when I bled data off to tape under 5.1MP4, it did not 
> remove the images from disk?  Must I manually purge that data?
> 
> Thanks,
> 
> Justin.
> _______________________________________________
> Veritas-bu maillist  -  Veritas-bu at mailman.eng.auburn.edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
> 
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