lf Of bob944
> Sent: May 23, 2006 1:28 AM
> To: veritas-bu@mailman.eng.auburn.edu; 'Darren Dunham'
> Subject: Re: [Veritas-bu] compression to disk staging unit
> "[M]ap directly onto physical tape?" With my usual subtlety and
> understatement, let me say that
On Sat, May 20, 2006 at 03:50:58AM -0400, bob944 wrote:
> > link. Even on a WAN many WAN routers use compression to improve
> > throughput.
>
> I never thought of this. Cool. Do you have an example that I can
> study?
Google for "WAN Acceleration"
these appliances typically use many techniqu
> > The idea is if you are using your VTL to produce not just random
> > storage, but map directly onto physical tape. If your local
> > compression
> > is greater than the drive's, then when you go to realize the virtual
> > tape onto physical storage, Nebackup may be tracking a single tape
> >
> > B. Because of that, as I said earlier, no tape software ever made,
> > AFAIK, makes such an assumption.
> [...]
>
> Then you are obviously not as old as me :-(
Might be--cut my teeth on 200bpi, 7-track and rememeber 3-inch-wide
tape. :-)
> Way back, ICL had something called FMS (Filestore M
> > B. Because of that, as I said earlier, no tape software ever made,
> > AFAIK, makes such an assumption.
> [...]
>
> Then you are obviously not as old as me :-(
Might be--cut my teeth on 200bpi, 7-track and rememeber 3-inch-wide
tape. :-)
> Way back, ICL had something called FMS (Filestore M
On Tue, 23 May 2006, bob944 wrote:
> > > > There are now VTLs that compress the data going to disk;
> > > > they always have
> > > > a bit of a gamble as to how well they can mimic the way
> > > > the real tape
> > > > compresses data; I'm told they just use very conservative
> > > > estimates, t
> > > There are now VTLs that compress the data going to disk;
> > > they always have
> > > a bit of a gamble as to how well they can mimic the way
> > > the real tape
> > > compresses data; I'm told they just use very conservative
> > > estimates, to make sure the disk image will fit on the t
> > There are now VTLs that compress the data going to disk; they always
> have
> > a bit of a gamble as to how well they can mimic the way the real tape
> > compresses data; I'm told they just use very conservative
> > estimates, to make sure the disk image will fit on the tape.
>
> I think if you turn on software compression this only applies
> to the data "in-flight", i.e. it is compressed by the client but
> decompressed by the server, regardless of the type of storage unit.
^^
What makes you say this?
> link. Even on a WAN many WAN routers
as-bu@mailman.eng.auburn.edu
cc
Subject
[Veritas-bu] compression to disk staging unit
Is it wrong to use software compression in a policy that uses a disk
staging unit for the storage unit?
Will this result in slower migration or negative compression during the
migration phase to
[mailto:[EMAIL PROTECTED] On Behalf Of Bob
StumpSent: Friday, May 19, 2006 8:42 AMTo:
veritas-bu@mailman.eng.auburn.eduSubject: [Veritas-bu] compression to
disk staging unit
Is it wrong to use software compression in a policy that uses a disk
staging unit for the storage unit?
Will this result in slo
to disk staging unit
Is it wrong to use software compression in a policy that uses a disk
staging unit for the storage unit?
Will this result in slower migration or negative compression during the
migration phase to a tape drive that uses hardware
compression?
This email is for the
Is it wrong to use software compression in a policy that uses a disk staging unit for the storage unit?
Will this result in slower migration or negative compression during the migration phase to a tape drive that uses hardware compression?
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