2) Sepaton does hardware compression so as far as I can tell it performs like
compression on physical drives, I imagine other vendors may also use hardware
compression. Besides what's important to me is that my TSM clients and TSM
server are not taking a performance hit from doing compression
1.) yes
2.) pls give me vendor / machine type of VTLs which does compression
without performance impacts.
physical tape drives gets performance improvements of compression, but VTL
gets normally much slower performance if compression is enabled
3.) you need compare the same technology. You
2.) pls give me vendor / machine type of VTLs which does compression
without performance impacts.
Several of them are now using hardware compression. They use the same
chip as the tape drives do, therefore, they get what you're asking for.
(I don't want to give vendor names cause the names will
Why a VTL vs FILE devclass volumes on local drives?
1) With a VTL you can do LAN free backups.
2) Data Compression:
2A) TSM Client does compression: Big performance hit on the client,
slower backups/restores
2B) TSM server does compression (FILE devclass volumes on compressed
file systems): Big
I think you hit every nail right on the head, Milton. I would emphasize
#5, as people tend to minimize how big of a deal it is to provision and
administer large amounts of disk. A GOOD VTL (not all are good) will
make that provisioning issue go away.
As to de-dupe, it's considered by many to be
On Wed, 13 Jun 2007 08:43:43 -0400, Johnson, Milton [EMAIL PROTECTED]
said:
The VTL is a Sepaton S2100-ES and yes it is disk only.
I don't see the benefit that a tape backed system would bring, how
does that really differ from a physical tape ATL with TSM providing
a DISKPOOL front end?
The VTL is a Sepaton S2100-ES and yes it is disk only.
I don't see the benefit that a tape backed system would bring, how
does that really differ from a physical tape ATL with TSM providing a
DISKPOOL front end?
Fewer tape-head-hours: I understand your confusion, there was no way
to reduce
As I see it, there are two areas where you get performance hits when
restoring from non-collocated volumes:
1) Tapes Mounts: In my experience my VTL makes this problem
insignificant.
2) Spinning Sequential Media: Yes, VTL volumes are sequential and if
you define your tapes as 50GB native and
I'm not looking at the spinning through the volume to find the file, I'm
focused on the fact that a volume can only be accessed by one client at a
time. You have to read the data to be restored, which takes time. If you
have one client reading the volume, any other access to that volume has to
Yes a virtual tape volume can be accessed only by one client at a time
and if two processes/clients try to access the same volume at the same
time one process/client must wait. Again smaller volume sizes decreases
the chance that a contention would happen and also decrease the
contention
On Tue, 12 Jun 2007 12:16:27 -0400, Johnson, Milton [EMAIL PROTECTED]
said:
Why a VTL? With us we found that when we out grew our physical
library we would have to have to buy over 30 physical drives in
order to be able to do backups, restores, cut off-site tapes and
reclaim on/off site
A couple of comments about what Wanda said about collocation and VTL's:
At some point, you do have a finite number of mount points defined for your
VTL. Even if virtual tape mounts are near instant, there is still some
overhead. A large number of clients mounting virtual tape after virtual
tape
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