The DD has a limit on the number of tape drives that can be configured and
used.
The quote below is from the DD Admin Guide (v4.9):
" Drives?From 1 to 256 tape drives are supported, depending on the
Data Domain model. The DD4xx, DD510 and DD530 systems can
have a maximum of 64 drives. All other models can have a maximum
of 128 drives, except the DD880, which can have up to 256 drives.
Note: Although one can configure up to 256 tape devices on a DD880
there is a maximum stream limit of 180 streams. Therefore, the maximum
number of concurrent backups is 180. Additional drives beyond 180 can
be configured for provisioning as per backup policies. "
Also, while I'm not finding the info, there is a similar limit on NFS
data streams. And, this limit includes all data streams, including
remote replication streams.
Rick
From: Daniel Sparrman <daniel.sparrman AT EXIST DOT SE>
To: ADSM-L AT VM.MARIST DOT EDU
Date: 09/27/2011 12:11 PM
Subject: Ang: Re: [ADSM-L] vtl versus file systems for pirmary pool
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
Not really sure where the general idea that a VTL will limit the number of
available mount points.
I'm not familiar with Data Domain, but generally speaking, the number of
virtual tape drives configured within a VTL is usually thousands. Not sure
why you'd want that many though, I always prefer having a small diskpool
infront of whatever sequential pool I have, and let the bigger files pass
the diskpoool and go straightly to the seq. pool.
As far as for LAN-free, the only available option I know of is SANergy.
And going down that road (concerning both price & complexity) will
probably make the VTL look cheap.
Not sure what kind of licensing you're talking about concerning VTL, but I
assume it's a Data Domain license and not a TSM license?
Best Regards
Daniel Sparrman
Daniel Sparrman
Exist i Stockholm AB
Växel: 08-754 98 00
Fax: 08-754 97 30
daniel.sparrman AT exist DOT se
http://www.existgruppen.se
Posthusgatan 1 761 30 NORRTÄLJE
-----"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> skrev: -----
Till: ADSM-L AT VM.MARIST DOT EDU
Från: Rick Adamson <RickAdamson AT WINN-DIXIE DOT COM>
Sänt av: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
Datum: 09/27/2011 16:52
Ärende: Re: [ADSM-L] vtl versus file systems for pirmary pool
A couple of things that I did not see mentioned here which I experienced
was.... for Data Domain the VTL is an additional license and it does
limit the available mount points (or emulated drives), where a TSM file
based pool does not. Like Wanda stated earlier depends what you can
afford !
I myself have grown fond of using the file based approach, easy to
manage, easy to configure, and never worry about an available tape drive
(virtual or otherwise). The lan-free issue is something to consider but
from what I have heard lately is that it can still be accomplished using
the file based storage. If anyone has any info on it I would appreciate
it.
~Rick
Jax, Fl.
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Tim Brown
Sent: Monday, September 26, 2011 4:05 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] vtl versus file systems for pirmary pool
What advantage does VTL emulation on a disk primary storage pool have
as compared to disk storage pool that is non vtl ?
It appears to me that a non vtl system would not require the daily
reclamation process
and also allow for more client backups to occur simultaneously.
Thanks,
Tim Brown
Systems Specialist - Project Leader
Central Hudson Gas & Electric
284 South Ave
Poughkeepsie, NY 12601
Email: tbrown AT cenhud DOT com <<mailto:tbrown AT cenhud DOT com>>
Phone: 845-486-5643
Fax: 845-486-5921
Cell: 845-235-4255
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