ADSM-L

Re: direct attached disk (DAS) at a tape library?

2004-09-29 10:28:34
Subject: Re: direct attached disk (DAS) at a tape library?
From: Eliza Lau <lau AT VTCAT.CC.VT DOT EDU>
Date: Wed, 29 Sep 2004 10:28:30 -0400
Milton,

Sepaton is going to ship us a S2100-DS for testing with no commitment to
buy.  Can you share with us your experience?  Is it worth 3 times the
cost of setting up our own DASD.  Is it as easy to implement
as they claim and how is their support?  As far as I know, compression
will be available in Q1 2005.  Our goal is to put the VTL or DASD in a
building 1.5 miles away and put the primary stgpool on it.  The 3494
will stay in the machine room and will keep the 'offsite' tape pools.
Then we will never have to mess around with tape vaulting ever again.

Eliza Lau
Virginia Tech Computing Center

>
>  Bill,
>
> I am presently implementing the S2100-ES and S2100-DS VTLs by Sepaton
> which are also TSM certified.  While at present I am using them as
> directly fiber attached devices to my TSM server, I chose a VTL solution
> over a DASD solution because: (1) I wanted to preserve the ability to do
> a LANFree back-up in the future; (2) the VTL offers compression without
> any performance hit to my TSM server or clients.  As far as costs are
> concerned, sure you are paying something for the VTL layer, but
> compression decreases that cost, besides TANSTAAFL (There Ain't No Such
> Thing As A Free Lunch).  We were faced with the need for a major
> expansion and sticking with the tradition tape with a disk stgpool front
> end would have been very expensive.  Give me a month or two and I should
> be able to report on life with a TSM and VTL.
>
> H. Milton Johnson
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
> Of
> Bill Smoldt
> Sent: Wednesday, September 29, 2004 8:01 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: direct attached disk (DAS) at a tape library?
>
> Milton,
>
> After I wrote the last message, I noticed that FalconStor has certified
> TSM SAN clients with their product, which is used by EMC and other
> manufacturers.  I was thinking that it would be more interesting to run
> the VTL software on the TSM server rather than add another piece of
> hardware, however.
>
> So VTL might be a nice alternative to trying to implement a shared SAN
> filesystem (SANergy) just to achieve shared file pools.  I haven't
> looked at the price.  Have you?
>
> Bill Smoldt
> STORServer, Inc.
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
> Of
> Johnson, Milton
> Sent: Wednesday, September 29, 2004 6:48 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: direct attached disk (DAS) at a tape library?
>
>  A virtual tape library operates and connects just like a physical tape
> library in a SAN environment.  The VTL, TSM server and your client are
> connected to the SAN so a LANFREE back-up works using TSM's LANFREE
> technology.  Since the topology is conventional you should also be able
> to add a SAN Data Gateway and do a "server free backup".  The key is
> that a VTL is just a conventional fiber connected library with really
> fast robotics and drives. Yes, you do need to make sure that the VTL
> plays nice with TSM, so make sure your choice in VTL is TSM certified.
>
> H. Milton Johnson
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
> Of
> Mark D. Rodriguez
> Sent: Tuesday, September 28, 2004 10:43 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: direct attached disk (DAS) at a tape library?
>
> Johnson, Milton wrote:
>
> > I am not quite sure what you meant by "with TSM you can use disk only
> >for backups instead of onsite tape".  I do not see any reason why you
> >can not use FILE device types for both primary and copypool stg pools.
> >Of course if you actually want to move a copy of the data offsite, then
>
> >you would need some type of removable media such as tape.
> >
> >For me two of the attractions of a virtual tape library are being able
> >to do lanfree backups without using Sanergy, and having the VTL do
> >compression.
> >
> >
> >H. Milton Johnson
> >
> >
> >
> Hi Milton,
>
> I am not sure how you get to do Lan-Free without using Sanergy.  In
> order to do that wouldn't the VTL have to have some kind of similar code
> as Sanergy and then the question is does that play nicely with TSM.  Or
> am I missing something really obvious here?  Please explain how you will
> get Lan-Free to work in a TSM environment without the Sanergy code.
>
> Thank You.
>
> --
> Regards,
> Mark D. Rodriguez
> President MDR Consulting, Inc.
>
> ========================================================================
> =======
> MDR Consulting
> The very best in Technical Training and Consulting.
> IBM Advanced Business Partner
> SAIR Linux and GNU Authorized Center for Education IBM Certified
> Advanced Technical Expert, CATE AIX Support and Performance Tuning,
> RS6000 SP, TSM/ADSM and Linux Red Hat Certified Engineer, RHCE
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>
>