Cobol - Re: IBM Mainframe Storage

Author

Re: IBM Mainframe Storage - DVD Drives?

epc8@juno.com

2005-06-02, 8:55 am

docdwarf@panix.com wrote:
> So here's the situation... case upon case of 9-track tape reels, taking up
> space and incurring storage costs.
>
> Someone suggests transferring them to DVD... is there such a thing as a
> mainframe DVD-jukebox? If so, where might such a thing be researched? A
> Google search on "mainframe DVD drive" yields zero hits while '"DVD drive"
> mainframe' yields over 8,000 pages.
>
> DD

A quick Google search on "dvd jukebox" and mainframe gives a smaller
number of hits. Apparently JVC and Pioneer make them.

But will there be enough storage capacity? There's a large JVC 600 disk
unit (double sided DVD) that stores 5.64 TB. At 50 GB per mag tape
that's about 112 tapes.

It looks like they use SCSI.

docdwarf@panix.com

2005-06-02, 3:55 pm

In article <1117677826.890937.42620@g47g2000cwa.googlegroups.com>,
<epc8@juno.com> wrote:
>
>
>docdwarf@panix.com wrote:
>
>A quick Google search on "dvd jukebox" and mainframe gives a smaller
>number of hits. Apparently JVC and Pioneer make them.

This helps cut things down, aye.

>
>But will there be enough storage capacity? There's a large JVC 600 disk
>unit (double sided DVD) that stores 5.64 TB. At 50 GB per mag tape
>that's about 112 tapes.
>
>It looks like they use SCSI.

The more I look at this the more it seems that - at least for initial
configuration - it is something that The Pros need to be called in on...
kids, don't try this at home!

Thanks much!

DD

Joel C. Ewing

2005-06-02, 3:55 pm

docdwarf@panix.com wrote:
> In article <1117677826.890937.42620@g47g2000cwa.googlegroups.com>,
> <epc8@juno.com> wrote:
>
>
>
> This helps cut things down, aye.
>
>

Max capacity of 2400' 9-track tape reel at 6250 bpi with an efficient
blocksize is closer to 120 MB, not 50 GB. That would potentially allow
5+ tape images even on an ordinary CD, or around 39+ on a single 4.7GB
DVD. It is very unlikely that 100% of the tape capacity was used in
most cases, so the actual number of tapes per DVD could be much higher.

While IBM does have an optical solution using a 3995 device and OAM, you
wouldn't be able to access the data in the same way as a tape dataset.
A solution that involves multiple optical media, 3995 or some DVD
solution, would reduce the size of the media storage, but if you
actually need to read the data you would be trading the mechanical
problems of 9-track drives for the mechanical problems of a "jukebox",
which can be significant.

One interesting thought, which I would be tempted to explore as a
possibility: a mere 400 GB of hard drive space on on workstation (not
that expensive these days) could potentially store over 30,000 9-track
tapes. If that workstation has TCP/IP connectivity to the system
needing to access the 9-track tapes, then it could run as an NFS file
server, store tape images, and make images of the tapes remotely
available to an NFS client on the system needing the data. An ordinary
DVD writer on the workstation could be used for backups and Disaster
Recovery of the images on the workstation, but you wouldn't be exposed
to media handling and the associated mechanical failures during normal
reading of the data from the hard drive. This should be cheap to
experiment with if you already have IP connectivity and an idle
workstation capable of running Linux; and the data transport to the
target system doesn't require any expensive interfaces or the invention
of any new techniques.

[color=darkred]
>
>
> The more I look at this the more it seems that - at least for initial
> configuration - it is something that The Pros need to be called in on...
> kids, don't try this at home!
>
> Thanks much!
>
> DD
>

docdwarf@panix.com

2005-06-02, 3:55 pm

In article <gcGne.5164$MI4.719@newsread2.news.pas.earthlink.net>,
Joel C. Ewing <jcREMOVEewing@CAPSacm.org> wrote:

[snip]

>One interesting thought, which I would be tempted to explore as a
>possibility: a mere 400 GB of hard drive space on on workstation (not
>that expensive these days) could potentially store over 30,000 9-track
>tapes. If that workstation has TCP/IP connectivity to the system
>needing to access the 9-track tapes, then it could run as an NFS file
>server, store tape images, and make images of the tapes remotely
>available to an NFS client on the system needing the data. An ordinary
>DVD writer on the workstation could be used for backups and Disaster
>Recovery of the images on the workstation, but you wouldn't be exposed
>to media handling and the associated mechanical failures during normal
>reading of the data from the hard drive. This should be cheap to
>experiment with if you already have IP connectivity and an idle
>workstation capable of running Linux; and the data transport to the
>target system doesn't require any expensive interfaces or the invention
>of any new techniques.

*Most* interesting... thanks much!

DD

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