Re: Tape subsystem question

[Al Mac <macwheel99@xxxxxxxxxxx>]

TGIF

I have run into a problem with how long stuff can be safely stored on a tape.
When we backed up on diskettes, we could go 10 years and reuse what was on 
that diskette, and it was fine.  Because occasionally data lost, I found 
that if I had 2 sets of diskettes used for saves, the data was good for 10 
years.  Tapes do not seem to hold the data reliably as long as diskettes. 
They also seem more vulnerable to stuff going wrong, tape getting tangled.

There is also the issue of evolving technology.  Every few years we replace 
the computer.  It comes with a new and improved tape drive which cannot 
read the tapes we been using for the last X years.  So tapes can be used 
for backups, not for storage off-line, between computers.  CD Rom seems to 
be readable across upgraded boxes, but individual CD not hold as much stuff 
as a tape.

There are various backup systems available for AS/400 that go beyond the 
standard stuff in OS/400 ... check out BMRS in the IBM Information 
Center.  I do not have it where I work, but I understand it is very 
sophisticated, including managing a tape library for you where the tapes 
are identified as to what got backed up on what days, from what computers, 
if you using a mass backup on weekends, and only what got changed since 
last backup on weeknites, and you can have a system for when is Ok to use 
some tape again.  So it remembers volume id used ... you need into 
something that was backed up 4 weeks ago ... it tells you which volume-id 
to get.

I do not know if it also helps you manage off site rotation, and which 
tapes are encrypted.

Do you remember going back to the S/36 when backups were made on Diskette 
Magazines?  The computer processed one diskette at a time, then after each 
one was put back in the magazine, the magazine moved sideways a notch on a 
track, then the next diskette in the magazine was selected.  By this means 
you could stick in up to 20 diskettes at a time, the backup would process 
all 20, then you replace them with another 20.

Well similar architecture exists for backing up on CD Rom.  It is called a 
Juke Box.  It comes in different model sizes with respect to how many CD 
Rom the thing can handle.  The architecture is a bit different, where the 
Magazine physically moved, the Juke Box does not, in actual fact some arms 
reach out and pull out the next CD Rom to be processed, in the same way 
that records might be pulled out to be played on the Juke Box that this is 
named after.

An AS/400/iSeries typically has a tape drive built in for the purpose of 
backing up everything that is on THAT box.  However, you can deliberately 
get a backup system with the capacity for much more than THAT box, so that 
it can backup stuff for OTHER boxes.

For example, designate like a "partition" or object on the AS/400 that the 
AS/400 thinks of as being stuff that is not 400 compliant, a mirror if you 
will of what is on some other kind of system, that is to be included in the 
AS/400 backups, while to PCs connected to this it is THEIR "M" drive for 
"Mainframe" or whatever (the way PC users label the AS/400) ... so the 
individual PCs back themselves up, not to tape drive on individual PC, but 
to the "M" drive that is shared by all PCs, then the AS/400 backs up 
everything that is on the "M" drive.  I have used that approach, but do not 
like it because as far as the AS/400 is concerned, the "M" drive is a 
single object ... it can restore the whole thing, we not have granularity 
on addressing only where the problem is, like recovering parts of a normal 
AS/400 backup.  There are advantages here by having a standard backup 
method for what on all PCs in company network.

If you have sufficient disk space, you can designate one AS/400 to be 
handling the backups.  You give it a high caliber backup system.  The other 
computers in the network can save to disk files (check out *SAVF) and can 
do this in like 5 minutes using a check pointing system, so there is 
minimal disruption to their operations, then the backup AS/400 copies those 
backup disk files to tape or whatever, and when done, no longer needs the 
*SAVF files ... so it might take 5 minutes to get the *SAVF, then the 
AS/400 that created it goes on about its business, while the backup might 
take 2 hours to get that to tape, then is ready for *SAVF from another 
computer in the network.

> Good Morning
>
> The company that I work for has a large tape backup system for various
> Windows systems that are installed.
>
> I was asked if there was a similar system available for the AS400.
>
> We are a managed services company and there are multiple AS400 located at
> our facility. All these systems are on different networks. They would like
> to install one large tape backup system that all AS400 can access in order
> to reduce the different type of tapes and cost is a factor also.
>
> Is this a good idea?
>
> Is it possible?
>
> Where would I look to find a tape system?
>
> I appreciate all comments.
>
> Thanks in Advance
>
> Dave Willenborg
> FNTS
> Omaha, Nebraska
>
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