VXA2 tape drive only stores 56GB

[Andreas Koepke]

We recently upgraded from a DDS4 tape drive to an IBM VXA2 and are
having problems with the VXA2 only storing 56GB per tape. We are using
X23 tapes which are meant to store 80/160GB.

The server it is installed in runs Windows NT and BackupExec 9.0 Rev
4454. I had to install the Revision 4454 update for BackupExec to get
the drive working (wouldn't recognise the drive).

I have checked the firmware and we are running 210D which is apparently
the latest available.

Has anyone encountered this issue before? I am not sure if the problem
might be with WinNT, BackupExec or the drive itself.

Thank you for your time


Andreas Koepke
IT Manager
WA Business News

 

[Arno Wagner]

We recently upgraded from a DDS4 tape drive to an IBM VXA2 and are
having problems with the VXA2 only storing 56GB per tape. We are using
X23 tapes which are meant to store 80/160GB.

The server it is installed in runs Windows NT and BackupExec 9.0 Rev
4454. I had to install the Revision 4454 update for BackupExec to get
the drive working (wouldn't recognise the drive).

I have checked the firmware and we are running 210D which is apparently
the latest available.

Has anyone encountered this issue before? I am not sure if the problem
might be with WinNT, BackupExec or the drive itself.

Thank you for your time

Maybe the tape drive has a problem and finds ornly s small number of
usable areas? If that is the case, then the amount of data should be
different from tape to tape.

Have you asked IBM support about this>

Arno

 

[Folkert Rienstra]

Under perfect conditions, no doubt, like maximum compressable data
and perfect streaming, without the drive inserting empty spaces.

"* Tape drives that use data compression technology have storage capacity
that will vary depending upon whether the drive is operating in native mode
(without compression) or compressed mode. Although the compression
technology used in IBM tape drives can typically double the amount of
data stored on the media, the actual degree of compression achieved is
highly sensitive to the characteristics of the data being compressed."
http://www-132.ibm.com/webapp/wcs/s...Id=8595139&storeId=1&langId=-1&catalogId=-840

Maybe the tape drive has a problem and finds ornly s small number of
usable areas? If that is the case, then the amount of data should be
different from tape to tape.

Babbling again, babblemouth?

 

[Andreas Koepke]

Maybe the tape drive has a problem and finds ornly s small number of
usable areas? If that is the case, then the amount of data should be
different from tape to tape.

Have you asked IBM support about this>

Arno

The amount of data stored on each tape is pretty much the same. I have
called IBM support and they cannot help me until I give them the model
number of the drive. This will have to wait until the weekend when I can
shutdown the server, take out the drive and get this for them.

I was hoping to find an answer before having to do this.

 

[Andreas Koepke]

Under perfect conditions, no doubt, like maximum compressable data
and perfect streaming, without the drive inserting empty spaces.

"* Tape drives that use data compression technology have storage capacity
that will vary depending upon whether the drive is operating in native mode
(without compression) or compressed mode. Although the compression
technology used in IBM tape drives can typically double the amount of
data stored on the media, the actual degree of compression achieved is
highly sensitive to the characteristics of the data being compressed."
http://www-132.ibm.com/webapp/wcs/s...Id=8595139&storeId=1&langId=-1&catalogId=-840

I can understand the drive not being able to use all 160GB of space
because that relies on compression and the amount of space saved due to
compression varies depending on the data.

The problem here is that the tape isn't even storing its native
uncompressed capacity. 56GB is a lot short of 80GB.

Without any compression involved the drive should be able to store 80GB
worth of space. That is what is being advertised and what we bought it
to do.

 

[Arno Wagner]

The amount of data stored on each tape is pretty much the same. I have
called IBM support and they cannot help me until I give them the model
number of the drive. This will have to wait until the weekend when I can
shutdown the server, take out the drive and get this for them.

I was hoping to find an answer before having to do this.

A thought: If the data is very badly compressible and if the
compression is pretty stupid, it could inflate the size. I
don't think it can be this much, but is your data perhaps
encrypted or precompressed?

Arno

 

[Folkert Rienstra]

A thought: If the data is very badly compressible and if the
compression is pretty stupid, it could inflate the size.

From 160GB to 56GB? Oh Babblemouth.

I don't think it can be this much,

But you babble anyway.

 

[andreas.koepke]

A thought: If the data is very badly compressible and if the
compression is pretty stupid, it could inflate the size. I
don't think it can be this much, but is your data perhaps
encrypted or precompressed?

Arno

I have heard of this sort of thing happening but I doubt it would apply
in this case. I work for a newspaper so lots of the data is images but
not all of them are in compressed formats. Most of the time we use EPS
format which is uncompressed.

Thanks for your help though, hopefully IBM will have something for me
to work with when I call them on Monday.

 

[andreas.koepke]

From 160GB to 56GB? Oh Babblemouth.


But you babble anyway.

How about actually contributing something meaningful rather than just
attacking other people. Have you got nothing better to do than attack
those that are trying to help?

All you are doing is making yourself look petty. Grow up.

 

[Arno Wagner]

How about actually contributing something meaningful rather than just
attacking other people. Have you got nothing better to do than attack
those that are trying to help?

All you are doing is making yourself look petty. Grow up.

That is just Folkert. Don't mind him. His competence is no match for
his ego. For example see above, where he completely misunderstands
the problem and assumes the base capacity for uncompressible files
is 160GB.

Arno

 

[Arno Wagner]

I have heard of this sort of thing happening but I doubt it would apply
in this case. I work for a newspaper so lots of the data is images but
not all of them are in compressed formats. Most of the time we use EPS
format which is uncompressed.

Agreed. Uncompressed EPS is usually pretty well compressible.

Thanks for your help though, hopefully IBM will have something for me
to work with when I call them on Monday.

Good luck.

Arno

 

[Folkert Rienstra]

How about actually contributing something meaningful rather than just
attacking other people.

I did. You ignored it. Presumably you didn't understand the implications.
That's fine.

Have you got nothing better to do than attack those that are trying to help?

Why? Is he trying to help, then? Or is he just posing to be helpful?
Wanna hint: It's the latter. Arnie likes to babble and he takes any opportunity
to do so. Never ever reads his messages back, scared shitless that he would not
dare send them anymore if he did. He also has a well filled killfile so he does't
get confronted with those who might show him all of his stupidity.

All you are doing is making yourself look petty.

Grow up.

Like Arnie? Yes dad, thank you dad.