HP 1533A maximum size ?

[Vijay Kumar_5]

We have a HP 1533A Tape device and 4/8 GB
Tapes. Currently we are unable to take a
backup of 3.8 GB on the tape. The error given
is :

" The current media is full and there is no
free media. Please add media or cancel to stop
the operation. "

I am not able to understand why this is
happening ? No proper error messages ?
I believe the Tape can store 4 GB data without
compression and 8 GB with Hardare Compression.

Kindly help me solve this issue.

Vijay Kumar.

[Oliver Charni]

Hi!

what Backup software do you use ?
the actual ammount of data that can be written to the tape also depends on the what kind of files you save(eg. a few large files, or lots o small ones etc.).

regards
oliver

[Leif Halvarsson_2]

Hi,
Check what kind of media do you use. Uou must use DDS 2 media to reach 4/8 GB capacity. The drive is also compatible with DDS 1 medias but this media will store only 2/4 GB.

[V.Tamilvanan]

Hi,
There would be a switch setting to enable Hardware compression on the Tape Device. Check it out.

[Vijay Kumar_5]

Hi,

Thanks for all the answers. I am using the
DDS2 tapes.
The sofwtare used is NTBackup on a Windows
2003 server. The backup size is still below
4 GB which should not require compression
and yesterday I even tried a 3.5 GB backup
which also failed. Hence I dont think the
hardware compression is an issue. Still,
could someone point me to a URL which talks
about the switch settigs on the tape for
hardware compression ? I shall enable it if
its not enabled. Also is the switch is set
right, what would be the other options ?

Kindly help me with your suggestions, I need
to resolve this as sson as possible.

Regards,
Vijay Kumar.

[Dave Dewar]

Hi,

There could be a couple of reasons why you are seeing this.

1. You are backing up already compressed data (either you have software compression turned on within your backup app - I don't think NTbackup supports this though, or your data consists of jpegs, zip files and other compressed data) and you have hardware compression turned on and the compression engine within the drive is actually expanding the data somewhat. Trying to compress already compressed data can result in data expansion on some tape drives.

2. You drive is have some problems writing and so is uses up more capacity to rewrite your data to ensure you can read it back. All HP DDS drives include "read after write" by default and will rewrite bad data until they have satisfied themselves that the data is readable or they reach a write retry limit.

3. Your backup app is making use of a feature in DDS called "N group writing" which will rewrite data multiple times by default. I don't no of anyone who actually uses this, but anthing is possible with Microsoft :). I think this is very unlikey to be the case but I list it for completeness.

It would be very useful if you could download LTT (library and tape tools) and run it on your drive and post the support ticket here so we can see the health and status of your drive, including your hardware compression status. If you generate the ticket with the tape you are using loaded that would be most helpful.

You can download LTT from the link below:

http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?pnameOID=12574&locale=en_US&taskId=135&prodSeriesId=63916&prodTypeId=12169&swEnvOID=1005


Cheers,

Dave Dewar

[Vijay Kumar_5]

Hi,

I have installed the Tape Tools and attached
is the htm file generated by the ticket.

a) Yes I have data which is already zipped.
Out of 3.5 GB of data approx , 2.5 GB
data is a compressed .bz2 data file. Even
I could not find any option of software
compression in NTBackup. But the point
is:
i) The drive should be able to write 4 GB
of data with using hardware compression.
Will it have any problems in doing so ?

b) I have tried the ticket test with
about 4-5 different media tapes, but the
warning in section 2.1 still persists.
( You have media errors logged in your
drive ) Is there some problems in
all the media's, or there is some problem
in the tape.

c) I think as per the ticket information,
hardware compression is not enabled.
Let me know to enable it ?

Regards and thanks a lot for the help
offered.

Vijay Kumar.

[Dave Dewar]

Vijay,

See my comments below.

>I have installed the Tape Tools and >attached is the htm file generated by the >ticket.

Can you please save the ticket in ltt format and zip it up and attach it here. Your html file was generated at "normal" output mode and so is missing a lot of extra info. Plus the full ticket in ltt format contains factory only hidden info that is useful for debugging issues.

>a) Yes I have data which is already zipped.
>Out of 3.5 GB of data approx , 2.5 GB
>data is a compressed .bz2 data file. Even
>I could not find any option of software
>compression in NTBackup. But the point
>is:
>i) The drive should be able to write 4 GB
>of data with using hardware compression.
>Will it have any problems in doing so ?


If the majority of your data is already compressed you will gain nothing by turning on hardware compression and you could end up expanding your data somewhat. Trying to compress already compressed data can have that effect. Hence your 2.5GB compressed data file could increase in size when it is backed up on tape.
The drive should be able to write 4GB of data to tape with compression turned off, unless the drive is having difficulties writing and so is having to perform rewrites to ensure the data is readable. Rewites waste tape, the drive does not go back to rewrite the data, it keeps writing the same data until it succeeds.

>b) I have tried the ticket test with
>about 4-5 different media tapes, but the
>warning in section 2.1 still persists.
>( You have media errors logged in your
>drive ) Is there some problems in
>all the media's, or there is some problem
>in the tape.

Ok, it does appear that you could have a writing issue. I would need to see the full support ticket to confirm this. Have you used a cleaning tape as suggested? You can run some write and read tests using LTT that would check whether your drive has a good error rate when writing and reading data. I would recommend you do this. Post your results here.

>c) I think as per the ticket information,
>hardware compression is not enabled.
>Let me know to enable it ?

The link below describes the function of the switches on the bottom of the product.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?locale=en_US&taskId=120&prodSeriesId=63916&prodTypeId=12169&objectID=lpg51068

Switches 1 and 2 control how data compression is enabled and controlled by host. You currently have switch 1 and 2 set to on and so have data compression enabled and under host control so it appears that your host is disabling data compression for you. Setting switch 2 to off will enable data compression without host control, it will always be on.

>Regards and thanks a lot for the help
>offered.

An additional resource you can use for troubleshooting issues is the online troubleshooting guide at the following link:

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00057819&locale=en_US#read

>Vijay Kumar.

Cheers,

Dave Dewar