DAT24e tape recorder

[Ray_16]

I am using DAT24e tape recorder with Backup Exec v7.3 on NT4 server. I use 24 GB tape but only achieve close to 12 GB by setting hardware compression (if any, otherwise software compression) in Backup Exec. Can someone tell me how to get 24 GB storage space as claimed.

Thanks,

Ray

[Rothery Harris]

Dear Ray,

The 24GB capacity is based on an assumed compression ratio of 2:1. There are two posiibilities here:
1. Your data is highly random and cannot be compressed at all.
2. HW compression is not turned on within Backup Exec.
3. The switches on the base of the drive mechanism have been changed. This is unlikely on an external drive as they are not accessible unless the drive mechanism is removed from the enclosure. The 'default' setting is switch 3 = OFF and all other switches 'ON'. This allows hardware compression to be set by the host.

Rothery

[Ray_16]

Hi Rothery,

Thanks for your reply.

I tried to use HP Library and Tape Tools to find out if the compression has been disabled without success. Tools report failure to connect to the device and has a red cross on the tape icon. The firmware version is 708. I checked the HP site and discovered a new firmware L111 for use with HP Library and Tape tools. I downloaded it but cannot install it. I double clicked the downloaded file but it asked me the software to open the file - it is quite adnormal to normal firmware upgrade. Do you have any idea to install the upgrade?

Thanks,

Ray

[BR659932]

Hiya.

For compression settings, check the DIP switches on the drive. They should show Switch 3 off, all the rest on.

Most likely reason for L&TT failing to connect to the drive the way you described is that you have backup services running, so stop them all first and try again.

To update the FW, move it to directory C:\Program Files\HP Library & Tape Tools\logs and use L&TT for update. Double-clicking doesn't do anything for those files, if they are in .frm-format. .exe-file will only get unpacked.

HTH,
~A~

[Ray_16]

Many thanks for useful advice. Now I upgraded the tape recorder to the latest version firmware successfully.

I have learnt that L&TT shows the compression status but it does not. Probably, I need to verify it by removing the cabinet and check the DIP switches.

With the latest firmware, the OBDR is present. I checked the latest drivers for dat24e on HP website and discovered the BIOS for SCSI card should have the support for OBDR. My Adaptec SCSI card is Adaptec AHA-2940AU that comes with HP LC3 server. There is no BIOS for my SCSI model on the website. I think this is special support for HP DAT rrecorder. Without the upgraded BIOS, is it possible to use OBDR?

Finially, where I can obtain the user manual for OBDR? I believe this feature was introduced after my purchase of the recorder.

Thanks,

Ray