Reading 4MM/8MM tapes from different platforms?? 1

[melville]

Is there some guide out there if you have problems reading 4MM and/or 8MM tapes from different platforms?? i.e.

Received from a: Read on a:
SUN (4MM) HP (4MM)
HP (4MM) SUN (4MM)
IBM (8MM) SUN (8MM)
SUN (8MM) IBM (8MM)
SGI (4MM) SUN (4MM)
SUN (4MM) SGI (4MM)
WINDOWS NT (4MM) SUN (4MM)
SUN (4MM) WINDOWS NT (4MM)

I know this is old technology, but any help and/or reference would be appreciated!!

Have a great day!! d:-D
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[AndyBo]

What kind of problems are you getting? What format were the tapes created in? (tar, cpio?) [sig]<p> Andy Bold<br><a href=mailto: > </a><br><a href= > </a><br>"I've probably made most of the mistakes already, so hopefully you won't have to..." Me, most days.[/sig]

 

[melville]

Andy Bold -

Thanks for the quick response, I get tape read errors while performing the &quot;tar xvf /dev/rmt/0&quot; command. I find that certain tape devices will extract the data, others won't???

Should I be using a different command like &quot;cpio&quot; or &quot;dd&quot;.

We have Solaris workstations at our site running Solaris 2.7.

We don't have CD-ROMs so we are sort of stuck with 4MM/8MM tapes. The tape devices are fairly new.

Any more questions??????

Sincerely,

Mel Kennedy [sig][/sig]

 

[sun23]

r u trying to extract to a read only filesystem viz CDROM?
ru sure it is /dev/rmt/0 not /dev/rmt/1 etc?
how about rewinding the tape before operation
whether all backups are in tar format. (Not in ufsdump or something else).
Whether the tape is corrupted?
Have you checked the tape drive?It may be defective!
Hope this helps
Sun
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[melville]

sun23 -

Thanks for your quick response!!

Every once in a while we will get a 4MM tape from a supplier an we get a tape read error.

- we check to make sure the tape is not defective
- if we get permission/read errors or links (you would be surprise what we get) the tape is sent back
- WE WILL START REWINDING THE TAPE PRIOR OPERATION - GOOD IDEA
- we had all tape drives replaced by Sun within the past year
- we are using the correct device, /dev/rmt/0 is for the 4MM, /dev/rmt/1 is for the 8MM
- WE ALL EXTRACT USING &quot;LOW DENSITY&quot;

Sincerely,

Mel Kennedy
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[cassim]

Hi,

Try the following, assuming you used the &quot;tar&quot; command to backup.

dd if=tape_device_name conv=swab| tar -tvf - (to read tape)
dd if=tape_device_name conv=swab| tar -xvf - (to extract tape)


I used this a long time ago to read tapes between a unisys unix machine and a SCO unix machine.

Hope this helps
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[AndyBo]

Something else to be aware of is hardware compression. A long time ago, in a job far, far away, we were sending out tapes to customers that had been created on a DDS2 drive on an IBM AIX server. The customers were using exactly the same servers and tape drives. After some in-depth checking, we found that in the &quot;smit&quot; settings for the customer's tape drive, they had disabled the hardware compression, whereas we were still using it.

Unfortunately, I can't remember the exact smit options that were used...

We didn't have problems on other non-IBM servers, as these tended to use different device names to specify compression, etc.

Just a stab in the dark, but I hope it helps. [sig]<p> Andy Bold<br><a href=mailto: > </a><br><a href= > </a><br>"I've probably made most of the mistakes already, so hopefully you won't have to..." Me, most days.[/sig]

 

[VIKINGS]

I cut 4mm tapes for customers on an HP-UX box. One customer on a SCO box cannot read the tapes. Maybe the older tape drive can not handle 4 gig. We believe it is somehow compressed or not in the same format.
Using cpio -ocvB to write. Any ideas?