Tape drive and tapes

[boomerang]

Hi Admins,

How can get the details of tape drive?
How can get the size/attributes of of tape inserted ?

Please share a doc for Tape drive adminstration.

[Johnson Punniyalingam]

How can get the details of tape drive?

ioscan -fnC tape

How can get the size/attributes of of tape inserted ?

# diskinfo /dev/rmt/0m
SCSI describe of /dev/rmt/0m:
vendor: HP
product id: C1537A
type: sequential access
size: 1161216 Kbytes
bytes per sector: 1024

[Ismail Azad]

Hi,

Every tape drive will have a device file associated with it and tape drives will not have block device files as they are serial devices that is why you will never see a tape drive with /dev/mt or /dev/tape. You will only see /dev/rmt.. /dev/rtape.. lssf command followed by the device file will give device specific access options which are most useful for tape drives. lssf will give you whether you are using AT&T or berkley style, if the no rewind bit is set or if the tape drive has to be written on to only after the write on to it has been completed, technically called as {immediate report disabled}. This would work on 11.31. Hope that's the O.S you have.

Regards
Ismail Azad

[pradeep m · Accepted solution]

To add to this, you can also use the "mt" command to administer the tape drive in HP-UX.

Refer the attached document (HP-UX Tape Drive Reference Hand Book.doc) for your reference.

Thanks,
Pradeep

[boomerang]

Thanks to all 4 your inputs.

Pradeep,

Thanks a lot for a simple doc.It is very helpful for a beginner like me.


Can sumbody help me to check how much space is utilized in the tape ? how can we write the new data at the end of last data in tape?

[Dennis Handly]

>how can we write the new data at the end of last data in tape?

What tool are you using to do that? tar/pax/cpio?

Typically this is very dangerous, how do you remember how many EOFs to skip?

[boomerang]

Dennis,

I usually use tar,never used pax or cpio which is the best in it ? which situation is the pax or cpio best served.

Can you suggest me the best practices for tape & tape drive adminstration

[pradeep m]

Both cpio and tar are implemented as links to pax, which is capable of reading and writing both cpio and tar formats. Both cpio and tar are common on UNIX systems. The pax utility is a cover utility for cpio and tar, so it doesn't support its own archive format. By default, pax will use the tar format when creating an archive.
In HP-UX 11.31, the pax utility uses it own pax archive format.

The pax utility will detect when you've reached the end of a disk or tape on a volume and will prompt you to insert the next volume to be used for the save. The result is a backup spanning several media (disks, tapes, etc.).

[Dennis Handly]

>which is the best in it? which situation is the pax or cpio best served.

pax has a better interface, combining tar and cpio. It's also able to write bigger files.

>Can you suggest me the best practices for tape & tape drive administration

You don't bet your company on using tar/pax/cpio, you use a commercial product.
Or fbackup(1m), which will be obsoleted in the future. (Which doesn't let you append to a tape.

>pradeep: Both cpio and tar are implemented as links to pax,

Huh? I don't see those.

>which is capable of reading and writing both cpio and tar formats

Right.

>so it doesn't support its own archive format.

pax also supports "-x pax", if you have installed PAX-ENH.

[boomerang]

Thanks to all for you valuable time and suggestions.Points assigned.