UNIX for Dummies Questions & Answers

Hello everyone,

I like to start off by saying thank-you all. You guys have saved my butt alot of time. Well I have a problem in which I can't find in the search.

I'm trying to do a tar backup to a DDS3 tape as root:

tar -cvf /dev/rmt/0 /home/larry

the error

tar: /dev/rmt/0ermission denied

I've noticed that even in the /etc/mail directory I can't tar to tape. I get the same error.

I don't understand this. I can extract files from the tape and I have no problem using tar. I can also do an ufsdump to tape.
I have also check the tape via mt -f /dev/rmt/0 status. I get the info of the tape.

anyone THANKS

Ever figure this one out?

I read it when first posted but could not think of anything (the fact that you could extract was weird).

Could it be that there has been a change (by someone) to set it up that you can no longer create tars? That or the tar command itself is corrupt. What OS? What is the output of sum or checksum on the tar executable?

I would definitely restore the tar exe from a trusted source. The fact that you can use it and extract with it but not create is weird?

I would look on the web at www.itrc.hp.com --> click on Search. This is for HPUX but there might be an answer there for a generic question regarding tar errors.

I dunno if this is applicable...

But is it possible that somebody as root might have chmod'd the device node so that it could read, but not write?

Wow! Very good Auswipe. You really are WIDE AWAKE today!!

I would give you a gold star... but I am all out...

BTW, I hope that is it, because that is a weird problem.

Yeah. We tain't as fancy as them folks in Plano, but we WIDE AWAKE out here in Wylie! Yeeeeehaw!

Now I feel cheated...

I might try to duplicate this problem later on tonight after dinner. I have an Exabyte 8505XL hooked up to my FreeBSD machine and I can change the permissions and see what happens.

Actually, re-reading the original message I see:

So if Larry is really performing this as root, then the permissions shouldn't matter. The next step would be checking if particular DDS3 tape has write protection enabled.

I have a DDS2 4mm 120 meter tape sitting in front of me and there is a write protect tab that can be switched on and off.

Stranger things have happened...