file on tape

UNIX for Advanced & Expert Users
1

Hi,
I use the following commands on Solairs to backup my Oracle db file to tape:
mt -t /dev/rmt/0 rew
exp ..... file= /dev/rmt/0n

Q1:
how can I copy this file back onto my disk? (ufsrestore doesn't work)

Q2:
I found that /dev/rmt/0n is linked to /devices/ssm@0,0/pci@1d,600000/pci@1/SUNW,isptwo@4/st04,0:n and the size of that file shows 33279. This filesize seems too small for my database file. So what does this number mean?
(btw, I got the number 33279 by ls -l /devices/ssm@0,0.......)

Thanks.
James.

2

Its not clear to with backup command you are using.

When you want to restore with `ufsrestore` you need to make your backup with `ufsdump`

The file you mentiond in Q2 is NOT the database file, it is just the tape device.

`mt -t /dev/rmt/0 rew` is just doing a rewind of your tape.
`exp ..... file= /dev/rmt/0n ` I do not know what you mean with this.

Hereby the man page of ufsdump/ufsrestore

3

Sorry that my wording 'backup' was misleading.

My ex-co-worker extracted some data in an Oracle database by using the Oracle "exp" utility and directly write data onto the tape device(hence the command exp ....... file=/dev/rmt/0n ....).

by looking at the script I thought the data would be stored in the filename /dev/rmt/0n, which is the same as the tape device, so I try 'cp' it but it didn't work. Is there a default filename for data stored on the tape device? I want to copy the file back to a disk to I can ftp it to somewhere else.

Also, I did a 'ls -l /dev/rmt/0n' and it showed a link to /devices/ssm@0,0/pci@1d,600000/pci@1/SUNW,isptwo@4/st04,0:n and then I did a 'ls -l ' on the file and it showed 33279 as the filesize. Does this number represent how much data that is currently stored on the tape device?

Thanks.

4

Hi,

You can use the `dd` command to read blocks from tape to disk.
hereby the SUN manpage of dd