Selecting a Backup Medium

Using ftape tools for magnetic tape

If your tape drive is attached to an IDE floppy controller cable, you will need to use the ftape driver to access it. Fortunately, version 3.04d of the ftape loadable module is bundled with the Linux 2.4 kernel. When your Linux system boots, it should autodetect the tape drive and load the ftape driver. To verify that your system loaded the tape driver, type the following command shortly after you boot your computer:

dmesg | grep ftape

This searches the most recent kernel messages for lines containing the word ftape. If the ftape module was loaded, you should see something like this:

ftape v3.04d 25/11/97
[000] ftape-init.c (ftape_init) - installing QIC-117 floppy tape
hardware drive... .
[001] ftape-init.c (ftape_init) - ftape_init @ 0xd08b0060.
[002] ftape-buffer.c (add_one_buffer) - buffer nr #1 @ c1503914, dma
area @ c02c0000.
[003] ftape-buffer.c (add_one_buffer) - buffer nr #2 @ c1503c44, dma
area @ c0298000.
[004] ftape-buffer.c (add_one_buffer) - buffer nr #3 @ c50abaac, dma
area @ c0328000.
[005] ftape-calibr.c (time_inb) - inb() duration: 1109 nsec.
[006] ftape-calibr.c (ftape_calibrate) - TC for `ftape_udelay()' = 310
nsec (at 20479 counts).
[007] ftape-calibr.c (ftape_calibrate) - TC for `fdc_wait()' = 2208 nsec
(at 2559 counts).

If the module was not loaded, then you should check if your kernel is compiled with support for the ftape module and your particular tape drive. Refer to the section on reconfiguring the kernel located in Appendix A. When running the make config or make xconfig command, choose Character Devices ? ftape, the floppy tape device driver. You can then verify that the ftape module is enabled and that your specific hardware is supported. Continue with compiling and installing the kernel in the normal way.

In most cases, an ftape device can be accessed just like a SCSI device. The primary difference is that an ftape device file contains the letters qft (for QIK Floppy Tape) where a SCSI tape contains st. For example, the device file for the first SCSI tape on your system will probably be /dev/st0; the device file for the first floppy tape will likely be /dev/qft0.

All of the standard tape and archiving related programs should work fine with both types of hardware. Nevertheless, there are a few extra programs that you may find useful when working with a floppy tape drive. These programs can be found in the ftape-tools package located at ftp://metalab.unc.edu/pub/Linux/kernel/tapes/. Download the file named ftape-tools-1.09.tar.gz. If a version higher than 1.09 is available, download that instead. Extract the ftape package using the tar command:

$ tar -xzvf ftape-tools-1.09.tar.gz

This extracts the package into an ftape-tools-1.09 directory. Use the cd command to go to that directory and to run the ./configure script to prepare the package's makefiles. Next, compile the package by typing the make command:

$ ./configure
$ make

Finally, assume root privilege using the su command and type make install to install the ftape-tools programs and online man pages to the appropriate directories:

# make install

Testing the magnetic tape drive

You should now be ready to test your tape drive. Insert a blank tape into the tape drive and type the following command:

$ mt -f /dev/qft0 rewind

You should hear the tape spin as the system rewinds the tape. This will be a very short process if the tape is already rewound. The mt command provided with ftape-tools is used to scan, rewind, and eject magnetic tapes in a floppy controller tape drive. It is very similar in operation to the st command, which is used to perform the same functions on SCSI tapes.

Formatting magnetic tapes

The ftape-tools package also includes a tool for formatting tapes as well. Most tapes now come preformatted. In the event that you have an older floppy controller tape drive that uses unformatted tapes, use the ftformat command to format them:

$ /usr/local/bin/ftformat -f /dev/qft0

Usually, the -f parameter with the device name is the only parameter that you need to supply. Nevertheless, you are encouraged to read the online man page for ftformat to learn more about its options and capabilities.

Getting cdrecord for writable CDs

To write CDs with Red Hat Linux you need to install the cdrecord package. This package contains components such as the cdrecord, devdump, isodump, isoinfo, isovfy, and readcd commands. The cdrecord package is included with the Red Hat Linux distribution.

Writing to CDs

Because the data written to a CD becomes permanent once it is written, you need to format the CD and copy files to it all in one step. If you formatted it first, you would end up with an empty file system on a CD that can no longer be written to.

The first step is to create an image of the CD file system as a file on your computer. You do this with the mkisofs command. As an example, imagine that you want to back up the home directory for user mary. You would invoke the mkisofs command and pass it the name of the file system image file to create, followed by the directory to base it on:

$ mkisofs -R -o /var/tmp/mary.cd /home/mary

This creates an ISO9660 file system image in a file named mary.cd located in the /var/tmp directory. The –R option causes Linux-specific file ownership and long file names to be used. If your /var partition does not have enough room for the image, choose a different location.

Before you can write this image file to a CD, you must first discover the SCSI bus number, device ID number, and Logical Unit Number (LUN) of the CD drive. Unless you have an actual SCSI bus in your computer, the emulated SCSI bus is probably numbered zero. You can find out which SCSI device ID the CD drive is using. Invoke the cdrecord command with the single parameter -scanbus:

# cdrecord -scanbus

You should see a response similar to the following:

Cdrecord 2.0 (i686-pc-linux-gnu) Copyright (C) 1995-2002 J?rg Schilling
Linux sg driver version: 3.1.25
Using libscg version 'schily-0.7'
scsibus0:
        0,0,0     0) 'IDE-CD ' 'R/RW 4x4x24  ' '1.04' Removable CD-ROM
        0,0,1     1) *
        0,0,2     2) *
        0,0,3     3) *
        0,0,4     4) *
        0,0,5     5) *
        0,0,6     6) *
        0,0,7     7) *

This tells you that the CD drive is using SCSI ID zero. The Logical Unit Number in this case should always be zero, so you now have all three numbers. You supply them to cdrecord as part of the dev parameter. The SCSI bus number is listed first; it is followed by the ID number, and then by the LUN. The entire command should look similar to this:

# cdrecord -v speed=2 dev=0,0,0 -data /var/tmp/mary.cd

Several additional parameters are included in the command. The -v parameter tells cdrecord to supply verbose output to the screen. The speed parameter tells cdrecord what speed to record at (in this case X2). (You might choose to leave off speed=2 and let cdrecord autodetect the record speed of your CD burner.) The -data parameter tells cdrecord that the next parameter is the name of the file system image to write to the CD. (You can add the -eject to eject the CD when it is done.) As it works, cdrecord should display status messages that look similar to the following:

Cdrecord 2.0 (i686-pc-linux-gnu) Copyright (C) 1995-2002 J?rg Schilling
TOC Type: 1 = CD-ROM
scsidev: '0,0,0'
scsibus: 0 target: 0 lun: 0
Linux sg driver version: 3.1.24
Using libscg version 'schily-0.7'
atapi: 1
Device type    : Removable CD-ROM
Version        : 0
Response Format: 1
Vendor_info    : 'IDE-CD'
Identifikation : 'R/RW 4x4x24        '
Revision       : '1.04'
Device seems to be: Generic mmc CD-RW.
Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
Driver flags   : MMC SWABAUDIO
Supported modes: TAO PACKET RAW/R16
Drive buf size : 1572864 = 1536 KB
FIFO size      : 4194304 = 4096 KB
Track 01: data   322 MB
Total size:     370 MB (36:43.12) = 165234 sectors
Lout start:     370 MB (36:45/09) = 165234 sectors
Current Secsize: 2048
ATIP info from disk:
  Indicated writing power: 4
  Is not unrestricted
  Is not erasable
  Disk sub type: Medium Type A, high Beta category (A+) (3)
  ATIP start of lead in:  -11849 (97:24/01)
  ATIP start of lead out: 359848 (79:59/73)
Disk type:    Long strategy type (Cyanine, AZ0 or similar)
Manuf. index: 25
Manufacturer: Taiyo Yuden Company Limited
Blocks total: 359848 Blocks current: 359848 Blocks remaining: 194614
Starting to write CD/DVD at speed 2 in real TAO mode for single session.
Last chance to quit, starting real write in 0 seconds. Operation starts.
Waiting for reader process to fill input buffer ... input buffer ready.
Performing OPC...
Starting new track at sector: 0
Track 01:  322 of  322 MB written (fifo 100%)  [buf  99%]   2.0x.
Track 01: Total bytes read/written: 338395136/338395136 (165232 sectors).
Writing  time:  1110.710s
Average write speed   2.0x.
Fixating...
Fixating time:  126.108s
cdrecord: fifo had 5331 puts and 5331 gets.
cdrecord: fifo was 0 times empty and 5262 times full, min fill was 96%.

After cdrecord finishes writing the CD and your shell prompt returns, delete the file system image file /var/tmp/mary.cd. Label the CD appropriately and store it in a safe place.

If you need any files that were copied to the CD, just return the CD to the CD drive. If it doesn't automatically open a window displaying the contents of the CD, type: mount /mnt/cdrom as root user. Open /mnt/cdrom in a folder window and copy the files you want.