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8. Tape drives

8.1 ftape

ftape is the original floppy tape driver for Linux and now supports a wide variety of floppy tape drives and a few enhanced controllers. In the later development kernels, ftape is part of the kernel source tree. It is still available separately for those running older kernels. I am not referring to ftape version 3 or above in this section. If you are using ftape version >= 3, for the purposes of this documentation, you should assume that you are using zftape.

Start taper with the -T ftape option.

The device names are /dev/ftape (which should point to /dev/rft0) for the rewinding device, and /dev/nftape (which should point to /dev/nrft0) for the non-rewinding device. These are the values that taper uses as defaults; if your devices are different, modify the values using the environment variables, preferences file, or command line (see below).

If you are still using ftape, I would strongly suggest that you update to zftape which is basically ftape with quite a few enhancements which should drastically improve taper performance. If you have multiple volume backups made under ftape, however, you should not upgrade because you will not be able to access volumes other than 1 using zftape.

8.2 zftape

This section also applies to those people using ftape version >= 3.

Start taper with the -T zftape option.

This driver supports several modes - one is the generic ftape mode. The second is a QIC compliant mode (zftape) and the third is a compressed QIC compliant mode (czftape). It is possible to access archives made with ftape using the generic mode (see below), however, if you make a backup using the QIC compliant mode (zftape), then you cannot use this if you decide to go back to ftape. As this is rarely done, and because the QIC compliant mode is so superior to the generic mode, I would recommend that you use it.

Backups made under ftape will work with zftape if you:

  1. Make sure that you use the device names /dev/ftape and /dev/nftape. You will have to change this manually under Global preferences
  2. You only restore files from the first volume. It is not possible to restore files from other volumes. This is because zftape does not support the fsf ioctl for ftape drives. I am currently corresponding with Claus to see if we can resolve this problem.
  3. Do not try and append data to an archive created with ftape using zftape
  4. You change the set-blksize & get-blksize preferences to yes and change the block-size to 10K. If you have multiple volume backups, then you had best use ftape until you fully migrate all your backups to zftape.

Do not try and make backups with the generic driver of zftape and then go back to ftape and hope that it will work - it won't!

Under taper, the biggest advantage of ztape is the ability to quickly fast forward through archives. You should notice quite a difference, especially when doing a mkinfo and when restoring from multiple volumes. Although zftape has support for compression, you are better off letting taper compress since taper buffers a bit better and has the option of using gzip which is more efficient than the algorithm used by zftape.

The devices for this driver should be created using

make mknod

in the Makefile that comes with the driver. Note that the permissions will be set up so that only root has write access to the tape drive. You will have to change this manually if you want to allow other users access.

The device names are /dev/qft0 for the rewinding device and /dev/nqf0 for the non-rewinding device.

If you make a backup with ftape version >= 3, you cannot restore with zftape.

8.3 SCSI Drives

Start taper with the -T scsi option.

Unfortunately, I do not have a SCSI drive and therefore am unable to test taper code with SCSIs. I rely on SCSI users sending me information about how taper works for them and then I try and use that information to help other SCSI users who are having problems. The following information was sent to me by AP Harris (apharris@onShore.com) and I've included it to help SCSI users.

The SCSI rewinding device is /dev/st0 (or /dev/st1 on the 2nd tape drive) and the non-rewinding device is /dev/nst0. You'll probably have to prepare all your tapes using mktape from the utilies menu.

If you are using a SCSI tape device, make sure you've complied the kernel with SCSI (CONFIG_SCSI) support, SCSI tape support (CONFIG_CHR_DEV_ST) and, of course, support for your SCSI host adapter. If all is well, when you boot, you should see a message like this (your details may vary):

Detected scsi tape st0 at scsi0, id 4, lun 0
scsi : detected 1 SCSI tape 1 SCSI disk total.

No additional drivers are needed (although the st-aware mt is nice).

The block size (-x option below) should be set below the tape device driver buffer size (which can be changed at kernel compile time in the kernel and defaults at 32K).

SCSI tapes generally do not need formatting - see below for full details.

8.4 IDE tape drives

Start taper with the -T ide option.

The default device names are /dev/ht0 and /dev/nht0. Support for IDE drives is in alpha stage and I would encourage users to give me feedback on how taper is working with their IDE drives

8.5 Floppies and other removable media

Start taper with the -T removable option.

When the floppy (or whatever) is full, taper will prompt you for the next floppy/tape. This works in exactly the same way as multiple tape backups. The default device names are set to /dev/fd0 - ie. the first floppy drive.

If you are using a ZIP drive, then make sure that the whole disk has been partitioned as a Linux native partition then start taper:

taper -T removable -b /dev/sda1

Substitute /dev/sda1 with the device name of your ZIP drive. Note: Your ZIP drive must have one partition only since taper ignores the partition table.


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