VFS Device

Introduction

Since release 2.4.3, Amanda supports the usage of a VFS Device, with prefix "file:".

As the name suggests, this driver uses files on disk as virtual tapes. Amanda can write to and read from virtual tapes, just like real tapes. A bunch of virtual tapes can even be manipulated with a changer.

Possible Uses

• Disk-based installations: You can use the file driver to backup onto a set of virtual tapes hosted on a bunch of hard-disks or a RAID-system. Combined with another Amanda configuration that dumps the virtual tapes to real tapes, you can provide reliable backup with faster tapeless recovery. This is called "disk-to-disk-to-tape" backup by some people today.

• Inexpensive installations: Without buying a tape drive you can enjoy the benefits of Amanda and backup to a bunch of harddisks. You can create CD/DVD-sized backups which you can burn onto optical disks later. Or you can backup to external disks connected with Firewire or USB.

• Test installations: You can easily explore the rich features of Amanda on systems without tape drives. Virtual tapes are usually also much faster than many real tape drives. For a quick start, have a look at: Test environment with virtual tapes.

Please be sure to understand the differences between holding disks and virtual tapes. The two serve different purposes; holding disks allow for parallelism of multiple disklist entries (DLE's) being backed up while virtual tapes are a replacement for physical tapes.

The virtual tapes are also called "vtapes" in this document.

Using Virtual Tapes

A virtual tape is implemented as a directory with a subdirectory named "data" in it.

# chown amanda:disk /amandatapes
# chmod 750 /amandatapes                       # backups contain secret files!
# su - amanda
$ mkdir -p /amandatapes/test/tape1/data

You can check a vtape using amdevcheck (available in version 2.6.0):

amdevcheck MYCONFIG file:/amandatapes/tape1

and can also label vtapes just like any other kind of tape:

amlabel MYCONFIG CONFIG017

Note that vtapes work well with chg-disk.

See Also

• How To:Set Up Virtual Tapes

Credit

Based on text by: Stefan G. Weichinger, November - December, 2003 ; minor updates in April, 2005.