Default variables: configuration

some of debops.tgt default variables have more extensive configuration than simple strings or lists, here you can find documentation and examples for them.

tgt_targets

This is a list of iSCSI Targets configured on the host. Each iSCSI Target can have multiple backing stores with custom configuration. Examples of options which can be passed to the tgt configuration can be found in /usr/share/doc/tgt/examples/targets.conf.example.gz.

List of recognized iSCSI Target parameters:

name
Required. Target name, added after tgt_iqn_base string, used also as the filename of the configuration file in /etc/tgt/conf.d/*.conf if item.filename is not specified.
filename
Alternative name of the configuration file.
iqn
Custom IQN string used instead of the default one.
options
tgt options added to a given target, in YAML text block format.
backing_stores
List of volumes present in a given iSCSI Target (see below).
direct_stores
List of “passthrough” volumes present in a given iSCSI Target (see below).
delete
If present and True, this iSCSI Target configuration will be removed from the configuration directory; if a given target is not used at the moment of deletion, it will also be removed from the server.

iSCSI backing/direct stores

To provide a given volume through iSCSI, you need to specify it in a given target as either a backing-store or direct-stre. Direct stores read some metadata from storage devices and are more suited to export real hardware storage media, backing stores are more suited to export logical volumes, block devices or files.

To configure a set of stores, you can specify them directly in item.options parameter:

tgt_targets:

  - name: 'hostname.data'
    options: |
      backing-store /dev/sdc
      backing-store /dev/sdd

There are also available separate lists, backing_stores and direct_stores. Using these, you can specify a YAML list of block devices or files to add to the iSCSI Target:

tgt_targets:

  - name: 'hostname.data'
    backing_stores: [ '/dev/sdc', '/dev/sdd' ]

If you need to specify additional per-store options, you can specify them as dicts instead:

tgt_targets:

  - name: 'hostname.data'
    backing_stores:

      - store: '/dev/sdc'
        options: |
          lun 1

      - store: '/dev/sdd'
        options: |
          lun 2

Warning: you need to make sure to only use one of these definition types in an iSCSI Target, ie. either a simple list of stores or a list of dicts which define stores. Never mix them, otherwise the tgt configuration parser won’t be able to correctly parse the configuration files.

Other examples

How to create an iSCSI Target with an image file presented as a CD/DVD drive:

tgt_targets:

  - name: 'install.debian.wheezy'

    backing_stores:
      - '/srv/tgt/image/install/debian-7.8.0-amd64-i386-netinst.iso'

    options: |
      device-type cd
      readonly 1
      MaxConnections 10