Alpine iSCSI Target

Table of Contents

Lets share a file base iSCSI disk from Alpine.

The targetcli

Man page description:

targetcli is a shell for viewing, editing, and saving the configuration of the kernel’s target subsystem, also known as LIO. It enables the administrator to assign local storage resources backed by either files, volumes, local SCSI devices, or ramdisk, and export them to remote systems via network fabrics, such as FCoE.

Install in Alpine

apk add targetcli
rc-update add targetcli

Start System Service

service targetcli start

targetcli shell

targetcli work like a directory tree and you can use ls to list the management structure.

# targetcli
targetcli shell version 2.1.fb49
Copyright 2011-2013 by Datera, Inc and others.
For help on commands, type 'help'.

/> ls
o- / ...................................... [...]
  o- backstores ........................... [...]
  | o- block ............... [Storage Objects: 0]
  | o- fileio .............. [Storage Objects: 0]
  | o- pscsi ............... [Storage Objects: 0]
  | o- ramdisk ............. [Storage Objects: 0]
  o- iscsi ......................... [Targets: 0]
  o- loopback ...................... [Targets: 0]
  o- sbp ........................... [Targets: 0]
  o- vhost ......................... [Targets: 0]
  o- xen-pvscsi .................... [Targets: 0]
/>

Create iSCSI Target

We will use the targetcli shell mode to create a file base iSCSI target.

Backstore

Lets create a 10G disk in /tmp.

/> cd backstores/
/backstores> cd fileio
/backstores/fileio> create disk01 /tmp/disk01.img 10G
Created fileio disk01 with size 10737418240

We can also do it as follow and get the same result:

/> backstores/fileio create disk01 /tmp/disk01.img 10G

We will use this shorthand from here on.

Let do a ls

/> ls
o- / ......................................................... [...]
  o- backstores .............................................. [...]
  | o- block .................................. [Storage Objects: 0]
  | o- fileio ................................. [Storage Objects: 1]
  | | o- disk01 . [/tmp/disk01.img (10.0GiB) write-back deactivated]
  | |   o- alua ................................... [ALUA Groups: 1]
  | |     o- default_tg_pt_gp ....... [ALUA state: Active/optimized]
  | o- pscsi .................................. [Storage Objects: 0]
  | o- ramdisk ................................ [Storage Objects: 0]
  o- iscsi ............................................ [Targets: 0]
  o- loopback ......................................... [Targets: 0]
  o- sbp .............................................. [Targets: 0]
  o- vhost ............................................ [Targets: 0]
  o- xen-pvscsi ....................................... [Targets: 0]
/>

iSCSI

Target

We have to create an iSCSI target:

/> iscsi/ create
Created target iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319.
Created TPG 1.
Global pref auto_add_default_portal=true
Created default portal listening on all IPs (0.0.0.0), port 3260.

The iscsi/ create automatically created the following:

  • WWN: iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319
  • Portal group: tpg1 and the portals 0.0.0.0:3260

    /> ls
    o- / ..................................................................... [...]
    o- backstores .......................................................... [...]
    | o- block .............................................. [Storage Objects: 0]
    | o- fileio ............................................. [Storage Objects: 1]
    | | o- disk01 ............. [/tmp/disk01.img (10.0GiB) write-back deactivated]
    | |   o- alua ............................................... [ALUA Groups: 1]
    | |     o- default_tg_pt_gp ................... [ALUA state: Active/optimized]
    | o- pscsi .............................................. [Storage Objects: 0]
    | o- ramdisk ............................................ [Storage Objects: 0]
    o- iscsi ........................................................ [Targets: 1]
    | o- iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319  [TPGs: 1]
    |   o- tpg1 ........................................... [no-gen-acls, no-auth]
    |     o- acls ...................................................... [ACLs: 0]
    |     o- luns ...................................................... [LUNs: 0]
    |     o- portals ................................................ [Portals: 1]
    |       o- 0.0.0.0:3260 ................................................. [OK]
    o- loopback ..................................................... [Targets: 0]
    o- sbp .......................................................... [Targets: 0]
    o- vhost ........................................................ [Targets: 0]
    o- xen-pvscsi ................................................... [Targets: 0]
    />
IPv6

To enable IPv6 for the portal, delete IPv4 entry first, then create IPv6.

iscsi/iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319/tpg1/portals/ delete 0.0.0.0 3260
iscsi/iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319/tpg1/portals/ create ::0 3260
Lun

We need to attach our backstore, disk01, to the newly created iSCSI entry:

/> iscsi/iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319/tpg1/luns create /backstores/fileio/disk01
Created LUN 0.
/> ls
o- / ....................................................................................................... [...]
  o- backstores ............................................................................................ [...]
  | o- block ................................................................................ [Storage Objects: 0]
  | o- fileio ............................................................................... [Storage Objects: 1]
  | | o- disk01 ................................................. [/tmp/disk01.img (10.0GiB) write-back activated]
  | |   o- alua ................................................................................. [ALUA Groups: 1]
  | |     o- default_tg_pt_gp ..................................................... [ALUA state: Active/optimized]
  | o- pscsi ................................................................................ [Storage Objects: 0]
  | o- ramdisk .............................................................................. [Storage Objects: 0]
  o- iscsi .......................................................................................... [Targets: 1]
  | o- iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319 .................................. [TPGs: 1]
  |   o- tpg1 ............................................................................. [no-gen-acls, no-auth]
  |     o- acls ........................................................................................ [ACLs: 0]
  |     o- luns ........................................................................................ [LUNs: 1]
  |     | o- lun0 ........................................... [fileio/disk01 (/tmp/disk01.img) (default_tg_pt_gp)]
  |     o- portals .................................................................................. [Portals: 1]
  |       o- [::0]:3260 ..................................................................................... [OK]
  o- loopback ....................................................................................... [Targets: 0]
  o- sbp ............................................................................................ [Targets: 0]
  o- vhost .......................................................................................... [Targets: 0]
  o- xen-pvscsi ..................................................................................... [Targets: 0]
/>
Acls

To allow initiator iqn.2005-03.org.open-iscsi:a3beddeaf977 to access our target:

/> iscsi/iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319/tpg1/acls create wwn=iqn.2005-03.org.open-iscsi:a3beddeaf977
Created Node ACL for iqn.2005-03.org.open-iscsi:a3beddeaf977
Created mapped LUN 0.
/> ls
o- / ....................................................................................................... [...]
  o- backstores ............................................................................................ [...]
  | o- block ................................................................................ [Storage Objects: 0]
  | o- fileio ............................................................................... [Storage Objects: 1]
  | | o- disk01 ................................................. [/tmp/disk01.img (10.0GiB) write-back activated]
  | |   o- alua ................................................................................. [ALUA Groups: 1]
  | |     o- default_tg_pt_gp ..................................................... [ALUA state: Active/optimized]
  | o- pscsi ................................................................................ [Storage Objects: 0]
  | o- ramdisk .............................................................................. [Storage Objects: 0]
  o- iscsi .......................................................................................... [Targets: 1]
  | o- iqn.2003-01.org.linux-iscsi.alpine-hp-01.x8664:sn.159f1aa77319 .................................. [TPGs: 1]
  |   o- tpg1 ............................................................................. [no-gen-acls, no-auth]
  |     o- acls ........................................................................................ [ACLs: 1]
  |     | o- iqn.2005-03.org.open-iscsi:a3beddeaf977 ............................................ [Mapped LUNs: 1]
  |     |   o- mapped_lun0 ............................................................. [lun0 fileio/disk01 (rw)]
  |     o- luns ........................................................................................ [LUNs: 1]
  |     | o- lun0 ........................................... [fileio/disk01 (/tmp/disk01.img) (default_tg_pt_gp)]
  |     o- portals .................................................................................. [Portals: 1]
  |       o- [::0]:3260 ..................................................................................... [OK]
  o- loopback ....................................................................................... [Targets: 0]
  o- sbp ............................................................................................ [Targets: 0]
  o- vhost .......................................................................................... [Targets: 0]
  o- xen-pvscsi ..................................................................................... [Targets: 0]
/>

Save Config

Existing targetcli save configuration automatically:

/> exit
Global pref auto_save_on_exit=true
Last 10 configs saved in /etc/target/backup/.
Configuration saved to /etc/target/saveconfig.json

Conclusion

This end our first iSCSI target creation. As a final note, targetcli can be used in command line mode, try:

targetcli ls
John Siu
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