Difference between revisions of "Open-iSCSI"

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(rename section: Tips & Troubleshooting)
(Move advice "daemon has to be running" down into Troubleshooting section, since this should be the case if the user follows instructions and starts the service.)
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== Using the Tools ==
 
== Using the Tools ==
{{ic|iscsid}} has  to be running.
 
  
 
=== Target discovery ===
 
=== Target discovery ===
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At the server (target) you might need to include the client iqn from {{ic|/etc/iscsi/initiatorname.iscsi}} in the acl configuration.
 
At the server (target) you might need to include the client iqn from {{ic|/etc/iscsi/initiatorname.iscsi}} in the acl configuration.
 +
 +
Many of the {{ic|iscsiadm}} operations require that the iSCSI daemon {{ic|iscsid}} is running. To verify that this is the case,
 +
[[systemd#Using units|check the status]] of the {{ic|open-iscsi.service}}.
  
 
== See also ==
 
== See also ==
 
* [[iSCSI Boot]] Booting Arch Linux with / on an iSCSI target.
 
* [[iSCSI Boot]] Booting Arch Linux with / on an iSCSI target.

Revision as of 00:42, 24 August 2014

With Wikipedia:iSCSI you can access storage over an IP-based network.

The exported storage entity is the target and the importing entity is the initiator.

This article describes how to access an iSCSI target with the Open-iSCSI initiator.

Installation

Install the open-iscsi package from the official repositories.

Note: An older initiator, Linux-iSCSI, was merged with Open-iSCSI in April 2005. This should not be confused with linux-iscsi.org, the website for the LIO target.

Start the Service

Start open-iscsi.service using systemd.

Tango-view-refresh-red.pngThis article or section is out of date.Tango-view-refresh-red.png

Reason: The following advice about /etc/conf.d/open-iscsi might be out of date, see discussion page (Discuss in Talk:Open-iSCSI#)

You only have to include the IP of the target as SERVER in /etc/conf.d/open-iscsi at the client.

Using the Tools

Target discovery

# iscsiadm -m discovery -t sendtargets -p <portalip>

Delete obsolete targets

# iscsiadm -m discovery -p <portalip> -o delete

Login to available targets

# iscsiadm -m node -L all

or login to specific target

# iscsiadm -m node --targetname=<targetname> --login

logout:

# iscsiadm -m node -U all

Info

For running session

# iscsiadm -m session -P 3

The last line of the above command will show the name of the attached dev e.g

Attached scsi disk sdd State: running

For the known nodes

# iscsiadm -m node

Online resize of volumes

If the iscsi blockdevice contains a partitiontable, you will not be able to do an online resize. In this case you have to unmount the filesystem and alter the size of the affected partition.

  1. Rescan active nodes in current session
    # iscsiadm -m node -R
  2. If you use multipath, you also have to rescan multipath volume information.
    # multipathd -k"resize map sdx"
  3. Finally resize the filesystem.
    # resize2fs /dev/sdx

Tips & Troubleshooting

You can also check where the attached iSCSI devices are located in the /dev tree with ls -lh /dev/disk/by-path/* .

At the server (target) you might need to include the client iqn from /etc/iscsi/initiatorname.iscsi in the acl configuration.

Many of the iscsiadm operations require that the iSCSI daemon iscsid is running. To verify that this is the case, check the status of the open-iscsi.service.

See also

  • iSCSI Boot Booting Arch Linux with / on an iSCSI target.