Installing CentOS to an iSCSI target

The CentOS installation process is somewhat fragile, and the built-in support for iSCSI installation does not function properly except in very limited circumstances. However, it is possible to work around this limitation and install to an iSCSI target.

Start a CentOS installation in the usual way, and proceed up to the point of the partitioning screen:

Click on Advanced storage configuration, and add an iSCSI target. For the target IP address, enter 127.0.0.1:

You will see the message “Initializing iSCSI initiator” appear for several seconds, then the display will return to the partitioning screen.

Press Ctrl-Alt-F2. This should take you to a root shell prompt. Connect to the iSCSI target to be used for installation:

  sh-3.2# iscsiadm -m discovery -t sendtargets -p my.target.dns.name:3260

where my.target.dns.name is the DNS name (or IP address) of your iSCSI target. You will see a list of available target IQNs. Log in to the installation target:

  sh-3.2# iscsiadm -m node -T iqn.2007-08.name.dns.target.my:iscsiboot -l

where iqn.2007-08.name.dns.target.my:iscsiboot is the IQN of the target that you want to install to.

You are now logged in to the installation iSCSI target.

Press Ctrl-Alt-F6 to return to the graphical installation process, and click on Next to proceed to the disk selection screen:

You must tick the “Review and modify partitioning layout” box before proceeding to the disk partitioning screen:

Select and delete the swap partition. This is required for two reasons: firstly, swap over iSCSI (or over any network device) is generally a bad idea; secondly, doing so works around a bug in the CentOS installer which would otherwise result in the partition table never being written to disk.

Make a note of the iSCSI target IQN that you installed to (iqn.2007-08.name.dns.target.my:iscsiboot in the above example). You are now ready to

• Boot from your iSCSI target image