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We have an IBM P505 AIX box, with two internal disks and a defined iSCSI volume.

The iSCSI volume is defined in it's own volume group, and is connected to an IBM iSCSI DS3300 disk array via the secondary onboard ethernet port (ie, we're not using a dedicated HBA, we're using the second onboard ethernet port for iSCSI exclusively.)

When we reboot the AIX box, the iSCSI volume doesn't get mounted (which is fine; I've figured out that it fails to mount because AIX tries mounting it's volumes before starting the networking stack.)

The problem is, after the server has booted it fails to redetect the iSCSI target as a physical disk. This means the volume group (iscsivg) can't go online. if I run cfgmgr -v to redetect the iscsi volume it successfully detects the iscsi target volume and creates a physical volume reference, but allocates it a different volume ID to what was defined before.

eg -

  • rootvg contains hdisk 0 and 1
  • iscsivg was originally defined with hdisk2 as the physical iSCSI volume.

after reboot and running cfgmgr -v, AIX detects physical volumes hdisk0, hdisk11 and hdisk3.

  • As there's no hdisk2, I can't varyon the iscsivg volume group.
  • I can't seem any existing hdisk2 definition in the ODM.

I can't easily add or change the definition of the physcial disk in the iscsivg volume group as it won't "varyon". Exporting the volume group deletes it completely, recreating the volume group by "importing" it from the reallocated disk makes it available again, but surely there's a better way?

Can I force a specific hdisk drive designation for an iscsi target?

How do you bring online iSCSI volumes after a reboot?

I assume this "just works" with a dedicated HBA instead of a generic ethernet adapter?

By the way, the iSCSI volume works fine once it's mounted; we only have problems getting it working - and only with AIX. The iSCSI array works fine with our Linux and Windows servers; ie the volumes get detected and remounted after boot time without any problems, using generic ethernet adapters.

Here's some of the config from the AIX box:

defined disks / devices:

 # lsdev

hdisk0     Available 06-08-01-5,0  16 Bit LVD SCSI Disk Drive
hdisk1     Available 06-08-01-8,0  16 Bit LVD SCSI Disk Drive
hdisk3     Available               Other iSCSI Disk Drive
iscsi0     Available               iSCSI Protocol Device
scsi0      Available 06-08-00      PCI-X Dual Channel Ultra320 SCSI Adapter bus
scsi1      Available 06-08-01      PCI-X Dual Channel Ultra320 SCSI Adapter bus
ses0       Available 06-08-01-15,0 SCSI Enclosure Services Device
sisscsia0  Available 06-08         PCI-X Dual Channel Ultra320 SCSI Adapter

iscsi target definition in /etc/iscsi/targets:

# IBM DS3300 disk array
# port 1 on second controller  3260

physical volumes (after reimporting the volume group)

# lspv
hdisk0          0003b08a0d4936b6                    rootvg          active
hdisk1          0003b08aaa5cb366                    rootvg          active
hdisk3          0003b08a032d04bb                    iscsivg         active
share|improve this question
up vote 1 down vote accepted

You will need to ensure that you have configured the discovery policy for your iSCSI devices correctly.

Check out the following link which will give you the information your require.

Good Luck

Mike Scheerer Senior Technical Consultant Keystone Computer Group

share|improve this answer
Might help if I give you the link...… Sorry... – Mike Scheerer Apr 22 '10 at 10:02

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