I had some problems using the debian open-iscsi package to connect to the md3000i on debian etch; both package versions 2.0.869.2-2 and 2.0.730-1etch1. A couple folks on the open-iscsi list pointed out there were problems with the kernel modules, so I compiled those from the open-iscsi source and diverted the debian modules. Details are here on the list.

Most open-iscsi documentation is in the README.

# iscsiadm -m discovery –type sendtargets –portal 10.0.9.10 -P 1
Target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a
Portal: 10.0.9.12:3260,2
Iface Name: default
Portal: 10.0.9.11:3260,1
Iface Name: default
Portal: 10.0.9.10:3260,1
Iface Name: default
Portal: 10.0.9.13:3260,2
Iface Name: default

The MD3000i has two controllers each with one out of band management port and two iscsi ports which can be seen above.  When logging in, it grabs all the disks mapped as seperate devices. I removed the ‘access’ mapping which is that odd 16/20mb partition. Notes about that are deep in here, and I remember Dell telling me it wasn’t really needed on the Windows server either.

# iscsiadm -m node -l
Logging in to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.12,3260]
Logging in to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.13,3260]
Logging in to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.10,3260]
Logging in to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.11,3260]
Login to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.12,3260]: successful
Login to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.13,3260]: successful
Login to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.10,3260]: successful
Login to [iface: default, target: iqn.1984-05.com.dell:powervault.6001c23000d59fc6000000004754447a, portal: 10.0.9.11,3260]: successful

It logs in to each portal interface. I guess you use dm_multipath to hook them all back together, but I haven’t gotten that far.

 # cat /proc/partitions
major minor  #blocks  name

8     0    3145728 sda
8     1    2947896 sda1
8     2          1 sda2
8     5     192748 sda5
8    16  584888320 sdb
8    17  584886456 sdb1
8    32  584888320 sdc
8    33  584886456 sdc1
8    48  584888320 sdd
8    64  584888320 sde

sd[b-e] are the same disk, through each portal. You’ll notice it only shows a partition on two of the four, that’s the controller that is the “preferred path”. If we switch the preferred controller, the disks that are usable switch to the other pair. Again, I’m assumimg dm_multipath will clean that up.