[CentOS] iscsi and the last mile...

Thu Aug 21 03:17:46 UTC 2008
Jim Wildman <jim at rossberry.com>

Scott R. Ehrlich wrote:
> On Wed, 20 Aug 2008, Jim Wildman wrote:
>> Scott R. Ehrlich wrote:
>>> I have a new Dell PowerEdge 2950 running CentOS 5.0 out-of-box and a 
>>> Dell MD3000i.   I am new to iscsi and, with google and included 
>>> documentation, am having a heck of a time trying to get the RAID 
>>> volumes I have created on the 3000i to be seen by the OS as usuable 
>>> drives.    I have printed out SMcli and iscsiadm documentation.
>>> I have asked on the linux-poweredge at dell.com site, too.
>> Definitely suggest you update to the latest CentOS if you are in fact 
>> on a 5.0 box.  I'll dig out some notes and post them later tonight.
> I'd greatly appreciate it.  I'd also be curious how the version of 
> Linux might impact my ability to access the partitions vs using iscsi 
> commands to do so...
> Scott
 From my notes on using iscsi CentOS to CentOS (Don't have any other 
iscsi devices)

on the initiator
yum install iscsi-initiator-utils
echo "InitiatorAlias=some_meaningful_name" >> /etc/iscsi/initiatorname.iscsi

service iscsid restart
chkconfig iscsid on

then for each target (assuming no chap auth, etc)

iscsiadm -m discovery -p <ip of target>

grab the iqn and 'login' with it

iscsiadm -m node -T <iqn> -p <ip of target> -l

fdisk -l should show the new disk

if multipathd is running, and you repeat the -l command with the same
iqn, but the other ip, then mulitpathd should join them up according to
the rules you have setup (/etc/multipath.conf)

The iscsiadm commands as implemented by RH, maintain a persistent store
of info in /var/lib/iscsi, not in /etc/iscsi.

To release a disk, use -u (instead of -l) or -o delete to remove it from

Jim Wildman, CISSP, RHCE       jim at rossberry.com http://www.rossberry.com
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