[COLUG] iscsi notes

[Travis Sidelinger]

Jim,

Can we get copies of those two scripts you had?


Jim Wildman wrote:
> Here is the contents of the cheet sheet I presented.  I'm going to blend
> these into the presentation document.  I'll also post the scripts I was
> using, once I put my lab back together here at the house.
> 
> -- 
> code is based on open-iscsi
> 
> The machines doing the sharing are called targets and must be RHEL5.1
> (tech
> preview) or 5.2 (supported).
> 
> The machines doing the mounting are called initiators and can be RHEL4.5
> or
> 5.x.  Note that there are significant differences in the command set
> between
> 4.5 and 5.x.  These instructions assume 5.x.
> 
> On the target machines, install scsi-target-utils
> service tgtd restart
> chkconfig tgtd on
> 
> Locate a suitable disk and then do...
> # create the TID (target id) and the iqn (iscsi qualified name)
> # as far as I can tell the name is free form, but there is a 'standard'
> # iqn.<date valid>.tld.domain.something:diskN
> tgtadm --lld iscsi --op new --mode target --tid 2 -T
> iqn.2008-05.private.800lab.x335154:disk2
> 
> # attach a disk partition to 'back it' as a lun
> # can be any block device
> tgtadm --lld iscsi --op new --mode logicalunit --tid 2 --lun 1 -b
> /dev/sdb1
> 
> # 'bind' it, or create an acl to allow a specific ip to access it
> # ALL means unrestricted.  You can also do CHAP authentication
> tgtadm --lld iscsi --op bind --mode target --tid 2 -I 10.100.0.145
> 
> # this assumes you have 2 nics and are going to do multipathing
> tgtadm --lld iscsi --op bind --mode target --tid 2 -I 10.128.164.145
> 
> # printout the result
> tgtadm --mode target --op show
> 
> on the initiator
> yum install iscsi-initiator-utils
> echo "InitiatorAlias=a_name" >> /etc/iscsi/initiatorname.iscsi
> 
> service iscsid restart
> chkconfig iscsid on
> 
> then for each target
> 
> iscsiadm -m discovery -st -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 maintain a persistent store of info in
> /var/lib/iscsi.
> 
> To release a disk, use -u (instead of -l) or -o delete to remove it from
> /var/lib/iscsi
> 
> Once the disks are attached, you can use them for md volumes, lvm, or
> raw partitions.  If you put them in fstab, use the _netdev option so
> they will get mounted AFTER the network starts.  Can't use for system
> files, etc for obvious reasons.
> 
> 
> # as far as I can tell the name is free form, but there is a 'standard'
> tgtadm --lld iscsi --op new --mode target --tid 2 -T
> iqn.2008-05.private.800lab.x335154:disk2
> 
> # attach a disk partition to 'back it' as a lun
> tgtadm --lld iscsi --op new --mode logicalunit --tid 2 --lun 1 -b
> /dev/sdb1
> 
> # 'bind' it, or create an acl to allow a specific ip to access it
> tgtadm --lld iscsi --op bind --mode target --tid 2 -I 10.100.0.145
> tgtadm --lld iscsi --op bind --mode target --tid 2 -I 10.128.164.145
> 
> # printout the result
> tgtadm --mode target --op show
> 
> tgtadm --mode target --op show
> Target 2: iqn.2008-05.private.800lab.x335154:disk2
>     System information:
>         Driver: iscsi
>         Status: running
>     I_T nexus information:
>         I_T nexus: 1
>             Initiator: iqn.1994-05.com.redhat:9c24f350284
>             Connection: 0
>                 IP Address: 10.100.0.145
>         I_T nexus: 2
>             Initiator: iqn.1994-05.com.redhat:9c24f350284
>             Connection: 0
>                 IP Address: 10.128.164.145
>     LUN information:
>         LUN: 0
>             Type: controller
>             SCSI ID: deadbeaf2:0
>             SCSI SN: beaf20
>             Size: 0
>             Backing store: No backing store
>         LUN: 1
>             Type: disk
>             SCSI ID: deadbeaf2:1
>             SCSI SN: beaf21
>             Size: 136G
>             Backing store: /dev/sdb1
>     Account information:
>     ACL information:
>         10.100.0.145
>         10.128.164.145
> 
> on the initiator
> 
> 
> Jim Wildman
> Linux Server Engineering
> 
> 
> 
> 
> ------------------------------------------------------------------------
> Jim Wildman, CISSP, RHCE       jim at rossberry.com http://www.rossberry.com
> "Society in every state is a blessing, but Government, even in its best
> state, is a necessary evil; in its worst state, an intolerable one."
> Thomas Paine
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