Linux iSCSI

1. apt-get install open-iscsi
     or oracle linux
   yum install iscsi-initiator-utils.x86_64
    
   
2. Add the correct IP and network device number entry to /etc/network/interfaces for UBUNTU servers.

   	## iSCSI
   	auto eth.<network device number>
   	iface eth.<network device number> inet static
   	address 10.1.1.<###>
   	netmask 255.255.255.0
   	broadcast 10.1.1.255

3. vi /etc/iscsi/iscsid.conf
   • change node.startup from manual to automatic
   
   
4. Restart the initiator & the daemon :
   /etc/init.d/open-iscsi restart
     or RHEL 5 & 6
   /etc/init.d/iscsid restart; /etc/init.d/iscsi restart
     or RHEL7
   /usr/bin/systemctl restart iscsid
   /usr/bin/systemctl restart iscsi :: Because the iscsi disk can't be found yet, this will run a long time.
   

   RHEL6 will require this to start iSCSI:   service iscsid force-start
   ...and it still might not start.
   Run /etc/init.d/iscsid restart; /etc/init.d/iscsi restart
   The supplied /etc/iscsi/iscsi.conf must be used.
   I have a doctored file that includes the oracle parms at:
   http://curubuntu.cc.binghamton.edu/iscsid.config.oracle .
   Replace and try this one it could save time later.

5. /sbin/iscsiadm -m discovery -d 5 -t st -p 10.1.1.1:3260 # -d 5 is debug/verbose lines
   -- COMPLELLENT --
   /sbin/iscsiadm -m discovery -d 5 -t st -p 10.1.2.14:3260 # -d 5 is debug/verbose lines
   /sbin/iscsiadm -m discovery -d 5 -t st -p 10.1.2.15:3260 # -d 5 is debug/verbose lines
   ( A target name or names will be returned. Note It for STEP 5:   ...   iqn.*........*)
    
   If this fails or has an errant return try this to remove the current discovery records:
   /sbin/iscsiadm -m discovery -t sendtargets -p 10.1.1.1:3260 -o delete
   For complete purge :   cd /var/lib/iscsi/nodes; rm -rf * ... for some recovery add /bin/tar -cvf nodes.tar nodes/* inbetween those two commands.
    
   To refresh an existing system to see the connected LUNs.....
   /sbin/iscsiadm -m session -R
    
   NOTE: To get the login/out to work you must have the network device identified.
   For most of the systems this will do that:   iscsiadm -m iface -I eth1 --op=new
   NOTE: if a volume group is not activate it with this command: vgchange -a y
   A non disruptive method to disconnect or connect a discovered LUN:

   # /sbin/iscsiadm -m node -T iqn name --logout
   Logging out of session [sid: 1, target: iqn name, portal: 10.1.1.1,3260]
   Logout of [sid: 1, target: iqn name, portal: 10.1.1.1,3260] successful.
   # /sbin/iscsiadm -m session -R
   iscsiadm: No session found.
   
   # /sbin/iscsiadm -m node --interface=eth<device number> -T < iqn name > --login
   Logging in to [iface: eth<device number>, target: < iqn name >, portal: 10.1.1.1,3260] (multiple)
   Login to [iface: eth<device number>, target: < iqn name >, portal: 10.1.1.1,3260] successful.
   # /sbin/iscsiadm -m session -R
   Rescanning session [sid: 2, target: i< iqn name >, portal: 10.1.1.1,3260]

    -- login to all
   iscsiadm -m node -l

6. /sbin/iscsiadm --mode node --targetname     < iqn name >     -p 10.1.1.1:3260
   -- COMPLELLENT --
   /sbin/iscsiadm --mode node --targetname     < iqn name >     -p 10.1.2.14:3260
   /sbin/iscsiadm --mode node --targetname     < iqn name >     -p 10.1.2.15:3260
    
   Regarding the Compellent for example given what the discover returns for each pair.
   /sbin/iscsiadm --mode node --targetname iqn.2002-03.com.compellent:5000d31001266824 -p 10.1.2.15:3260
   /sbin/iscsiadm --mode node --targetname iqn.2002-03.com.compellent:5000d31001266826 -p 10.1.2.15:3260
   /sbin/iscsiadm --mode node --targetname iqn.2002-03.com.compellent:5000d31001266823 -p 10.1.2.14:3260
   /sbin/iscsiadm --mode node --targetname iqn.2002-03.com.compellent:5000d31001266825 -p 10.1.2.14:3260
    
   
7. cd /var/lib/iscsi/nodes/<IQN returned in step 4>-<hostname>/<ip>,<port>,1/
   UBUNTU: cd /etc/iscsi/nodes
    
   
8. vi default
   This can be useful: find . -name default -print | xargs vi
   • change node.startup from manual to automatic
         node.conn[0].startup = automatic
   
   
9. Restart the initiator: & the daemon
   • /etc/init.d/open-iscsi restart
       RHEL5 &am[ 6
     
   • /etc/init.d/iscsid restart; /etc/init.d/iscsi restart
       RHEL7
     
   • /usr/bin/systemctl restart iscsid
     /usr/bin/systemctl restart iscsi
    
   
10. fdisk -l # you should now see the new disk...create your filesystem.
     
    
11. Do so with Logical Volume Manager: lvm
     
    

The LVM GUI is not longer available but the new scheme is actually a bit simpler.

1. fdisk -l should return the device name that is in /dev generally it will be sdb.
   This example will use that expectation. Also VG will be VolGroup01. Use any VG you wish.
    
   
2. Create the Physical Volume: /sbin/pvcreate /dev/sdb
   Check with pvscan or pvdisplay
    
   
3. Create the Volume Group: /sbin/vgcreate VolGroup01 /dev/sdb
   Check with vgscan or vgdisplay
    
   
4. Create the Logical Volume(s): /usr/local/bin/mk-lvcreate.sh

   usage: /usr/local/bin/mk-lvcreate.sh <volgroupname> <size> <logicalvolumename>
                                                        size in gigabyte no G
           For example:  /usr/local/bin/mk-lvcreate.sh VolGroup01 350 u01

   Check with lvscan or lvdisplay
    
   
5. Create the File Systems: /usr/local/bin/mk-mkfs.sh

   usage: /usr/local/bin/mk-mkfs.sh <volgroupname>
          This will create commands to make the filesystems for the LV's defined above ...
          AND if they look good:  /usr/local/bin/mk-mkfs.sh <volgroupname> > /tmp/mkfs.sh ; sh /tmp/mkfs.sh

6. Create the Mount Points: /usr/local/bin/mk-mp.sh

   usage: /usr/local/bin/mk-mp.sh <volgroupname>
          This will echo the commands to creating mount points.
          AND if they look good:  /usr/local/bin/mk-mp.sh <volgroupname> > /tmp/mkmp.sh ; sh /tmp/mkmp.sh

   Check with ls -ltr /
7. Create the entries for /etc/fstab: /usr/local/bin/mk-fstab-entry.sh

   usage: /usr/local/bin/mk-fstab-entry.sh <volgroupname>
      AND if they look good. cp -p /etc/fstab /etc/0.fstab; /usr/local/bin/mk-mp.sh <volgroupname> >> /etc/fstab

   Check two ways: cat /etc/fstab
umount -a ; ls -ltr ; mount -a ; ls -ltr

1. cd /etc/iscsi
2. vi initiatorname.iscsi
3. Change the InitiatorName from iqn.1988-12.com.oracle:c4d4f1486d52
   to some string unique to the server like ... iqn.1988-12.com.oracle-<FQDN>
   for example: iqn.1988-12.com.oracle-adirdb.cc.binghamton.edu
4. Email the new InitatorName and theHostname to Gary.
5. When he indicates he has changed his settings ... reboot
6. Confirm the volume and partitions are still what you created.

1. cuddletech.com  
   
2. howtoforge/iscsi_on_linu  
   
3. linux-iscsi.sourceforge