Iscsi Intiator + Multipath

Install the Packages

yum -y install iscsi-initiator-utils
yum install device-mapper-multipath -y
/etc/init.d/multipathd start
/etc/init.d/iscsid start

chkconfig multipathd on
chkconfig iscsid on

#Discover the target.
iscsiadm -m discovery -t sendtargets -p 192.168.1.100

iscsiadm -m discovery -t sendtargets -p 192.168.0.100

# creating new iscsi interface
iscsiadm -m iface -I iscsi-eth1 -o new

iscsiadm -m iface -I iscsi-eth2 -o new

iscsiadm -m iface -I iscsi-eth1 -o update -n iface.net_ifacename -v eth1

iscsiadm -m iface -I iscsi-eth2 -o update -n iface.net_ifacename -v eth2

#login to all discovered targets
iscsiadm -m node -l
#to Create the multipath config file automatically

#multipath -F
/sbin/mpathconf

#else Create a file /etc/multipath.conf with the following content:

echo "
defaults {
udev_dir /dev
polling_interval 10
path_selector "round-robin 0"
path_grouping_policy multibus
path_checker readsector0
rr_min_io 100
max_fds 8192
rr_weight priorities
failback immediate
no_path_retry fail
user_friendly_names yes
}

" >> /etc/multipath.conf
[root@controller1 ~]# /etc/init.d/multipathd restart
ok
Stopping multipathd daemon: [ OK ]
Starting multipathd daemon: [ OK ]
[root@controller1 ~]# multipath -ll
mpatha (36a4badb00053ae7f0000f49e53d73254) dm-3 DELL,MD3000i
size=250G features='3 queue_if_no_path pg_init_retries 50' hwhandler='1 rdac' wp=rw
|-+- policy='round-robin 0' prio=6 status=active
| |- 4:0:0:2 sdb 8:16 active ready running
| `- 5:0:0:2 sdc 8:32 active ready running
`-+- policy='round-robin 0' prio=1 status=enabled
|- 3:0:0:2 sde 8:64 active ghost running
`- 6:0:0:2 sdd 8:48 active ghost running
[root@controller1 ~]#
#Add Following to /etc/multipath.conf
multipaths {
multipath {
wwid 36a4badb00053ae7f0000f49e53d73254
alias lun0
path_grouping_policy multibus
path_checker readsector0
path_selector "round-robin 0"
failback manual
rr_weight priorities
no_path_retry fail
}
}

[root@controller1 ~]# multipath -ll
Jul 29 07:11:45 | multipath.conf line 20, invalid keyword: path_checker
lun0 (36a4badb00053ae7f0000f49e53d73254) dm-3 DELL,MD3000i
size=250G features='3 queue_if_no_path pg_init_retries 50' hwhandler='1 rdac' wp=rw
|-+- policy='round-robin 0' prio=6 status=active
| |- 4:0:0:2 sdb 8:16 active ready running
| `- 5:0:0:2 sdc 8:32 active ready running
`-+- policy='round-robin 0' prio=1 status=enabled
|- 3:0:0:2 sde 8:64 active ghost running
`- 6:0:0:2 sdd 8:48 active ghost running
[root@controller1 ~]#

#List the All DISK's which will include ISCSI drive
fdisk -l

# Use Mkfs to create the file system and mount it using _netdev option

 

More iscsiadm commands

iscsiadm -m session

iscsiadm -m node -u

targets configuration will be in /var/lib/iscsi