{"id":6168,"date":"2016-08-09T19:03:08","date_gmt":"2016-08-09T11:03:08","guid":{"rendered":"http:\/\/rmohan.com\/?p=6168"},"modified":"2016-08-09T19:03:08","modified_gmt":"2016-08-09T11:03:08","slug":"iscsi-configuration-on-rhel-7-centos-7-2","status":"publish","type":"post","link":"https:\/\/mohan.sg\/?p=6168","title":{"rendered":"iSCSI Configuration on RHEL 7 \/ CentOS 7"},"content":{"rendered":"

iSCSI Configuration on RHEL 7 \/ CentOS 7<\/h3>\n
<\/div>\n
\n
Step 1: First you need to create partition<\/p>\n

[root@server1 ~]# fdisk -c \/dev\/sdb<\/p>\n

Press ‘p’ to print partition table<\/p>\n

Press ‘n’ to create a new partition<\/p>\n

Press ‘p’ to create primary partition<\/p>\n

Type Partition Number : 1<\/p>\n

First Sector\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 : PRESS ENTER<\/p>\n

Last Sector\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 : +1G<\/p>\n

Press ‘p’ to print partition tables again<\/p>\n

Press ‘t’ to change partition ID<\/p>\n

Type your partition Number :1<\/p>\n

Type Partition code \u00a0\u00a0\u00a0 : 8e<\/p>\n

Press ‘p’ to print partition tables again<\/p>\n

Press ‘w’ to save and exit
\nStep 2: if required, use partprobe command to update partition table entry into kernel.<\/p>\n

[root@server1 ~]# partprobe \/dev\/sdb<\/p>\n

Step 3: Now create a Logical Volume using \/dev\/sdb1 partition<\/p>\n

[root@server1 ~]# pvcreate \/dev\/sdb1<\/p>\n

[root@server1 ~]# vgcreate iSCSI_vg \/dev\/sdb1<\/p>\n

[root@server1 ~]# lvcreate -n iscsi_lv1 -l 100%FREE iSCSI_vg<\/p>\n

Step 4: First you need to install “targetcli” package<\/p>\n

[root@server1 ~]# yum install targetcli -y<\/p>\n

Step 5: Now run targetcli with no options to enter into interactive mode:<\/p>\n

[root@server1 ~]# targetcli<\/p>\n

\/> ls<\/p>\n

Now Configure the existing \/dev\/iSCSI_vg\/iscsi_lv1 logical volume as a block-type backing store using the name of “server1.disk1”.<\/p>\n

\/> cd backstores\/<\/p>\n

\/backstores> ls<\/p>\n

\/backstores> cd block<\/p>\n

\/backstores\/block> ls<\/p>\n

\/backstores\/block> create server1.disk1 \/dev\/iSCSI_vg\/iscsi_lv1<\/p>\n

\/backstores\/block> ls<\/p>\n

Now Create a unique iSCSI Qualified Name (IQN) for the target.<\/p>\n

\/backstores\/block> cd \/iscsi<\/p>\n

\/iscsi> create iqn.2014-10.com.example.server1:iscsi-1<\/p>\n

Now an ACL for client node (initiator). the initiator will be connecting with it’s initiator name.<\/p>\n

\/iscsi> cd \/iscsi\/iqn.2014-10.com.example.server1:iscsi-1\/tpg1\/acls<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/acls> create iqn.2014-10.com.example.com.server1:server2
\nNow set username and password into ACL to access this LUN<\/p>\n

\/> cd iqn.2014-10.com.example.com.server1:server2<\/p>\n

\/> set auth userid=user1<\/p>\n

\/> set auth password=password<\/p>\n

Now Create a LUN under the target, The LUN should use the previously defined backing storage device named “server1.disk1″<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/acls> cd \/iscsi\/iqn.2014-10.com.example.server1:iscsi-1\/tpg1\/luns<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/luns> create \/backstores\/block\/server1.disk1<\/p>\n

Now Configure a portal for the target to listen on 192.168.0.254<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/luns> cd \/iscsi\/iqn.2014-10.com.example.server1:iscsi-1\/tpg1\/portals<\/p>\n

\/iscsi\/iqn.20…\/tpg1\/portals> create 192.168.0.254<\/p>\n

Now view, verify and save the target server configuration<\/p>\n

\/iscsi\/iqn.20…\/tpg1\/portals> cd \/<\/p>\n

\/> ls<\/p>\n

Now Save this configuration<\/p>\n

\/> saveconfig<\/p>\n

\/> exit<\/p>\n

NOTE-: this configuration will be saved to ” ~]# cat \/etc\/target\/saveconfig.json”<\/p>\n

Step 6: Now Enable and Start target service<\/p>\n

[root@server1 ~]# systemctl enable target.service<\/p>\n

[root@server1 ~]# systemctl restart target.service
\n[root@server1 ~]# systemctl status target.service<\/p>\n

Step 7: Now Configure firewall to allow target service
\n[root@server1 ~]# firewall-cmd –permanent –add-port=3260\/tcp
\n[root@server1 ~]# firewall-cmd –reload<\/p>\n

Accessing iSCSI Storage with CHAP Authentication\u00a0 <\/u><\/p>\n

Step 1: First you need to install iSCSI initiator package<\/p>\n

[root@server2 ~]# yum install iscsi-initiator-utils -y<\/p>\n

Step 2: Now Create a unique iSCSI IQN name for the client initiator. Otherwise you will not able to connect\/login into IQN<\/p>\n

[root@server2 ~]# vim \/etc\/iscsi\/initiatorname.iscsi<\/p>\n

InitiatorName=iqn.2014-10.com.example.server1:server2
\n:wq (save and exit)<\/p>\n

Step 3: Now you need to modify “\/etc\/iscsi\/iscsid.conf” to provide username and password for chap authentication<\/p>\n

[root@server2 ~]# vim \/etc\/iscsi\/iscsid.conf<\/p>\n

# line 54: uncomment<\/p>\n

node.session.auth.authmethod = CHAP<\/p>\n

# line 58,59: uncomment and specify the username and password you set on the iSCSI target server<\/p>\n

node.session.auth.username = user1<\/p>\n

node.session.auth.password = password
\n:wq (save and exit)<\/p>\n

Step 4: Now Enable and start iscsi client service
\n[root@server2 ~]# systemctl restart iscsid.service<\/p>\n

[root@server2 ~]# systemctl enable iscsid.service<\/p>\n

Step 5: Now discover target using the following command:<\/p>\n

[root@server2 ~]# iscsiadm -m discovery -t st -p 192.168.0.254<\/p>\n

Step 6: Confirm status after discovery<\/p>\n

[root@server2 ~]# iscsiadm -m node -o show<\/p>\n

Step 7: Now connect\/login the discovered target into system<\/p>\n

[root@server2 ~]# iscsiadm -m node -T iqn.2014-10.com.example.server1:tgt1 -p 192.168.0.254 -l
\nStep 8: Confirm the established session<\/p>\n

[root@server2 ~]# iscsiadm -m session -o show<\/p>\n

Step 9: Confirm the partitions<\/p>\n

[root@server2 ~]# cat \/proc\/partitions<\/p>\n

Step 10: Create label,\u00a0 create a new primary partition, format it using xfs file system and the mount it on \/mnt directory.<\/p>\n

[root@server2 ~]# parted –script \/dev\/sdb “mklabel msdos”<\/p>\n

[root@server2 ~]# parted –script \/dev\/sdb “mkpart primary 0% 100%”<\/p>\n

[root@server2 ~]# mkfs.xfs -i size=1024 -s size=4096 \/dev\/sdb1<\/p>\n

[root@server2 ~]# mount \/dev\/sdb1 \/mnt<\/p>\n

[root@server2 ~]# df -hT
\nStep 11: Now make it persistent entry to mount at booting
\n[root@server2 ~]# blkid<\/p>\n

Now Copy the UUID of \/deb\/sdb1 and paste it into \/etc\/fstab as following:<\/p>\n

[root@server2 ~]# vim \/etc\/fstab<\/p>\n

UUID=”be41aa12-1e30-4678-8c19-da3506df1d84″ \/mnt\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xfs\u00a0\u00a0\u00a0\u00a0 _netdev \u00a0\u00a0\u00a0 0 0
\n:wq (save and exit)<\/p>\n

[root@server2 ~]# umount \/mnt\/<\/p>\n

[root@server2 ~]# mount -a<\/p>\n

[root@server2 ~]# df -h Step 12: Now unmount the iSCSI Storage<\/p>\n

[root@server2 ~]# cd<\/p>\n

[root@server2 ~]# umount \/mnt\/<\/p>\n

[root@server2 ~]# vim \/etc\/fstab<\/p>\n

Remove the following entry form this file<\/p>\n

UUID=”be41aa12-1e30-4678-8c19-da3506df1d84″ \/mnt\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xfs\u00a0\u00a0\u00a0\u00a0 _netdev\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 0
\n:wq (save and exit)<\/p>\n

To Disconnect iSCSI storage<\/p>\n

[root@server2 ~]# iscsiadm -m node -T iqn.2014-10.com.example.server1:tgt1 -p 192.168.0.254 -u<\/p>\n

To delete cache as well<\/p>\n

[root@server2 ~]# iscsiadm -m node -T iqn.2014-10.com.example.server1:tgt1 -p 192.168.0.254 -o delete<\/div>\n

Now if you want to connect it again, you need to discover it again.<\/p>\n

Configuring iSCSI Targets without CHAP Authentication <\/u><\/p>\n

Step 1: First you need to create partition<\/p>\n

[root@server1 ~]# fdisk -c \/dev\/sdc<\/p>\n

Press ‘p’ to print partition table<\/p>\n

Press ‘n’ to create a new partition<\/p>\n

Press ‘p’ to create primary partition<\/p>\n

Type Partition Number : 1<\/p>\n

First Sector\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 : PRESS ENTER<\/p>\n

Last Sector\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 : +1G<\/p>\n

Press ‘p’ to print partition tables again<\/p>\n

Press ‘t’ to change partition ID<\/p>\n

Type your partition Number :1<\/p>\n

Type Partition code \u00a0\u00a0\u00a0 : 8e<\/p>\n

Press ‘p’ to print partition tables again<\/p>\n

Press ‘w’ to save and exit<\/p>\n

Step 2: if required, use partprobe command to update partition table entry into kernel.<\/p>\n

[root@server1 ~]# partprobe \/dev\/sdc<\/p>\n

Step 3: Now create a Logical Volume using \/dev\/sdc1 partition
\n[root@server1 ~]# pvcreate \/dev\/sdc1<\/p>\n

[root@server1 ~]# vgcreate iSCSI_vg2 \/dev\/sdc1<\/p>\n

[root@server1 ~]# lvcreate -n iscsi_lv2 -l 100%FREE iSCSI_vg2<\/p>\n

Step 4: First you need to install “targetcli” package<\/p>\n

[root@server1 ~]# yum install targetcli -y<\/p>\n

Step 5: Now run targetcli with no options to enter into interactive mode:<\/p>\n

[root@server1 ~]# targetcli<\/p>\n

\/> ls<\/p>\n

Now Configure the existing \/dev\/iSCSI_vg2\/iscsi_lv2 logical volume as a block-type backing store using the name of “server1.disk2”.<\/p>\n

\/> cd backstores\/<\/p>\n

\/backstores> ls<\/p>\n

\/backstores> cd block<\/p>\n

\/backstores\/block> ls<\/p>\n

\/backstores\/block> create server1.disk2 \/dev\/iSCSI_vg2\/iscsi_lv2<\/p>\n

\/backstores\/block> ls<\/p>\n

Now Create a unique iSCSI Qualified Name (IQN) for the target.<\/p>\n

\/backstores\/block> cd \/iscsi<\/p>\n

\/iscsi> create iqn.2014-10.com.example.server1:iscsi-2<\/p>\n

Now an ACL for client node (initiator). the initiator will be connecting with it’s initiator name.<\/p>\n

\/iscsi> cd \/iscsi\/iqn.2014-10.com.example.server1:iscsi-2\/tpg1\/acls<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/acls> create iqn.2014-10.com.example.com.server1:tgt1<\/p>\n

By default authentication is enabled. To disable it:<\/p>\n

\/> cd \/iscsi\/iqn.2014-10.com.example.server1:iscsi-2\/tgp1\/<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1> set attribute authentication=0<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1> set attribute generate_node_acls=1<\/p>\n

Now Create a LUN under the target, The LUN should use the previously defined backing storage device named “server1.disk2″<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/acls> cd \/iscsi\/iqn.2014-10.com.example.server1:iscsi-2\/tpg1\/luns<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/luns> create \/backstores\/block\/server1.disk2<\/p>\n

Now Configure a portal for the target to listen on 192.168.0.254<\/p>\n

\/iscsi\/iqn.20…i-1\/tpg1\/luns> cd \/iscsi\/iqn.2014-10.com.example.server1:iscsi-2\/tpg1\/portals<\/p>\n

\/iscsi\/iqn.20…\/tpg1\/portals> create 192.168.0.254<\/p>\n

Now view, verify and save the target server configuration<\/p>\n

\/iscsi\/iqn.20…\/tpg1\/portals> cd \/<\/p>\n

\/> ls<\/p>\n

Now Save this configuration<\/p>\n

\/> saveconfig<\/p>\n

\/> exit<\/p>\n

NOTE-: this configuration will be saved to ” ~]# cat \/etc\/target\/saveconfig.json”<\/p>\n

Step 6: Now Enable and Start target service<\/p>\n

[root@server1 ~]# systemctl enable target.service<\/p>\n

[root@server1 ~]# systemctl restart target.service
\n[root@server1 ~]# systemctl status target.service<\/p>\n

Step 7: Now Configure firewall to allow target service<\/p>\n

[root@server1 ~]# firewall-cmd –permanent –add-port=3260\/tcp
\n[root@server1 ~]# firewall-cmd –reload<\/p>\n

Accessing iSCSI Storage without CHAP Authentication\u00a0<\/u> <\/u><\/p>\n

Step 1: First you need to install iSCSI initiator package
\n[root@server2 ~]# yum install iscsi-initiator-utils -y<\/p>\n

Step 2: Now Create a unique iSCSI IQN name for the client initiator. Otherwise you will not able to connect\/login into IQN<\/p>\n

[root@server2 ~]# vim \/etc\/iscsi\/initiatorname.iscsi<\/p>\n

InitiatorName=iqn.2014-10.com.example.server1:tgt1<\/p>\n

:wq (save and exit)<\/p>\n

Step 3: Now Enable and start iscsi client service<\/p>\n

[root@server2 ~]# systemctl restart iscsid.service<\/p>\n

[root@server2 ~]# systemctl enable iscsid.service<\/p>\n

Step 4: Now discover target using the following command:
\n[root@server2 ~]# iscsiadm -m discovery -t st -p 192.168.0.254<\/p>\n

Step 5: Now you need to connect iscsi storage into system<\/p>\n

[root@server2 ~]# iscsiadm -m node -T iqn.2014-10.com.example.server1:iscsi-2 -p 192.168.0.254 -l<\/p>\n

[root@server2 ~]# fdisk -l<\/p>\n

Step 6: Create label,\u00a0 create a new primary partition, format it using xfs file system and the mount it on \/iscsi2 directory.<\/p>\n

[root@server2 ~]# parted –script \/dev\/sdb “mklabel msdos”<\/p>\n

[root@server2 ~]# parted –script \/dev\/sdb “mkpart primary 0% 100%”<\/p>\n

[root@server2 ~]# mkfs.xfs -i size=1024 -s size=4096 \/dev\/sdb1<\/p>\n

[root@server2 ~]# mount \/dev\/sdb1 \/iscsi2<\/p>\n

[root@server2 ~]# df -hT<\/p>\n

Step 7: Now make it persistent entry to mount at booting<\/p>\n

[root@server2 ~]# blkid<\/p>\n

Now Copy the UUID of \/deb\/sdc1 and paste it into \/etc\/fstab as following:<\/p>\n

[root@server2 ~]# vim \/etc\/fstab<\/p>\n

UUID=”be41aa12-1e30-4678-8c19-da3506df1d84″ \/iscsi2\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xfs\u00a0\u00a0\u00a0\u00a0 _netdev \u00a0\u00a0\u00a0 0 0<\/p>\n

:wq (save and exit)<\/p>\n

[root@server2 ~]# umount \/mnt\/<\/p>\n

[root@server2 ~]# mount -a<\/p>\n

[root@server2 ~]# df -h<\/p>\n

Step 8: Now unmount the iSCSI Storage<\/p>\n

[root@server2 ~]# cd<\/p>\n

[root@server2 ~]# umount \/iscsi2<\/p>\n

[root@server2 ~]# vim \/etc\/fstab<\/p>\n

Remove the following entry form this file<\/p>\n

UUID=”be41aa12-1e30-4678-8c19-da3506df1d84″ \/mnt\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xfs\u00a0\u00a0\u00a0\u00a0 _netdev\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 0<\/p>\n

:wq (save and exit)<\/p>\n

To Disconnect iSCSI storage<\/p>\n

root@server2 ~]# iscsiadm -m node -T iqn.2014-10.com.example.server1:iscsi-2 -p 192.168.0.254 -u<\/p>\n

To delete cache as well<\/p>\n

[root@server2 ~]# iscsiadm -m node -T iqn.2014-10.com.example.server1:iscsi-2 -p 192.168.0.254 -o delete<\/p>\n

Now if you want to connect it again, you need to discover it again.
\nNOTE-: iSCSI store caching in\u00a0 \/var\/lib\/iscsi\/ directory sometimes when we try to add another iscsi targets, system takes some information
\nfrom cache. so you have two option to address it.<\/p>\n

1. reboot your system<\/p>\n

2. remove iscsi cache<\/p>\n

To remove nodes cache
\n[root@server2 ~]# rm -rf \/var\/lib\/iscsi\/nodes\/*<\/p>\n

To remove send_targets cache<\/p>\n

[root@server2 ~]# rm -rf \/var\/lib\/iscsi\/send_targets\/*<\/p><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

iSCSI Configuration on RHEL 7 \/ CentOS 7 Step 1: First you need to create partition<\/p>\n

[root@server1 ~]# fdisk -c \/dev\/sdb<\/p>\n

Press ‘p’ to print partition table<\/p>\n

Press ‘n’ to create a new partition<\/p>\n

Press ‘p’ to create primary partition<\/p>\n

Type Partition Number : 1<\/p>\n

First Sector : PRESS ENTER<\/p>\n

Last Sector : +1G<\/p>\n

Press […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[73],"tags":[],"_links":{"self":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/6168"}],"collection":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6168"}],"version-history":[{"count":1,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/6168\/revisions"}],"predecessor-version":[{"id":6169,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/6168\/revisions\/6169"}],"wp:attachment":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6168"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6168"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6168"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}