|
# Tested on RHEL 6
# iSCSI target configuration # ------------------------------------------------------------------------------------------ # Required package: scsi-target-utils # Some documentation: /usr/share/doc/scsi-target-utils-X.X.XX/README.iscsi # This recipe is about exporting one storage device (LVM volume, disk partition,...), # a target, using the iSCSI protocol in a way that clients can connect to it remotely # For this example I'm exporting a LVM logical volume like following one: lvcreate -n myscsilv -L 4G myvg # Target creation (iSCSI Qualified Name - IQN - ) tgtadm --lld iscsi --op new --mode target --tid 1 -T <iqn.2014-06.com.example.myserver:myiscsi> # Let's associate a device (our logical volume) to the target we've just created tgtadm --lld iscsi --op new --mode logicalunit --tid <1> --lun <1> -b </dev/myvg/myscsilv> # And authorize initiators to connect to our target tgtadm --lld iscsi --op bind --mode target --tid 1 -I 172.257.1/24 tgtadm --lld iscsi --op bind --mode target --tid 1 -I 172.257.2/24 tgtadm --lld iscsi --op bind --mode target --tid 1 -I 172.257.3/24 # DO NOT FORGET to dump configuration to config. file cp -p /etc/tgt/targets.conf /etc/tgt/targets.conf.orig tgt-admin --dump > /etc/tgt/targets.conf cat targets.conf default-driver iscsi <target iqn.2014-06.com.example.myserver:myiscsi> backing-store /dev/myvg/myscsilv initiator-address 172.257.1/24 initiator-address 172.257.2/24 initiator-address 172.257.3/24 </target> # Finaly, enable and restart tgtd daemon chkconfig tgtd on service tgtd restart # Some of the properties like vendor, SN or scsi ID may be modified like this: vi targets.conf default-driver iscsi <target iqn.2014-06.com.example.myserver:myiscsi> <backing-store /dev/myvg/myscsilv> vendor_id MyVendor scsi_sn 1234567890 scsi_id MyDisc-myscsilv </backing-store> initiator-address 172.257.1/24 initiator-address 172.257.2/24 initiator-address 172.257.3/24 </target> service tgtd restart tgt-admin -s Target 1: iqn.2014-06.com.example.myserver:myiscsi System information: Driver: iscsi State: ready I_T nexus information: LUN information: LUN: 0 Type: controller SCSI ID: IET 00010000 SCSI SN: beaf10 Size: 0 MB, Block size: 1 Online: Yes Removable media: No Readonly: No Backing store type: null Backing store path: None Backing store flags: LUN: 1 Type: disk --> SCSI ID: MyDisc-myscsilv --> SCSI SN: 1234567890 Size: 4295 MB, Block size: 512 Online: Yes Removable media: No Readonly: No Backing store type: rdwr Backing store path: /dev/myvg/myscsilv Backing store flags: Account information: ACL information: 172.257.1/24 172.257.2/24 172.257.3/24 # iSCSI initiator configuration # ------------------------------------------------------------------------------------------ # Required package: iscsi-initiator-utils # We are connecting to a storage device (LVM volume, disk partition,...), a target, being # using exported by a remote server, using the iSCSI protocol # Ensure that iscsi daemon is started and enabled for changes to persist across reboots chkconfig iscsi on service iscsi restart # Discover iSCSI target(s) being shared by remote server iscsiadm --mode discoverydb --type sendtargets --portal <172.257.7.4> --discover 172.257.7.4:3260,1 iqn.2014-06.com.example.myserver:myiscsi # or # iscsiadm -m discovery -t st -p <172.257.7.4> # Login to iSCSI target; take we must be authorized to connect on remote server iscsiadm -m node -T <iqn.2014-06.com.example.myserver:myiscsi> -p <172.257.7.4> -l Logging in to [iface: default, target: iqn.2014-06.com.example.myserver:myiscsi, portal: 172.257.7.4,3260] (multiple) Login to [iface: default, target: iqn.2014-06.com.example.myserver:myiscsi, portal: 172.257.7.4,3260] successful. # Note that this attachment is persistent across reboot, even if we disconnect from iSCSI target # Check dmesg [...] sd 2:0:0:1: [sda] 8388608 512-byte logical blocks: (4.29 GB/4.00 GiB) sd 2:0:0:1: [sda] Write Protect is off sd 2:0:0:1: [sda] Mode Sense: 49 00 00 08 sd 2:0:0:1: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sda: unknown partition table sd 2:0:0:1: [sda] Attached SCSI disk scsi 2:0:0:0: Attached scsi generic sg0 type 12 sd 2:0:0:1: Attached scsi generic sg1 type 0 lvmdiskscan | grep sda /dev/sda [ 4.00 GiB] # Stop using a target iscsiadm -m node -T <iqn.2014-06.com.example.myserver:myiscsi> -p <172.257.7.4> -u # This will not remove the configuration for this target. As long as "node.startup" is set to # "automatic" in /etc/iscsi/iscsid.conf file, this target will be rediscovered next time # iscsi daemon is restarted. This means too that any modification in configuration should be # done before descovering targets. Otherwise, changes will not take effect on already # connected targets. For the target to be effectively removed, run following command: iscsiadm -m node -T <iqn.2014-06.com.example.myserver:myiscsi> -p <172.257.7.4> --op delete |