This is the second article of the serie about iSCSI. In this one, you will
learn how to connect to an iSCSI target using OpenBSD base daemon iscsid.
The configuration file of iscsid doesn’t exist by default, its location is
/etc/iscsi.conf. It can be easily written using the following:
target1="100.64.2.3"
myaddress="100.64.2.2"
target "disk1" {
initiatoraddr $myaddress
targetaddr $target1
targetname "iqn.1994-04.org.netbsd.iscsi-target:target0"
}
While most lines are really obvious, it is mandatory to have the line
initiatoraddr, many thanks to cwen@ for pointing this out when I was stuck on
it.
The targetname value will depend of the iSCSI target server. If you use
netbsd-iscsi-target, then you only need to care about the last part, aka
target0 and replace it by the name of your target (which is target0 for the
default one).
Then we can enable the daemon and start it:
# rcctl enable iscsid
# rcctl start iscsid
In your dmesg, you should see a line like:
sd4 at scsibus0 targ 1 lun 0: <NetBSD, NetBSD iSCSI, 0> SCSI3 0/direct fixed t10.NetBSD_0x5c6cf1b69fc3b38a
If you use netbsd-iscsi-target, the whole line should be identic except for the
sd4 part which can change, depending of your hardware.
If you don’t see it, you may need to reload iscsid configuration file with
iscsictl reload.
Warning: iSCSI is a bit of pain to debug, if it doesn’t work, double check the
IPs in /etc/iscsi.conf, check your PF rules on the initiator and the
target. You should be at least able to telnet into the target IP port 3260.
Once you found your new sd device, you can format it and mount it as a regular
disk device:
# newfs /dev/rsd4c
# mount /dev/sd4c /mnt
iSCSI is far mor efficient and faster than NFS but it has a total different
purpose. I’m using it on my powerpc machines to build packages on it. This
reduce their old IDE disks usage while giving better response time and
equivalent speed.