Centos 4 and the Linux iScsi Target

I wanted to do some tests with the Microsoft iScsi initiator and the Linux iScsi target, but first I had to install and configure the target. I had Centos 4.4 (a RHEL4 Linux clone) setup in VmWare, so i thought that using that would be the easy way to do the test.

I had read in PcPro magazine, last year, issue 137 (March 2006) page 197, that the Linux iScsi target would compile & install on Centos-4, but they did not say exactly which version they used.

Ok, so I download the latest version "iscsitarget-0.4.14.tar.gz".

I knew there was a potential problem, as the README file said it needed kernel version of 2.6.14 or newer, and the CONFIG_CRYPTO_CRC32C option had to be enabled. Centos 4.4 uses kernel 2.6.9, but with many additional patches from latter kernels, and the PCpro people said it would be ok.

Ok, so lets try it:

# cat /etc/redhat-release
CentOS release 4.4 (Final)
# uname -a
Linux localhost.localdomain 2.6.9-42.0.3.EL #1 Fri Oct 6 05:59:54 CDT 2006 i686 i686 i386 GNU/Linux
# cat /usr/src/kernels/2.6.9-42.0.3.EL-i686/crypto/Kconfig | grep -A 6 CRC
config CRYPTO_CRC32C
       tristate "CRC32c CRC algorithm"
       depends on CRYPTO
       select LIBCRC32C
       help
         Castagnoli, et al Cyclic Redundancy-Check Algorithm.  Used
         by iSCSI for header and data digests and by others.
         See Castagnoli93.  This implementation uses lib/libcrc32c.
         Module will be crc32c.

# cd /home
# tar xfz iscsitarget-0.4.14.tar.gz
# chown -R root:root iscsitarget-0.4.14
# ll
drwxr-xr-x  7 root root  4096 Oct 19 10:48 iscsitarget-0.4.14
-rw-r--r--  1 root root 92608 Mar 14  2006 iscsitarget-0.4.14.tar.gz
# cd iscsitarget-0.4.14
# export KERNELSRC=/usr/src/kernels/2.6.9-42.0.3.EL-i686/
# make
make -C usr
make[1]: Entering directory `/home/iscsitarget-0.4.14/usr'
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o ietd.o ietd.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o iscsid.o iscsid.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o conn.o conn.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o session.o session.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o target.o target.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o message.o message.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o ctldev.o ctldev.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o log.o log.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o chap.o chap.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o event.o event.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o param.o param.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o plain.o plain.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o isns.o isns.c
cc ietd.o iscsid.o conn.o session.o target.o message.o ctldev.o log.o chap.o event.o param.o plain.o isns.o -o ietd -lcrypto
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o ietadm.o ietadm.c
cc ietadm.o param.o -o ietadm
make[1]: Leaving directory `/home/iscsitarget-0.4.14/usr'
make -C /lib/modules/2.6.9-42.0.3.EL/build SUBDIRS=/home/iscsitarget-0.4.14/kernel modules
make[1]: Entering directory `/usr/src/kernels/2.6.9-42.0.3.EL-i686'
 CC [M]  /home/iscsitarget-0.4.14/kernel/tio.o
 CC [M]  /home/iscsitarget-0.4.14/kernel/iscsi.o
 CC [M]  /home/iscsitarget-0.4.14/kernel/nthread.o
 CC [M]  /home/iscsitarget-0.4.14/kernel/wthread.o
 CC [M]  /home/iscsitarget-0.4.14/kernel/config.o
/home/iscsitarget-0.4.14/kernel/config.c:312: error: unknown field `unlocked_ioctl' specified in initializer
/home/iscsitarget-0.4.14/kernel/config.c:312: warning: initialization from incompatible pointer type
/home/iscsitarget-0.4.14/kernel/config.c:313: error: unknown field `compat_ioctl' specified in initializer
/home/iscsitarget-0.4.14/kernel/config.c:313: warning: initialization from incompatible pointer type
make[2]: *** [/home/iscsitarget-0.4.14/kernel/config.o] Error 1
make[1]: *** [_module_/home/iscsitarget-0.4.14/kernel] Error 2
make[1]: Leaving directory `/usr/src/kernels/2.6.9-42.0.3.EL-i686'
make: *** [mods] Error 2

# cat /home/iscsitarget-0.4.14/kernel/config.c | grep -n ioctl
219:static long ioctl(struct file *file, unsigned int cmd, unsigned long arg)
312:    .unlocked_ioctl = ioctl,
313:    .compat_ioctl   = ioctl,

Oops! It failed to compile.
Ok, let's google around and see who else has this problem...

It seems other people are getting the same sort of problem with the target versions 4.13 and 4.12 and the older Centos kernel 2.6.9-22.EL

I found this link, where you can download a patch for the target version 0.4.12, which should allow it to compile on kernel 2.6.9, but I did not try it, as it's a "quick hack - Use at your own risk". Maybe someone else can try this patch and give a report.

Ok, so should I dump Centos-4 for now and install Fedora 6, which has an up-to-date kernel. Or should I try and work out which version of the target it was that the Pcpro guy's were using? Ok, I choose the latter.

I went back and downloaded the older versions of the target. And to cut a long story short, I discovered that this version "iscsitarget-0.4.5.tar.gz" will compile on Centos-4. (If you look at the README for that version of the target, it says it is happy with kernel 2.6.10)
Here is the proof that it compiles:

# tar xfz iscsitarget-0.4.5.tar.gz
# chown -R root:root iscsitarget-0.4.5
# cd iscsitarget-0.4.5
# make
make -C usr
make[1]: Entering directory `/home/iscsitarget-0.4.5/usr'
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o ietd.o ietd.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o iscsid.o iscsid.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o conn.o conn.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o session.o session.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o target.o target.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o message.o message.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o ctldev.o ctldev.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o log.o log.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o md5.o md5.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o isns.o isns.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o sha1.o sha1.c
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o chap.o chap.c
cc ietd.o iscsid.o conn.o session.o target.o message.o ctldev.o log.o md5.o isns.o sha1.o chap.o -o ietd
cc -O2 -fno-inline -Wall -Wstrict-prototypes -g -I../include   -c -o ietadm.o ietadm.c
cc ietadm.o ctldev.o -o ietadm
make[1]: Leaving directory `/home/iscsitarget-0.4.5/usr'
make -C /usr/src/kernels/2.6.9-42.0.3.EL-i686/ SUBDIRS=/home/iscsitarget-0.4.5/kernel modules
make[1]: Entering directory `/usr/src/kernels/2.6.9-42.0.3.EL-i686'
  CC [M]  /home/iscsitarget-0.4.5/kernel/tio.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/iscsi.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/nthread.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/wthread.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/config.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/digest.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/conn.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/session.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/target.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/volume.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/iotype.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/file-io.o
  CC [M]  /home/iscsitarget-0.4.5/kernel/target_disk.o
  LD [M]  /home/iscsitarget-0.4.5/kernel/iscsi_trgt.o
  Building modules, stage 2.
  MODPOST
  CC      /home/iscsitarget-0.4.5/kernel/iscsi_trgt.mod.o
  LD [M]  /home/iscsitarget-0.4.5/kernel/iscsi_trgt.ko
make[1]: Leaving directory `/usr/src/kernels/2.6.9-42.0.3.EL-i686'

# make install
`usr/ietd' -> `/usr/sbin/ietd'
`usr/ietadm' -> `/usr/sbin/ietadm'
if [ -f /etc/debian_version ]; then \
        install -v -m 755 etc/initd/initd.debian /etc/init.d/iscsi-target; \
elif [ -f /etc/redhat-release ]; then \
        install -v -m 755 etc/initd/initd.redhat /etc/init.d/iscsi-target; \
elif [ -f /etc/slackware-version ]; then \
        install -v -m 755 etc/initd/initd /etc/rc.d/iscsi-target; \
else \
        install -v -m 755 etc/initd/initd /etc/init.d/iscsi-target; \
fi
`etc/initd/initd.redhat' -> `/etc/init.d/iscsi-target'
install: creating directory `/lib/modules/2.6.9-42.0.3.EL/kernel/iscsi'
`kernel/iscsi_trgt.ko' -> `/lib/modules/2.6.9-42.0.3.EL/kernel/iscsi/iscsi_trgt.ko'
depmod -aq
#

Version 0.4.5 was released on 2005-02-21, so that PcPro article must have been on the editors desk for a year!

Ok, I still need to see if it will work, but that something for another post!