I wanted to see if I could get iSCSI tape workingi on fedora, it had been a while since I last tried and I thought maybe tape support had been introduced to Fedora by now. It is, although I had to compile from source.
Documented again as MHVTL installs much more cleanly in the latest version and works just perfectly; and I discovered mtx to manage the tape changer locally which is much easier.
As MHVTL is now on github installation is much easier if you have git already installed (if you don’t yet “yum install git git-core”).
On my iSCSI target, easy installation
Note: you cannot use /sbin/nologin for the vtl user, it must have a valid shell to work
cd ~mark mkdir -p git/mhvtl cd git/mhvtl git init git pull http://github.com/markh794/mhvtl.git cd kernel make cd .. make su - groupadd -g 900 vtl useradd -c "mvhtl user" -d /home/vtl -g vtl -m -s /bin/bash -u 900 vtl cd ~mark/git/mhvtl cd kernel make install cd .. make install
Running the service the first time (I just used status which was invalid, thats fine) creates default configuration files that define two tape changer devices with tape drives and a bunch of precreated tapes in the libraries.
[root@falcon mhvtl]# service mhvtl status
Could not locate library config file: /etc/mhvtl/library_contents.10
Creating a default one
Please stop mhvtl & edit /etc/mhvtl/library_contents.10 to suit your requirements
Could not locate library config file: /etc/mhvtl/library_contents.30
Creating a default one
Please stop mhvtl & edit /etc/mhvtl/library_contents.30 to suit your requirements
Usage: /etc/init.d/mhvtl {start|stop|shutdown}
[root@falcon mhvtl]#
[root@falcon etc]# cd /etc/mhvtl
[root@falcon mhvtl]# ls
device.conf library_contents.10 library_contents.30 mhvtl.conf
What the defaults are, as of July 2011 anyway, are device.conf defines two libraries, 10 (drive 11-14) and 30 (drive 32-34), library 10 has LTO4(E01001-E01020, slot 1-20)+LTO5(F01030-F01039, slot 30-39)+2 cleaning tapes (slot 22-23), library 30 has LTO4(E03001-E03020, slot 1-20)+LTO5(F03030-F03039, slot 30-39)+2 cleaning tapes (slot 22-23)
If you don’t have “lsscsi” installed you should install that as a matter of course, I don’t know why it’s not standard. For the tape changers MHVTL is going to provide you with you also need to install “mtx” if you want to issue commands to them as I found vtlcmd either didn’t work (or just didn’t make sense to me). So “yum install lsscsi mtx” now to save time later.
Before starting mhvtl
# lsscsi -g [root@falcon mhvtl]# lsscsi -g [0:0:0:0] disk ATA WDC WD1600AAJB-0 00.0 /dev/sda /dev/sg0 [1:0:0:0] cd/dvd SAMSUNG CD-ROM SC-152L C100 /dev/sr0 /dev/sg1 [1:0:1:0] cd/dvd CyberDrv CW068D CD-R/RW 120D /dev/sr1 /dev/sg2 [2:0:0:0] disk Maxtor Basics Desktop 0122 /dev/sdb /dev/sg3 [root@falcon mhvtl]#
Then start the mhvtl service and see what we have
[root@falcon mhvtl]# service mhvtl start vtllibrary process PID is 21111 vtllibrary process PID is 21115 [root@falcon mhvtl]# lsscsi -g [0:0:0:0] disk ATA WDC WD1600AAJB-0 00.0 /dev/sda /dev/sg0 [1:0:0:0] cd/dvd SAMSUNG CD-ROM SC-152L C100 /dev/sr0 /dev/sg1 [1:0:1:0] cd/dvd CyberDrv CW068D CD-R/RW 120D /dev/sr1 /dev/sg2 [2:0:0:0] disk Maxtor Basics Desktop 0122 /dev/sdb /dev/sg3 [3:0:0:0] mediumx STK L700 550V /dev/sch0 /dev/sg12 [3:0:1:0] tape IBM ULT3580-TD5 550V /dev/st0 /dev/sg4 [3:0:2:0] tape IBM ULT3580-TD5 550V /dev/st1 /dev/sg5 [3:0:3:0] tape IBM ULT3580-TD4 550V /dev/st2 /dev/sg6 [3:0:4:0] tape IBM ULT3580-TD4 550V /dev/st3 /dev/sg7 [3:0:8:0] mediumx SPECTRA PYTHON 550V /dev/sch1 /dev/sg13 [3:0:9:0] tape IBM ULT3580-TD4 550V /dev/st4 /dev/sg8 [3:0:10:0] tape IBM ULT3580-TD4 550V /dev/st5 /dev/sg9 [3:0:11:0] tape IBM ULT3580-TD4 550V /dev/st6 /dev/sg10 [3:0:12:0] tape IBM ULT3580-TD4 550V /dev/st7 /dev/sg11 [root@falcon mhvtl]#
Wasn’t that simple.
The next step is using it of course
The hard way to manually mount tapes is by using the mhvtl supplied command vtlcmd. That is so incredibly hard to figure out I suggest skipping that all together and installing mtx with a simply ‘yum install mtx’ command.
As using mtx is much simpler, and provides a lot more display output as to what is happening, all examples in here are using mtx.
The libraries installed became on my system (identified from the lsscsi command shown earlier) sg12 and sg13, these examples show how easy it is to use mtx to display the library and mount, use and unmount tapes in the autoloader using the tapes in the library.
[root@falcon kernel]# mtx -f /dev/sg12 status
Storage Changer /dev/sg12:4 Drives, 43 Slots ( 4 Import/Export )
Data Transfer Element 0:Empty
Data Transfer Element 1:Empty
Data Transfer Element 2:Empty
Data Transfer Element 3:Empty
Storage Element 1:Full :VolumeTag=E01001L4
Storage Element 2:Full :VolumeTag=E01002L4
Storage Element 3:Full :VolumeTag=E01003L4
Storage Element 4:Full :VolumeTag=E01004L4
Storage Element 5:Full :VolumeTag=E01005L4
Storage Element 6:Full :VolumeTag=E01006L4
Storage Element 7:Full :VolumeTag=E01007L4
Storage Element 8:Full :VolumeTag=E01008L4
Storage Element 9:Full :VolumeTag=E01009L4
Storage Element 10:Full :VolumeTag=E01010L4
Storage Element 11:Full :VolumeTag=E01011L4
Storage Element 12:Full :VolumeTag=E01012L4
Storage Element 13:Full :VolumeTag=E01013L4
Storage Element 14:Full :VolumeTag=E01014L4
Storage Element 15:Full :VolumeTag=E01015L4
Storage Element 16:Full :VolumeTag=E01016L4
Storage Element 17:Full :VolumeTag=E01017L4
Storage Element 18:Full :VolumeTag=E01018L4
Storage Element 19:Full :VolumeTag=E01019L4
Storage Element 20:Full :VolumeTag=E01020L4
Storage Element 21:Empty
Storage Element 22:Full :VolumeTag=CLN101L4
Storage Element 23:Full :VolumeTag=CLN102L5
Storage Element 24:Empty
Storage Element 25:Empty
Storage Element 26:Empty
Storage Element 27:Empty
Storage Element 28:Empty
Storage Element 29:Empty
Storage Element 30:Full :VolumeTag=F01030L5
Storage Element 31:Full :VolumeTag=F01031L5
Storage Element 32:Full :VolumeTag=F01032L5
Storage Element 33:Full :VolumeTag=F01033L5
Storage Element 34:Full :VolumeTag=F01034L5
Storage Element 35:Full :VolumeTag=F01035L5
Storage Element 36:Full :VolumeTag=F01036L5
Storage Element 37:Full :VolumeTag=F01037L5
Storage Element 38:Full :VolumeTag=F01038L5
Storage Element 39:Full :VolumeTag=F01039L5
Storage Element 40 IMPORT/EXPORT:Empty
Storage Element 41 IMPORT/EXPORT:Empty
Storage Element 42 IMPORT/EXPORT:Empty
Storage Element 43 IMPORT/EXPORT:Empty
[root@falcon ~]# mt -f /dev/st0 status
SCSI 2 tape drive:
File number=-1, block number=-1, partition=0.
Tape block size 0 bytes. Density code 0x0 (default).
Soft error count since last status=0
General status bits on (50000):
DR_OPEN IM_REP_EN
[root@falcon kernel]# mtx -f /dev/sg12 load 1 0
Loading media from Storage Element 1 into drive 0...done
[root@falcon ~]# mt -f /dev/st0 status
SCSI 2 tape drive:
File number=-1, block number=-1, partition=0.
Tape block size 0 bytes. Density code 0x46 (LTO-4).
Soft error count since last status=0
General status bits on (1010000):
ONLINE IM_REP_EN
[root@falcon kernel]# mtx -f /dev/sg12 status
Storage Changer /dev/sg12:4 Drives, 43 Slots ( 4 Import/Export )
Data Transfer Element 0:Full (Storage Element 1 Loaded):VolumeTag = E01001L4
Data Transfer Element 1:Empty
Data Transfer Element 2:Empty
Data Transfer Element 3:Empty
Storage Element 1:Empty
Storage Element 2:Full :VolumeTag=E01002L4
Storage Element 3:Full :VolumeTag=E01003L4
Storage Element 4:Full :VolumeTag=E01004L4
Storage Element 5:Full :VolumeTag=E01005L4
Storage Element 6:Full :VolumeTag=E01006L4
Storage Element 7:Full :VolumeTag=E01007L4
Storage Element 8:Full :VolumeTag=E01008L4
Storage Element 9:Full :VolumeTag=E01009L4
Storage Element 10:Full :VolumeTag=E01010L4
Storage Element 11:Full :VolumeTag=E01011L4
Storage Element 12:Full :VolumeTag=E01012L4
Storage Element 13:Full :VolumeTag=E01013L4
Storage Element 14:Full :VolumeTag=E01014L4
Storage Element 15:Full :VolumeTag=E01015L4
Storage Element 16:Full :VolumeTag=E01016L4
Storage Element 17:Full :VolumeTag=E01017L4
Storage Element 18:Full :VolumeTag=E01018L4
Storage Element 19:Full :VolumeTag=E01019L4
Storage Element 20:Full :VolumeTag=E01020L4
Storage Element 21:Empty
Storage Element 22:Full :VolumeTag=CLN101L4
Storage Element 23:Full :VolumeTag=CLN102L5
Storage Element 24:Empty
Storage Element 25:Empty
Storage Element 26:Empty
Storage Element 27:Empty
Storage Element 28:Empty
Storage Element 29:Empty
Storage Element 30:Full :VolumeTag=F01030L5
Storage Element 31:Full :VolumeTag=F01031L5
Storage Element 32:Full :VolumeTag=F01032L5
Storage Element 33:Full :VolumeTag=F01033L5
Storage Element 34:Full :VolumeTag=F01034L5
Storage Element 35:Full :VolumeTag=F01035L5
Storage Element 36:Full :VolumeTag=F01036L5
Storage Element 37:Full :VolumeTag=F01037L5
Storage Element 38:Full :VolumeTag=F01038L5
Storage Element 39:Full :VolumeTag=F01039L5
Storage Element 40 IMPORT/EXPORT:Empty
Storage Element 41 IMPORT/EXPORT:Empty
Storage Element 42 IMPORT/EXPORT:Empty
Storage Element 43 IMPORT/EXPORT:Empty
[root@falcon kernel]#
The mtx shows data transfer element 0 has a tape loaded available for use; I couldn’t figure out how to do that with vtlcmd. And it is easier to match the lsscsi output with devices rather than poke through the MHVTL config files to see whats where.
I was able to match up the drives simply by knowing I had no tape devices installed so /dev/st0 through /dev/st7 were the MHVTL tape devices (four per library) and that /dev/st0 (and I am assuming the next three) were for the first changer simply by writing/reading from /dev/st0.
Unloading from the drive back to a library slot is also as easy.
[root@falcon kernel]# mtx -f /dev/sg12 load 1 0
Additional Steps I had to do
This didn’t work. Possibly just SeLinux as noted below.
[root@falcon kernel]# tgtadm --lld iscsi --op new --mode target --tid 2 -T iqn.2010-01.us.nimsa:tgt:4:16:0:0:T [root@falcon kernel]# tgtadm --lld iscsi --op new --mode logicalunit --tid 2 --lun 1 --bstype=sg --device-type=pt -b /dev/sg13 tgtadm: invalid request
However One of the posts for configuring mhvtl on CentOS had a walk through for Centos that installed iscsi-target-utils (which in Fedora was 1.0.18 already, presumablt to get config files etc setup automatically) and then when that was installed manually pulled down and compiled stgt directly for the same 1.0.18 version to replace the fedora supplied one. So I tried that.
# install STGT yum install -y scsi-target-utils mkdir -p /usr/src/tgt cd /usr/src/tgt wget http://stgt.sourceforge.net/releases/tgt-1.0.18.tar.gz tar zxvf tgt-1.0.18.tar.gz cd tgt-1.0.18 make clean make make install chkconfig tgtd on service tgtd start
Then using exactly the same tgtadm commands as listed above that didn’t work origionally… same error; but after updating my Selinux rules it worked.
Note that It may have been SeLinux that caused the origional error above, it may actually work with the supplied RPM.
The additional selinux rules I had to add to my custom config to allow mhvtl virtual tape devices to be used were as below; it may not be all required as I have so many customised rules some other required rules may already exist in my selinux configurations.
require {
type tgtd_t;
class capability { sys_rawio sys_admin };
}
allow tgtd_t self:capability { sys_rawio sys_admin };
dev_manage_all_blk_files(tgtd_t)
