last update: 29 / november / 2002
GNU/Linux and autoloader 2nd act...
[Some months ago I wrote an article (Pluto Journal n° 37) about an
autoloader installation experience on an IBM with a Red Hat 6.2. GNU/Linux.
Now, after an upgrade, to Red Hat Linux 7.2 (and subsequently to 7.3), I found
some problems. In detail the robotic part of autoloader was no more detected
from the system.
Once again I face with an expansive backup unit where it was necessary to change
the tapes manually.]
The situation seemed impossible to resolve for many reasons. Last (but
not least) the necessity of a 24x7 availibility of the server (and therefore
it was impossible for me to test the solutions)and the fact that neither IBM
nor Red Hat gave concrete answer (after I interpellate They on the argument).
Beyond that I began to receive mails from people that, after to have read the
first article, asked me suggestions in order to resolve the same problem I
found on my server.
A mail exchange with one of these persons (Massimo Albonetti) has created a collaboration through the web. Then some of my suggestions, his tests and his patience has carried us to the solution. Massimo has subsequently written the notes that follow (and that I have soon tried to introduce) in order to help all those who are in the same trouble. Following his words and his experience:
After the Red Hat 7.3 setup has been completed, autoloader unit, was detected
as a standard DDS type, it was possible to backup files through the command
tar cvf /dev/st0 but it was impossible to drive the 'change' device.
here the steps I followed to let work the DDS/4 Autoloader 120/240GB installed in an
IBM 255 @server with Red Hat 7.3.
If at boot it appear a message like:
00 B 6 0 SEAGATE DAT06241-XXX 80.0 16 00 B 6 1 SEAGATE DAT06241-XXX 80.0 16the scsi card is correctly configured, if instead You get a message like:
00 B 6 0 SEAGATE DAT06241-XXX 80.0 16it is necessary to enter in the scsi card bios setup (usually pressing Ctrl-A at boot) and to config correctly the scsi controller
Step 2 After server is started, if kernel is correctly configured, You should type command
cat /proc/scsi/scsiand get a message like
Host: scsi1 Channel: 00 Id: 06 Lun: 00 Vendor: SEAGATE Model: DAT 06241-XXX Rev: 8240 Type: Sequential-Access ANSI SCSI revision: 03 Host: scsi1 Channel: 00 Id: 06 Lun: 01 Vendor: SEAGATE Model: DAT 06241-XXX Rev: 8240 Type: Medium Changer ANSI SCSI revision: 03if, instead, You get
Host: scsi1 Channel: 00 Id: 06 Lun: 00 Vendor: SEAGATE Model: DAT 06241-XXX Rev: 8240 Type: Sequential-Access ANSI SCSI revision: 03it means that kernel is not correctly configured and is unable to detect Media Changer unit. So it is necessary to rebuild kernel and to enable the parameter
CONFIG_SCSI_MULTI_LUN=y
Step 3 To this point kernel should detect Media Changer but hat no driver ready for it. It is necessary to download driver from http://www.strusel007.de/linux/changer.html. To install driver You must path kernel to let it load scsi driver setting the parameter
CONFIG_CHR_DEV_SCH=mrebuild Kernel and autoloader should work correctly: using software commands it is possible to drive unit.
According some other instructions Massimo send me, mtx command doesn't run because it searches for device /dev/sg , instead /dev/sch We use.
But in the driver package there are some programs tho manage media changer.
I hope these short notes may Help You to solve Your problems with autoloaders. For what it concern to me they are a beautiful example of how it is possible to work togheter through internet and open source software.
