SCSI tape drive problem

[Jackson Chen]

Dear,

I had a SCSI tape unit(SureStore 40e) and SCSI card(DPT-PM3334UW) on RedHat Linux 6.2.
I can't find the device in /proc/scsi/scsi.

Then I moved them(tape unit and scsi card) to another RedHat Linux 6.2, I could find the tape unit info in /proc/scsi/scsi.

Does someone know what's the problem that I encountered ? Or where I need to check to see more detail info ?

Thanks a lot !

Jackson

[Paulo A G Fessel]

This means either one of three things:

1) The first server has no driver configured for DPT card and thus can't see the SCSI tape;

2) The first server didn't autoload the SCSI board driver and its modules, something that has been addressed in the second machine.

3) The second server has support to both card and tape drive built into the kernel - that is, DPT and ST drivers are compiled as parts of the kernel and not modules.

In the first and third cass, you must recompile your kernel to add support to both the SCSI board and SCSI tape. Look for "EATA ISA/EISA?PCI" (CONFIG_SCSI_EATA) for DPT Card and "SCSI Tape Support" (CONFIG_CHR_DEV_ST) for Tape Support. Use "Y" instead of "M" to force the drivers to be compiled into the kernel.

In the second case, verify "/etc/modules.conf" to see if there is any mention of ST and DPT drivers. Then copy the definitions into the first machine.

HTH
Paulo Fessel

[Jackson Chen]

Dear Paulo,

Many thanks for your input.

The first server worked perfectly with the scsi card and tape unit few weeks ago.

Then I installed the TapeWare software for Linux(shiped with HP tape unit) and used it to make several backup successfully.

From 2 weeks ago, the RedHat Linux could not detect the tape unit.

I had checked the two RedHat Linux boxes, they have the same /etc/conf.modules :
------------------------------------
alias eth0 3c59x
alias parport_lowlevel parport_pc
alias scsi_hostadapter eata
------------------------------------

Do you have other ideas ?

best regards

Jackson

[Steven E. Protter]

If the tape drive is certified with Linux, it should have instructions on how to integrate it into the kernel.

Since it worked in a different machine you probably don't have a compatiability issue.

HP does test the tape units with various scsi cards.

Red Hat 6.2 is getting a little old and if the tape drive was created after Red Hat 6.2 the manual procedures outlined in the first post are the only way to go.

What does the surestore certification matrix say?

I would also check on the first machine if there isn't already a scsi card with the same scsi id in the box. Not likely but possible.

SEP

[Paulo A G Fessel · Accepted solution]

Ok.

The first thing you should do is certify yourself whether both your installations use modules or not. It seems from your /etc/modules.conf that they do use them.

Then, check your /lib/modules//modules.dep file and check dependencies for st module. They should be the same on both machines. Also, try issuing a "modprobe st" command at the faulted server. Something similar to this should appear:

QLogic ISP1020 SCSI on PCI bus 00 device 5
8 irq 10 MEM base 0xd2900000
st: Version 20020805, bufsize 32768, wrt 30720, max init. bufs 4, s/g segs 16

(Of course, this is from my hardware, and the messages may vary, but you should see a message from st driver informing that it's been attached to the system.)

It will also be interesting to notice whether your SCSI controller or SCSI tape show up before starting up TapeWare. This is because the st module may not be loaded unless requested by TapeWare.

Make these tests and let us know.

[]'s
Paulo Fessel

[Jackson Chen]

Dear Paulo,

Quite good anwser!

1. both of the installation use modules.

2. the dependencies for st module are the
same in both Linux boxes:
---------------------------------------------
/lib/modules/2.2.14-5.0/net/hostess_sv11.o: /lib/modules/2.2.14-5.0/net/z85230.o /lib/modules/2.2.14-5.0/net/strip.o:
/lib/modules/2.2.14-5.0/scsi/st.o: <--- here
/lib/modules/2.2.14-5.0/scsi/ultrastor.o:
/lib/modules/2.2.14-5.0/misc/dstr.o: /lib/modules/2.2.14-5.0/misc/paride.o
----------------------------------------------
does it mean there is no dependency for st ?

3. I tried to load st modules manually, here is the output :
----------------------------------------------
[root@lttrs02 2.2.14-5.0]# modprobe st
Note: /etc/conf.modules is more recent than /lib/modules/2.2.14-5.0/modules.dep
[root@lttrs02 2.2.14-5.0]# lsmod
Module Size Used by
st 24556 0 (unused)
ide-scsi 7080 0
lockd 30344 1 (autoclean)
sunrpc 52132 1 (autoclean) [lockd]
3c59x 18980 1 (autoclean)
----------------------------------------------
I don't understand the term "unused" means.

I also attached the output of dmesg for your good reference:
----------------------------------------------
3c59x.c:v0.99H 11/17/98 Donald Becker eth0: 3Com 3c905C Tornado at 0x1000, 00:50:04:bc:2b:2e, IRQ 11
8K byte-wide RAM 5:3 Rx:Tx split, autoselect/Autonegotiate interface.
MII transceiver found at address 24, status 782d.
Enabling bus-master transmits and whole-frame receives.
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
scsi : 1 host.
st: bufsize 32768, wrt 30720, max buffers 4, s/g segs 16.
scsi : 1 host.
----------------------------------------------

Before using TapeWare, I use tar to backup my Oracle dump file on that RedHat Linux for several months. After TapeWare installation, I also use it to perform some backup. Now, the /dev/st0 was not seen and both tar and TapeWare were stopped.

Thanks a lot for your kindly support !

Jackson

[Paulo A G Fessel]

Your Red Hat is old... 6.2 doesn't include devfs, and so I can't send you the setup I used home in my DAT-DDS3. BTW, I'm backing my machine now with Arkeia Lite, so it works.

Anyway, you can ever load the scsi module into your initrd. Just remake your existing initrd adding these switches:

"--with scsi_mod --with=eata --with=st"

The switches must appear in this order, as this is the order that the drivers will follow when the initrd loads.

Try to do this in the faulted server. If it works, you can use this setup in the working server too.

HTH
Paulo Fessel

[Jackson Chen]

Dear Paulo,

Many thanks for your reply.

I knew RedHat 6.2 was old, but I could not install Oracle8i in a newer version like Redhat 7.3 or 8 .... or 9.

I found that the /proc/pci displayed my SCSI card info correctly :
-----------------------------------------------
Bus 1, device 13, function 0:
SCSI storage controller: DPT SmartCache/Raid (rev 2).
Medium devsel. BIST capable. IRQ 11. Master Capable. Latency=64. Min Gnt=4.Max
Lat=8.
I/O at 0x1080 [0x1081].
-----------------------------------------------
so, the problem might be tape unit modules?
but even I loaded st module, I could not use tar to backup.
Besides, the tape unit works in another RedHat.

Would you explain more detail how to apply initrd ? Because I could not find this fine or someting like this.

best regards

Jackson

[Jackson Chen]

I had read one article on the web, illustrate something related to Linux-SCSI-tape. Here is the content :
----------------------------------------------
Assuming this is a scsi tape drive, here are a few things to check to try and find out why your software isn't seeing the drive:

- is a scsi driver for your SCSI interface card loaded? To access a tape drive you need the driver for your particular interface, the low level scsi driver, and the scsi tape driver. As root, you should be able to do `/sbin/modprobe st`, which will load all of these drivers for you. Afterwards, do a `/sbin/lsmod` and make sure drivers were
loaded. Also, `dmesg` may say something - if your scsi interface driver was loaded as a result of these commands, the driver will probe
the SCSI bus and should report on any devices it finds.

- `cat /proc/scsi/scsi` will list all scsi devices on your system (assuming the drivers are loaded). Here's an example:

[djholm@stkenmvr3a djholm]$ cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 01 Lun: 00 Vendor: STK Model: 9840 Rev: 1.28
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi3 Channel: 00 Id: 01 Lun: 00 Vendor: STK Model: 9840 Rev: 1.28 Type: Sequential-Access ANSI SCSI revision: 03

Both of these are tape drives. `ls /proc/scsi` will also show any
scsi interfaces:

[djholm@stkenmvr3a djholm]$ ls -l /proc/scsi
total 0
dr-xr-xr-x 2 root root 0 Oct 22 13:34 aic7xxx
-rw-r--r-- 1 root root 0 Oct 22 13:34 scsi

In this case this machine has an Adaptec interface, which uses the aic7xxx driver.

If your DAT drive isn't listed in /proc/scsi/scsi, there's likely a cabling or termination problem. You might try going into the BIOS screen for your SCSI adapter (for Adaptec, I think you hit 'alt-A'
during booting) and checking whether the adapter can see the device.

- if you've found your DAT listed in /proc/scsi/scsi, you should be able
to interact with it via 'mt' commands. The first scsi tape drive is accessed via /dev/st0 or /dev/nst0. As root, try
`mt -f /dev/nst0 status`
to see whether your system can send a command to the device. If the command fails, use `dmesg` to see what errors were posted. If the command times out, there could be an interrupt conflict, bad or misused PCI slot, etc...


For SCSI tape drives, you must be able to do the things listed above or
your backup software will not work.

Don Holmgren
Fermilab
----------------------------------------------

I have my scsi card detected by OS (/proc/pci)

I have my tape unit detected bu scsi card BIOS
(scsi id 4, detected by scsi card BIOS)

I am sure the cabling and SCSI terminating
was correct(I moved them to another server
and they work fine)

But the tape was not detected by OS, even I
loaded st modules ........

Any tips ?

thanks & best regards

Jackson

[Huc_1]

mkinitrd is the command you are looking for.

have a look at man mkinitrd nothing to it realy.

one more thing what does the command mt reply ?

# mt -f /dev/st0 status

and do you see the tape from dmesg ?

J-P

[Paulo A G Fessel]

You should take care about the order you're loading modules. You must load in this order:

1. scsi_mod (SCSI linux abstraction layer)
2. eata (SCSI driver)
3. st (SCSI tape driver)

You can arrange this dependency in /etc/modules.conf file. Just add the line

pre-install st modprobe eata

which will load the SCSI board driver automatically when you issue a "modprobe st".

THIS SHOULD WORK. If it doesn't, there may be a problem with your hardware, or even IRQ conflicts. Confirm also that there is no IRQ sharing with ISA cards; my home system locked up yesterday because one ISA card had been set up for IRQ 9 and was getting IRQ 7.

[Paulo A G Fessel]

You should take care about the order you're loading modules. You must load them in this order:

1. scsi_mod (SCSI linux abstraction layer)
2. eata (SCSI driver)
3. st (SCSI tape driver)

You can arrange this dependency in /etc/modules.conf file. Just add the line

pre-install st modprobe eata

which will load the SCSI board driver automatically when you issue a "modprobe st".

THIS SHOULD WORK. If it doesn't, there may be a problem with your hardware, or even IRQ conflicts. Confirm also that there is no IRQ sharing with ISA cards; my home system locked up yesterday because one ISA card had been set up for IRQ 9 and was getting IRQ 7.

[Jackson Chen]

Dear,

I tried it with another way.

First, I changed the DPT scsi card to Adaptec 29160N and kept tape unit unchanged.

Then, I modified this line in /etc/conf.modules
<>
alias scsi_hostadapter eata
<>
alias scsi_hostadapter aic7xxx
and then reboot

After that, I loaded 2 modules manually:

modprobe aic7xxx
modprobe st

and I could see my tape unit, use the device to perform the backup successfully !

I found that the ide-scsi module occupied sscsi0, 29160N and HP tape unit occupied scsi1.

My problem is : how could I get the DPT scsi card work with HP tape unit ? They worked together on this RedHat in the past and they work fine in another RedHat 6.2 now !!

Is this problem related to modules ?
----------------------------------------------
<>
alias eth0 3c59x
alias parport_lowlevel parport_pc
alias scsi_hostadapter eata
<

>
Module Size Used by
ide-scsi 7080 0
lockd 30344 1 (autoclean)
sunrpc 52132 1 (autoclean) [lockd]
3c59x 18980 1 (autoclean)
----------------------------------------------

best regards

Jackson

[Paulo A G Fessel]

I don't think so. If the only thing you have changed is the driver (eata to aic7xxx) and the tape drive was detected it seems obvious to me that the problem lies on your DPT card. One sounding evidence of this is the fact that even with eata driver loaded you can't see your tape drive.

I suggest you to check the card configuration that is shown during the server POST. Verify that bus speed is correct, if the device allows disconnection and if the drive is detected by the POST program of the board.

Check also if there are bended pins on the cable(s). This may affect your operation too.

Finally, if the firmware of the board is upgradeable, you may try to update it. I don't recommend flashing your tape drive, as it was (and is) working normally with the Adaptec 29160.

Good luck,
Paulo Fessel

[Jackson Chen]

Dear Paulo,

Thanks for your reply.

The DPT card works fine and the OS could detect it under /proc/scsi. Actually it worked very well in this server few weeks ago and it also works in another RedHat 6.2 without PIN/CABLE/TERMINATOR problem.

Like my prevous post, I just changed the moudle from eata to aic7xxx and load st again, it works. Does it mean my eata module has problem ?

best regards

Jackson

[Paulo A G Fessel]

If your card gets detected then there is no problem with your DPT card.

If you're getting too many troubles with your setup, I suggest you to grab an Adaptec 2940 card. They are cheap these days and are proven technology - I've got one for my DAT3 drive and I haven't had a single glitch.

Also, it is not clear if you're sharing the card's bus with other devices, but it is a best practice keep the tape drive alone (or at least in a exclusive bus of your SCSI card), as tape drives may overload the bus.

Are you absolutely sure that there were no changes on DPT card configuration? Could you configure the card for factory defaults and see what happens?

HTH
Paulo Fessel

[Jackson Chen]

Dear Paulo,

Thanks for your continually input.

I tried to change back to DPT card and manually loaded :

modprobe eata
modprobe st

and then I could use the DPT card and HP tape unit to backup again !

Why my /etc/conf.modules not loaded the modules correctly ? Should I check something in my system ?

best regards

Jackson

[Paulo A G Fessel]

Well, /etc/conf.modules is deprecated - nowadays all of us use /etc/modules.conf.

I think that's interesting to check your modutils version - AFAIK, even the latest version of modutils in RH6.2 uses /etc/modules.conf instead of /etc/conf.modules.

[]'s
Paulo Fessel