Blast from the past II: presenting a LUN to a 4.0F box

[Adam Garsha]

After presenting a LUN to a 4.0F box, how did you create device files?

[Ivan Ferreira]

I used to start with genvmunix, recompile the kernel and device files where created automatically.

[Hein van den Heuvel]

There was a MAKEDEV script in /dev no?

Then use 'file' to see whether you can really see the device and disklabel to make is useable.

Hein.

[Ivan Ferreira]

To issue the MAKEDEV, you need to know the device name that the device would have. That's why I use to do the log way.

[Vladimir Fabecic]

Based on my answer on your previous question:
Calculate device name and make device file using MAKEDEV.
For example
BUS 4 ID 1 LUN 1
# cd /dev
# ./MAKEDEV rza33*
As Hein said check with file command did you create device file OK.
When you present LUN to TRU64 V4.0F box you also define which LUN will be assigned.

[Adam Garsha]

1st are you sure that LUN0 doesn't equal rza?

2nd, does reboot automatically create files?
Do I need to scan scsi bus somehow?

Thanks.

[Hein van den Heuvel · Accepted solution]

>> 1st are you sure that LUN0 doesn't equal rza?

Pretty sure. That's how I remember it also.
Basically the lun support came late. Originally OSF only had bus + unit. Then support for luns was added and a new naming convention was developped to be compatible with the existing lun-less and thus 'a' less naming.


>> 2nd, does reboot automatically create files?

Yes, but like Ivan says, you need to boot genvmunix, not your own /vmunix kernel. They rebuild, and reboot for a second time with the fresh kernel and fresh device files.

>> Do I need to scan scsi bus somehow?

Not if you go the long, but predictable, genvmunix route.

Hein.

[Vladimir Fabecic]

>> 1st are you sure that LUN0 doesn't equal rza?
I am 100% sure!!!
Take a look at "normal" systems with only internal SCSI disks. Every SCSI disk connected to "normal" SCSI controller has LUN 0!!! So that is why these disks are called rz1, rz2 etc, NOT rza1, rza2 etc!!!
Once again:
LUN 0 has NO ADDITIONAL LETTER, LUN 1 has letter a (rza8 is BUS 1 ID 0 LUN 1), LUN 2 has letter b ...
I never reboot UNIX systems when I do not have to! UNIX is NOT MS windows!
But you can also do what Ivan said, it will work.

[Vladimir Fabecic]

For future questions about adding disks to a running 4.0F box:
1. Create and present new "disk"
2. Do:
# scu scan edt
and
# scu show edt
to verify OS has found "new disk"
3. Calculate device name from formula:
rzX ((SCSI ID) + (Bus number X 8))
where X is additional letter for LUN number
where LUN 0 has NO ADDITIONAL LETTER, LUN 1 is letter "a", LUN 2 is letter "b" etc
example: BUS 1 ID 1 LUN 1 is rza9
3. Create device files for "new disk"
# cd /dev
# ./MAKEDEV rzXY (./MAKEDEV rza9*)
4. Check everything is OK using "file" command.
5. Be happy it is UNIX and label the "new disk"

[Joris Denayer]

Hi,

If you only add a new device on an existing SCSI bus (or if you configure a new unit in an existing HSZ/HSG).

2 possibilities exist

- the MAKEDEV tool (already explained)
- simply reboot. It is not necessary to reboot from genvmunix. There is no new device driver needed for a new disk on an existing bus. (Otherwise, running MAKEDEV without rebooting wouldn't work). In fact, all busses are scanned during startup, when the device driver is activating an adapter.
This can be seen in the startup messages.


You only have to reboot from genvmunix if your configuration is changed. f.i.
- a new SCSI adapter is added
- an existing adapter is moved to another slot

[Martin Moore]

I respectfully disagree with Vladimir: rz33 and rza33 are equivalent! Both are bus 4, target 1, lun 0. At the SRM console, this would be DKE100. The naming format for the console is:

DK = SCSI disk device
E = SCSI bus indicator (A=0, B=1, ... E=4)
1 = SCSI target ID
0 (first one) = always zero
0 (second one) = LUN number

Then on the Tru64 side, compute (8 * bus number) + target = (8*4)+1 = 33. For LUN 0, we use letter a _or_ no letter.

If you want to verify that rza33 and rz33 are equivalent, here's a simple test. Use MAKEDEV to create rz33, rza33, and rzb33, then "ls -l" on the resulting device special files. You'll see that rz33 and rza33 have the _same_ major and minor numbers, but rzb33 has a different minor number. rz33 and rza33 are the same device.

Martin