Mark,
the chandev layer is only for networking devices - it handles many things
including registering the
device with the networking layer. It does *not* drive dynamic device
recognition, but acts rather as
an in-between for the networking channel devices.
Dynamic device recognition is triggered by the machine check handler. If it
fails on 2.4, it is certainly
a bug somewhere.
Michal:
It sounds as if the freshly attached device was not correctly sensed by
Linux.
What kernel are you using? What does the entry for the tape say in
/proc/subchannels? If it says
something like "0000" or "FFFF" for CU type, could you please try to setup
a trace for the device
(#cp tr io <devno> inst int ccw run) and send me the output after the
attach?
Mit freundlichen Gr��en/Regards
Cornelia Huck
Linux for zSeries Development
IBM Deutschland Entwicklung GmbH
Email: [EMAIL PROTECTED]
Phone: ext. +49(0)7031/16-4837, int. *120-4837
|---------+---------------------------->
| | "Post, Mark K" |
| | <[EMAIL PROTECTED]|
| | m> |
| | Sent by: Linux on|
| | 390 Port |
| | <[EMAIL PROTECTED]|
| | IST.EDU> |
| | |
| | |
| | 07/06/02 06:07 PM|
| | Please respond to|
| | Linux on 390 Port|
| | |
|---------+---------------------------->
>---------------------------------------------------------------------------------------------------------------------------------------------|
|
|
| To: [EMAIL PROTECTED]
|
| cc:
|
| Subject: Re: tapes dynamical attache
|
|
|
|
|
>---------------------------------------------------------------------------------------------------------------------------------------------|
The tape driver does not support the chandev layer, so device detection is
only done at boot time. The same is true for a 2.2 kernel, since there is
no chandev layer at all. If you want to be able to use a tape drive on a
Linux/390 system, the tape must be attached to the guest at boot time. It
can later be detached and re-attached, but for device detection to happen
it
has to be there at boot.
It would be nice if the chandev layer support would be added to the tape
driver so that this would not be a problem. But, it's not there yet.
Mark Post
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Friday, July 05, 2002 8:08 AM
To: [EMAIL PROTECTED]
Subject: tapes dynamical attache
Hello:
I would like to dynamically add tapes to linux running under VM. If I
attache tape device to a virtual machine using for example
#cp att 330 * 181 and issue modprobe/insmod with specific tape adress - it
doesn't work (although it works fine, when I attache tapes and later reboot
linux).
What should I do?
Best regards
--
Pozdrawiam,
Michal Sierakowski
Department of Technology
PKO BP SA
Warsaw
