2002-06-06 20:57:30

by Dag Nygren

[permalink] [raw]
Subject: Devfs strangeness in 2.4.18


Hi,
just installed a fresh Mandrake 8.2 here and am
seeing devfs behaving very strangely.
Here is some out put that shows the problems:

backup:dev 1004 % ls -ld sg*
drwxr-xr-x 1 root root 0 Jun 7 2002 sg
lr-xr-xr-x 1 root root 36 Jun 7 2002 sg0 ->
scsi/host0/bus0/target0/lun0/generic
lr-xr-xr-x 1 root root 36 Jun 7 2002 sg1 ->
scsi/host1/bus0/target1/lun0/generic
lr-xr-xr-x 1 root root 36 Jun 7 2002 sg2 ->
scsi/host1/bus0/target2/lun0/generic
lr-xr-xr-x 1 root root 36 Jun 7 2002 sg3 ->
scsi/host1/bus0/target3/lun0/generic
lr-xr-xr-x 1 root root 36 Jun 6 23:46 sg4 ->
scsi/host2/bus0/target2/lun0/generic
backup:dev 1005 % cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: IBM Model: DDRS-39130D Rev: DC1B
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: IBM Model: DCAS-34330W Rev: S65A
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi1 Channel: 00 Id: 01 Lun: 00
Vendor: ADIC Model: VLS DLT Rev: 0235
Type: Medium Changer ANSI SCSI revision: 02
Host: scsi1 Channel: 00 Id: 03 Lun: 00
Vendor: Quantum Model: DLT4000 Rev: CD3C
Type: Sequential-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 02 Lun: 00
Vendor: WangDAT Model: Model 3400DX Rev: 1.4a
Type: Sequential-Access ANSI SCSI revision: 02
backup:dev 1006 % ls -l /dev/st?
lr-xr-xr-x 1 root root 31 Jun 7 2002 /dev/st0 ->
scsi/host1/bus0/target2/lun0/mt
lr-xr-xr-x 1 root root 31 Jun 7 2002 /dev/st1 ->
scsi/host1/bus0/target3/lun0/mt

The problems are tha the sg? links doesn't correspond to the real
devices shown by /proc/scsi/scsi (Which matches the real situation)
sg0 matches the first disk, OK
sg1 matches the Medium changer, OK
sg2 matches nothing...... There is no target 2 on host1 !!!
sg3 matches the DLT tape drive
sg4 matches the DAT tape drive

The other problem is the st? links.
st0 is linked out into nothing ...

Seems like 3 host adapters is too much for devfs......
Do I need an upgrade ?

BRGDS

--
Dag Nygren email: [email protected]
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FINLAND



2002-06-06 22:14:52

by Ruth Ivimey-Cook

[permalink] [raw]
Subject: Re: Devfs strangeness in 2.4.18

On Thu, 6 Jun 2002, Dag Nygren wrote:

>The problems are tha the sg? links doesn't correspond to the real
>devices shown by /proc/scsi/scsi (Which matches the real situation)
>sg0 matches the first disk, OK
>sg1 matches the Medium changer, OK
>sg2 matches nothing...... There is no target 2 on host1 !!!
>sg3 matches the DLT tape drive
>sg4 matches the DAT tape drive
>
>The other problem is the st? links.
>st0 is linked out into nothing ...
>
>Seems like 3 host adapters is too much for devfs......
>Do I need an upgrade ?

In my experience, devfs doesn't create /dev/sg or /dev/st softlinks. The only
links it creates are from /dev/discs/... to /dev/ide/... or /dev/scsi/... as
appropriate.

I would look into the mandrake boot sequence in detail.

Ruth


--
Ruth Ivimey-Cook
Software engineer and technical writer.

2002-06-06 23:04:20

by Richard Gooch

[permalink] [raw]
Subject: Re: Devfs strangeness in 2.4.18

Ruth Ivimey-Cook writes:
> On Thu, 6 Jun 2002, Dag Nygren wrote:
>
> >The problems are tha the sg? links doesn't correspond to the real
> >devices shown by /proc/scsi/scsi (Which matches the real situation)
> >sg0 matches the first disk, OK
> >sg1 matches the Medium changer, OK
> >sg2 matches nothing...... There is no target 2 on host1 !!!
> >sg3 matches the DLT tape drive
> >sg4 matches the DAT tape drive
> >
> >The other problem is the st? links.
> >st0 is linked out into nothing ...
> >
> >Seems like 3 host adapters is too much for devfs......
> >Do I need an upgrade ?
>
> In my experience, devfs doesn't create /dev/sg or /dev/st softlinks.

Indeed. It's devfsd that creates it.

> The only links it creates are from /dev/discs/... to /dev/ide/... or
> /dev/scsi/... as appropriate.
>
> I would look into the mandrake boot sequence in detail.

Also check that you don't have bogus entries in your dev-state
area. Mandrake had some configuration problems a few months back.

Regards,

Richard....
Permanent: [email protected]
Current: [email protected]

2002-06-07 07:46:35

by Dag Nygren

[permalink] [raw]
Subject: Re: Devfs strangeness in 2.4.18

> Ruth Ivimey-Cook writes:
> > On Thu, 6 Jun 2002, Dag Nygren wrote:
> >
> > >The problems are tha the sg? links doesn't correspond to the real
> > >devices shown by /proc/scsi/scsi (Which matches the real situation)
> > >sg0 matches the first disk, OK
> > >sg1 matches the Medium changer, OK
> > >sg2 matches nothing...... There is no target 2 on host1 !!!
> > >sg3 matches the DLT tape drive
> > >sg4 matches the DAT tape drive
> > >
> > >The other problem is the st? links.
> > >st0 is linked out into nothing ...
> > >
> > >Seems like 3 host adapters is too much for devfs......
> > >Do I need an upgrade ?
> >
> > In my experience, devfs doesn't create /dev/sg or /dev/st softlinks.
>
> Indeed. It's devfsd that creates it.
>
> > The only links it creates are from /dev/discs/... to /dev/ide/... or
> > /dev/scsi/... as appropriate.
> >
> > I would look into the mandrake boot sequence in detail.
>
> Also check that you don't have bogus entries in your dev-state
> area. Mandrake had some configuration problems a few months back.

Yess!!!
That's what did it, removing the sg? and st? entries from /lib/dev-state
did the trick. There were some oldies ghosting there. Thanks a lot
Richard, I didn't even know that there was a dev-state directory to
look for ;-).
Is there any comprehensive documentation on devfsd and devfs anywhere
on the net? Could be good to read a bit more about this.

BRGDS

Dag


2002-06-07 16:34:54

by Richard Gooch

[permalink] [raw]
Subject: Re: Devfs strangeness in 2.4.18

Dag Nygren writes:
> > Also check that you don't have bogus entries in your dev-state
> > area. Mandrake had some configuration problems a few months back.
>
> Yess!!!
> That's what did it, removing the sg? and st? entries from /lib/dev-state
> did the trick. There were some oldies ghosting there. Thanks a lot
> Richard, I didn't even know that there was a dev-state directory to
> look for ;-).

I've added an item to the FAQ about this.

> Is there any comprehensive documentation on devfsd and devfs
> anywhere on the net? Could be good to read a bit more about this.

Have you not looked at the FAQ?

Regards,

Richard....
Permanent: [email protected]
Current: [email protected]

2002-06-10 07:43:30

by Dag Nygren

[permalink] [raw]
Subject: Re: Devfs strangeness in 2.4.18

> Dag Nygren writes:
> > > Also check that you don't have bogus entries in your dev-state
> > > area. Mandrake had some configuration problems a few months back.
> >
> > Yess!!!
> > That's what did it, removing the sg? and st? entries from /lib/dev-state
> > did the trick. There were some oldies ghosting there. Thanks a lot
> > Richard, I didn't even know that there was a dev-state directory to
> > look for ;-).
>
> I've added an item to the FAQ about this.

A very good idea.

> > Is there any comprehensive documentation on devfsd and devfs
> > anywhere on the net? Could be good to read a bit more about this.
>
> Have you not looked at the FAQ?

Yes, but looking for sg and st stuff I didn't looh that carefully.
What I was missing at that time was a walkthrough of the
devfs and devfsd default operations.

Anyway it work beatifully now.
Thanks again

Dag