Re: max_scsi_luns and 2.4.19-pre10.

[Austin Gonyou <austin@digitalroadkill.net>]

On Wed, 2002-06-26 at 11:07, Kurt Garloff wrote:
> Hi Austin,
> 
> On Wed, Jun 26, 2002 at 09:18:45AM -0500, Austin Gonyou wrote:
> > On Wed, 2002-06-26 at 07:33, Kurt Garloff wrote:
> > > enough guesses have been there not answering your questions ...
> > 
> > Sure I hear that. But I posted an earlier question about QLA2200 and a
> 
> You don't think that somebody who reads your message and tries to post a
> helpful comment scans the list for earlier messages of yours, do you?
> 
Well, I do, especially if someone says it's an urgent thing to try and
get the whole story. If I don't have time, I'll ask someone to give more
info, which you did and I respect that and thank you.

> > PV 660F and not seeing > 8 luns with 2.4.19-pre10.
>   ^^^^^^^
> 
> This device needs BLIST_LARGELUN.

I got that from your earlier post and addressed it directly. Thanks for
the pointer. I didn't know the 660 was defined explicitly in the
scsi_scan.c I've since recompiled several kernel versions to assert this
as being true with the BLIST_LARGELUN option and it's definitely fixed
my problems there.

> > I'll take a look at that, and see if I can merge it into -aa4. 
> 
> The patch should be in there, just not the additional devices that need
> BLIST_LARGELUN.
> 
> > > The flag does allow a device to use more than 8 LUNs despite it reporting
> > > as SCSI Version 2 devices (which can not support more than 8 LUNs normally
> > > ...) 
> > > The flag also needs to be set for some more devices, look for DGC, DELL, CMD
> > > and CNSi/CNSI devices that already have the BLIST_SPARSELUN flag.
> > 
> > This would be a DELL device, so I'll see about changing it from
> > SPARESLUN to LARGELUN?
> 
> No. Add " | BLIST_LARGELUN" .


Yep, Did that. Again Thanks!

> > > But as you did not post the output of /proc/scsi/scsi nor the syslog
> > > meesages from your SCSI subsystem nobody knows what devices you're using or
> > > what actually happens. Just speculations ...
> > 
> > There's nothing to post from /proc/scsi/scsi or the syslog other than
> > there's no more than 8 devices on my FC chain. I guess the real point
> > here is that if you're using FC, you're probably going to use more than
> > 8 luns, even if not immediately. Especially for large Databases. 
> 
> People could have seen what SCSI device you're using.
> So I could have told you instead of guessing and risking to add to the noise
> myself.

I hear you loud and clear. I wouldn't have made so much noise myself had
it not been a *top* priority item that I couldn't find info on anywhere
else, plus the boss putting pressure too. Soon, this system will be a
6650 with PV 660F, 8GB RAM, using Linux with Oracle8.1.7.2, XFS, 0(1)
scheduler and nearly a TB of total DB. 

I have some results from my benchmarking which are quite astounding too.


> Regards,
> -- 
> Kurt Garloff  <garloff@suse.de>                          Eindhoven, NL
> GPG key: See mail header, key servers         Linux kernel development
> SuSE Linux AG, Nuernberg, DE                            SCSI, Security
-- 
Austin Gonyou <austin@digitalroadkill.net>