[SunRescue] Re: Trolls and MP on rescued suns

[Gregory Leblanc]

> -----Original Message-----
> From: Bjorn Ramqvist [mailto:brt at osk.sema.se]
> 
> Ken Hansen wrote:
> 
> <snip>
> 
> > On my SS5/70 I run Linux, on my Ultra2/300 I run Solaris - 
> other machines
> > vary (notably, I also run SOlaris 2.6 on my SPACRbook 3GX, 
> an SS5/110-kina
> > machine w/64 Meg RAM, but that is because Solaris 2.6 
> supports the hardware
> > better than Linux - note, I have not tried *BSD on it yet...).
> > 
> > So, if you have an Ultra, Solaris my be better - if you 
> have a Sun4M (SS2,
> > SS5, SS10/20, LX, etc.) Linux may be a better platform. SMP 
> SS10/20s may do
> > better under an older Solaris (like R2.5.1 or 2.6).

Slightly tangential, but the SS2 is NOT sun4m, but rather sun4c.

On my SS2s, I've found both that neither Linux (redhat) nor Solaris (7)
perform up to my expectations.  OpenBSD is ok on one machine, and I've got
another machine where I'll be trying netBSD, in my vast amounts of free
time.  ;)  I've found the SMP performance of Linux to be adequate, on a dual
processor machine.  Having a working system out of the box is another nice
plus (it takes me a few hours to install the software that I want onto
Solaris), but Solaris has a more professional feel to it. 

> A side-note here;
> I don't know the status of current kernels, distributions what-so-ever
> related to Linux, but I was recently in a situation where I needed the
> MD (Multiple Devices driver, RAID-support) under Linux on SPARC. Tried
> installing RedHat 6.2, just for fun, at home on my SS5/70 which went
> good.
> After that, I tried installing on SS5/170, which made me sad. 
> The kernel
> paniced upon me and overall it was really unstable and buggy, which
> forced me over to Solaris again.
> Same thing with a SS20/501. The kernel went fine, all the way until I
> started using the RAID-features. Then the whole system 
> paniced a couple
> of times, and was generally unstable.

Are you talking about the MD drivers, or the RAID drivers?   RedHat 6.x
ships with the RAID drivers, which are a complete re-write from the MD
drivers.  Unfortunately, there is an endian-issue with persistent
superblocks, which can cause some weird things.  There have been a couple of
fixes, and I think that 2.2.16-3 incorporates one of these fixes.  I'll
check the notes for the RH 7 kernel RPMs.  The SS5/170 is also a "weird"
machine, as it's the only TurboSPARC.  Since there aren't any other machines
based on that processor, development and testing isn't as readily done.

> All of this, in opposite of my SS5/70, makes me wonder if 
> Linux/SPARC is
> generally a good idea (so far) on sun4m machines. I tried a 
> newer kernel
> at that time, but without any better result.
> Same thing there, it went for Solaris instead.

Right now, support for the SCSI controllers on sun4m boxes is slow, like
pouring molasses in January in New England.  The only reason that I keep
Linux on my SS20 is that Solaris doesn't have ANY support for a half-way
decent and useable console, and X is painful at 8-bit.

> Another thing; RedHat installation program failed due to _too many_
> connected disk devices. For some reason, it couldn't handle 
> all of my 4
> trays with 6 disks in each. (4 x 6 = 24 disks)
> If I look at the SSA's, this is a serious problem, where in an SSA you
> can hose up to 30 disks.
> Looks like the o'so-enterprise RedHat can't handle more than 20 or so
> disks...
> (I have no clue)

Yikes, that's a boatload of disks.  I don't even own that many disks between
all of my machines.  Actually, I installed a CDROM tower with 28 SCSI CDROM
drives in it.  How many disks were you trying to configure at install time?
I'm sure that their installers is brain-dead, but I've been able to get
around the stupid thing once the system is up and running.  (on a side note,
Debian's installer is even more brain dead, and either of those two make
OpenBSD's package system look like something from the stone ages)  Later,
	Greg