From: Ullrich_Fischer@mindlink.bc.ca (Ullrich Fischer)
Newsgroups: comp.sys.novell
Subject: BUSTEK 742A problem in Everex MegaCube
Date: 14 Apr 92 07:40:38 GMT
Article-I.D.: mindlink.11418
Organization: MIND LINK! - British Columbia, Canada

We've recently installed an EVEREX MEGACUBE 80486-33Mhz Novell 3.11A fileserver
with 32 Mb RAM and 5 GB of disk space spread over 9 physical drives (4 WREN IV
650 Mb, 2 WREN VI 960 Mb and 2 Conner 40 Mb SCSI drives).  The drives are split
5 drives on one BusTek controller, 4 on the other.  The controllers are EISA
32-bit bus mastering BusTek 742A rev H firmware 4.22. The driver is BTXNW31.DSK
V 1.0   We are duplexing the two 40 Mb drives as SYS: volume and another pair
of 650 Mb drives as APP volume.  The remaining drives are not mirrored or
duplexed.

When the system is lightly loaded, it works fine.  When it gets to around 40%
utilization and about 2000 dirty cache buffers, it comes up with volume
dismounted due to drive deactivation for one of the drives and shortly
thereafter drops the other drives.

One of the BusTeks has the bios enabled and also controlle the single 1.2 Mb
diskette drive in the system.

We've tried turning off the DMA on one or both of the controllers.  We've tried
turning off the 80486 internal and external cache (that made it worse).  We've
tried changing the interrupt on the BusTeks from edge triggering to level
triggering -- no effect.

I am now running the system with no problems using one DCB and one of the
BusTeks.

Is there anyone who has run into this one and solved it?  Why can't these
controllers co-exist?  Would I have the same problem with two DCBs? (We are
using garden variety ADIC DCB's (not the EDCB) cards in our other server and
have some spares.   I could put two DCBs in the MegaCube, but since these are
16 bit cards, I would expect to get less performance than with the BusTeks.
So far I've not observed any dramatic performance improvement from the BusTek.

In addition to the disk controllers, the other cards in the system are two
Gateway Ethernet EISA cards (in bus mastering slots), two ISA 16 bit PC550FS
SMC Arcnet cards in non-mastering EISA slots, and a herc clone video card in
the system's single 8-bit ISA slot.

With the BusTek/DCB combination we are seeing a large (up to 15 a minute)
number of 'primary interrupt controller reports a lost hardware interrupt'
messages.  With both BusTek cards installed, we get these messages for a while,
but when a certain load level is attained, we get a similar message from the
2ndary interrupt controller followd by one or two drives being disabled 'due to
drive failure' and then eventually all drives get dropped with the same
message.

I've spoken with Novell Tech support on this one.  They suggest playing with
the reserve buffers below 16 meg parameter in the start.ncf file.  I've looked
at this and it defaults to 16.  When I look at this resource on the monitor
screen, nothing seems to be useing these buffers.

I've got autoregister memory above 16 megabytes turned on in startup.ncf but
when the server boots, it says autoregister is already turned on.  In any case,
the monitor.nlm resources display shows that the server is aware of the full 32
Mb on the system.

thanks for any advice on this.
-uf
--
Ullrich_Fischer@mindlink.bc.ca
Newsgroups: comp.sys.novell,comp.sys.mac.system