[1055] in linux-scsi channel archive
Re: news on dual buslogics with MD
daemon@ATHENA.MIT.EDU (Douglas Warren)
Tue Dec 3 11:02:13 1996
To: submit-linux-dev-scsi@ratatosk.yggdrasil.com
From: dwarren@alpha.netusa.net (Douglas Warren)
Date: 3 Dec 1996 14:39:01 GMT
: I have been asked to set up the be-all end-all news server. A rather
: difficult request, but the SCSI subsystem I was thinking of putting in
: involved a veryfast 1GB Seagate root/swap disk and 3x 4GB Barracuda news
: disks, MDed together on two BusLogic 958 controllers, stuffed into a dual
: P200 box.
I don't say that we have the be-all end-all news server, but I rather like
the one that we did setup (When it works properly) One comment I do
have to make though is if you can afford it, add 1 or 2 more 2 gig
drives to the mixture as above, 1 For history/active, 1 for over.view
If nothing else you may find that having overview, and history on a 1
gb root is a bit of a bad thing. But this is a News issue, not a SCSI
issue =)
: I would appreciate any feedback anyone, especially Leonard, can provide
: about the possible caveats:
: - MD has in the past been unstable with SMP; is anyone running SMP MD
: news servers?
I still wonder is MD completely stable, every 14 or so days I get a
kernel panic whichI am not convinced is anything other then MD
going DOH!
: - Are 958 controllers bus-mastering? Will they play well together in the
: same machine?
Deffinitly, we run two in our news server
: - Will MD work across two controllers / a FlashPoint DW?
It'll work across 2 controllers, but I've never used a FlashPoint
so can't comment on that...
: And now some generic SCSI questions...
: If one is going to put two or more reasonably fast 4GB drives on one
: chain, is F/W SCSI II enough to keep them both hauling data at peak
: efficiency, or is Ultra Wide SCSI necessary?
F/W SCSI II should handle the load. The important issue though with
news is the number of drives that is in the spool
: Pursuing this further, would an appropriate architecture be one or two
: controllers using Ultra Wide disks, or say three/four controllers using
: Fast SCSI II disks, with the cheaper disks offset by the cost of more
: controllers and more complex cabling?
Hmmm.... That's a good issue, our current hardware is a mix of the
two. But with large numberof slower drives you divide up the time
across the RAID0... I'd say it's a tossup and depends on much much
more specifics then you've gotten into... (IE: Price, preformance
history of the drives)
: Also, in the experience of more-experienced news admins than any of us,
: are multiple smaller drives better, WRT seek time, or should one purchase
: fewer larger drives? As news is far from mission-critical, excessive
: reliability is not a particular concern.
Fewer larger drives are deffinitly not the best option the more drives
you have the faster the operation can complete, however there is the
speed/cost effective issue. With a news server though, the amount
of memory in the system is JUST as important or more so then the
hard drives... Ask the ppl down at CAIS I believe they have 3 news
servers each running 384 Megs (Not linux so not relevant to this
discussion) A good news server is possible to do under Linux, heck
feeder.erols.com is a Linux box and I believe is ranked #5 on the
Freenix top 1000 sites. (Erols cheats slightly but that's besides
the point)
---
|Douglas ``Wildcat'' Warren |Email: dwarren@netusa.net| Jura gur tbireazrag
|Network/Security Consultant|Phone: (516) 543-0234 | bhgynjf Pelcgbtencul,
|President of SBCS a chapter| Fax: (516) 543-0274 | bayl pevzvanyf jvyy
|of the ACM. | PGP: finger dwarren | unir cevinpl
