Linux-Hardware Digest #208, Volume #13 Mon, 10 Jul 00 14:13:08 EDT
Contents:
Re: optimize scsi hard drives (Johan Kullstam)
Re: optimize scsi hard drives (Duane)
Re: Weird corruption problems (Ross Vandegrift)
keyboard with additional function keys ("LY")
Re: NO DIALTONE message with my modem
Unix Linux Clustering (Varma)
Re: equipment for multi-DSL conections? (Brian Stretch)
Re: mother board recommendations for an 800MHz system (Kenaniah)
Re: mother board recommendations for an 800MHz system (Brian Stretch)
Clustering on Multiple platforms. (Varma)
Re: equipment for multi-DSL conections? (Mark Astley)
Re: Linux home server: Clean-slate hardware plan? (David C.)
----------------------------------------------------------------------------
From: Johan Kullstam <[EMAIL PROTECTED]>
Subject: Re: optimize scsi hard drives
Date: 10 Jul 2000 13:00:28 -0400
"Reed Gregory" <[EMAIL PROTECTED]> writes:
> Ok, i know how to optimize my ide hard drives with hdparm but do not know
> how to optimize my scsi drives to get them to perform at their best.
you don't need to do it as the scsi hardware is smarter than the eide stuff.
> i have a adaptec 2940UW card with a WD Enterprise 7200rpm UW drive.
> when i do a /usr/sbin/hdparm -Tt /dev/sda it gives a result of 4
> MB/s when the interface should be 40! Any help would be
> appreciated.
1) WD used to make one of the slowest SCSI drives around. they got
clobbered in the market and pulled out of SCSI. 4MB/sec does seem
a bit weak. as a point of reference, my ibm and fujitsu 7200 rpm
drives get about 6-8MB/sec according to hdparm.
2) the *interface* is capable of 40MB/sec (less some overhead of about
10%). however, the *disk* is not. no single disk can do more than
about 30MB/sec, 160MB/sec U3W or ATA100 notwithstanding. since you
can put multiple disks on one SCSI bus, you really want the
inteface to be much faster than the disk.
--
johan kullstam l72t00052
------------------------------
From: Duane <[EMAIL PROTECTED]>
Subject: Re: optimize scsi hard drives
Date: Mon, 10 Jul 2000 09:29:10 -0700
Reed Gregory wrote:
>
> Ok, i know how to optimize my ide hard drives with hdparm but do not know
> how to optimize my scsi drives to get them to perform at their best. i have
> a adaptec 2940UW card with a WD Enterprise 7200rpm UW drive. when i do a
> /usr/sbin/hdparm -Tt /dev/sda it gives a result of 4 MB/s when the interface
> should be 40! Any help would be appreciated.
>
> Thanks
> Reed
I would not completely trust hdparm for benchmarking drives. There is no
DMA enable for SCSI like there is for IDE drives (SCSI is pretty much
always running DMA mode).
Also, while your SCSI interface may be capable of 40MB/sec, your disk
certainly is not capable of sustained transfers at that rate. Depending
on exactly which disk you have, it might be below 8MB/sec. The biggest
advantage of Ultra wide SCSI is if you are running a disk array.
While there are various opinions on the subject, I have a hard time
justifying the huge markup currently being charged for SCSI if you are
running one or two disks on a desktop computer.
--
My real email is akamail.com@dclark (or something like that).
------------------------------
From: Ross Vandegrift <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.networking
Subject: Re: Weird corruption problems
Date: Mon, 10 Jul 2000 13:16:44 -0400
Reply-To: [EMAIL PROTECTED]
> I'm shooting at the power or lack thereof. Get a UPS NOW!! That will at
> least prevent future power problems from affecting you. Since you have a T1,
> I'm assuming you can afford to purchase a UPS, I think you can get them for
> less than $100 now.
The machine is on a very nice UPS. It provides conditioned power, has
batteries less than a year old, and has been tested to be in tip-top
shape. Maybe it's not the power? Do you still think it might be the
power supply gone bad?
> You've seen data corruption on both / and the raid. What level of raid? I'm
> assuming one. You'll have to weigh the time vs. money factors but I think I'd
> start with a new motherboard and perform the non destructive disk tests. If
> you still see problems then examine disk cables, power supply. You might want
> to replace the power supply along with the motherboard. If the power supply
> is in fact bad, it might damage the new motherboard.
We've had a lot of problems with WD disks in this machine before, but it
turned out that a batch of 13G's that we ordered had been damaged in
shipping. Once we got new disks into the machine, they've been working
wonderfully. Being paranoid about them going bad too, we've tested those
disks fairly seriously, and I'm willing to confidently say they would pass
the WD scan. The motherboard and power supply could still be issues, but
the boss isn't going to like that one... it's a co-located machine at a
local ISP.
In addition, he is convinced that the ext2 filesystem is at
fault (he hasn't looked at it or anything, he just knows ::-). Is there
any logic that something weird could be happeneing on the filesystem layer
that is causing this??
Thanks,
Ross Vandegrift
------------------------------
From: "LY" <[EMAIL PROTECTED]>
Crossposted-To:
comp.os.linux.development.apps,comp.os.linux.development,comp.os.linux.development.system
Subject: keyboard with additional function keys
Date: Mon, 10 Jul 2000 19:12:35 +0200
Hi!
Can someone help me!
I have a keyboard with about 30 additional function keys. If I press one key
it gives me for example a double "4" or "a" ... (44, aa, ...). It means that
I get double scancodes. These parts of this sequence of scancodes are the
same and they are known.
Do someone know how to change this sequence of double scancodes in a unique
scancode? Or can somebody write a program for solving this problem?
If someone can really solve this problem, then please contact me!!! I would
give a little pocket money (allowance)!
Sincerely,
LY
------------------------------
From: <[EMAIL PROTECTED]>
Subject: Re: NO DIALTONE message with my modem
Date: Mon, 10 Jul 2000 17:30:06 GMT
elwood wrote:
>
>
> Hi Linux people,
> I'm trying to connect to my ISP with Linux, but I got the message NO
> DIALTONE immediatly. If I remember correctly I'd the same problem
> configuring it on Win95 (lot time ago) and I solved the problem setting
the
> modem in way it didn't wait for the dial tone. It can be the same
problem?
> If yes, how I can make the same with Linux.
> My modem is based on the Rockwell RCV336ACF chipset and it is an ISA
modem
> with jumper for I/O and IRQ.
>
> Thanks a lot to all the Linux guys
> Elwood
>
>
--
Posted via CNET Help.com
http://www.help.com/
------------------------------
From: Varma <[EMAIL PROTECTED]>
Subject: Unix Linux Clustering
Date: Mon, 10 Jul 2000 10:22:47 -0700
Does anyboy used Enfuzion, which ebables clustering on multiple
platforms? or does anybody know a better way or a better product for
clustering in multiple platforms like Unix,Linux, Windows NT??
* Sent from RemarQ http://www.remarq.com The Internet's Discussion Network *
The fastest and easiest way to search and participate in Usenet - Free!
------------------------------
From: Brian Stretch <[EMAIL PROTECTED]>
Subject: Re: equipment for multi-DSL conections?
Date: Mon, 10 Jul 2000 17:41:44 GMT
It's not a dumb switch. Hit the buy.com link. The box is a switch and
does firewall/NAT, just plug it in and go. If you have a DSL or cable
modem and don't want to set up a proper Linux server, this is without a
doubt the way to go.
Harry Styron wrote:
>
> Hi Chris:
>
> You can't just put a dumb switch or bridge between you and your ISP, and then
> put more than one computer on the other end. Each computer requires its own IP
> address. You can do this with a masquerading firewall on Linux, or you can get
> multiple IP addresses from your ISP (and probably pay for the privilege).
>
> Harry Styron <[EMAIL PROTECTED]>
>
> Chris Harshman wrote:
>
> > I can vouch for the Linksys device. Worthy of note:
> > - It's a 4-port 100/100 SWITCH, not just a hub.
> > - It can do port forwarding, so port 80 on the firewall (the DSL IP address)
> > can point to port 80 on your Linux box, allowing you to serve from behind
> > the firewall.
> > - You can set up a DMZ host that has unfettered access to the 'net, and
> > vice-versa.
> > - It supports PPPoE (necessary for running over my el-cheapo PacBell feed;
> > dynamic IPs suck)
> >
> > I've had one in place for about a month, and couldn't be happier. I'm
> > running Firmware 1.22, which had to be downloaded from the website and
> > installed, no big deal.
> >
> > > If you want to keep it simple and not dedicate a full-blown machine, buy
> > > one of these:
> > >
> > > http://www.us.buy.com/comp/product.asp?Sku=10235958
> > >
> > > A friend of mine bought one on my recommendation and has been very
> > > pleased with it. Basically a 4-port hub that does NAT/firewall and all
> > > that good stuff. Just plug it in and go. Got a good mention on
> > > http://www.grc.com too (Shields UP! site, quick test of network
> > > security, lots of neat info).
--
Brian Stretch http://www.mindspring.com/~bstretch Cert. Technojunkie
"Wherever there is a jackboot stomping on a human face there will be a
well-heeled Western liberal to explain that the face does, after all,
enjoy free health care and 100 percent literacy."--John Derbyshire, NR
------------------------------
From: Kenaniah <[EMAIL PROTECTED]>
Subject: Re: mother board recommendations for an 800MHz system
Date: Mon, 10 Jul 2000 13:41:35 -0400
Supermicro supports linux well. I have had no trouble using these boards. Rock Solid!
They have some boards that will support up to 933's.
Mark
[EMAIL PROTECTED] wrote:
> I am looking to build a new system, and I have gotten hung up on picking a
>motherboard. Any suggestions for a mobo running a singe PIII 800MHz? Chipset? I am
>looking for something that will be upwardly compatible with faster CPUs. I have
>looked at Abit, Asus, and SuperMicro boards and cannot decide.
>
> Anthony
------------------------------
From: Brian Stretch <[EMAIL PROTECTED]>
Subject: Re: mother board recommendations for an 800MHz system
Date: Mon, 10 Jul 2000 17:50:41 GMT
FCPGA or Slot 1? If you haven't bought the chip yet, may I suggest
buying a 900MHz Thunderbird-core Athlon instead? (http://www.mwave.com
claims to have them in stock, I bought other hardware from them recently
without incident.) That and a MSI Socket A motherboard, the ASUS boards
aren't in yet.
But if you've truly settled on the P3-800, I'd wait a short while for
the ASUS CUSL2 motherboards to show up on the market. Intel 815
chipset, does PC133 SDRAM, getting great reviews. Or if you're going to
run 100MHz bus anyhow or don't mind massively overclocking your AGP bus,
get the ASUS CUBX. (These are both Socket370 FCPGA boards.) I recently
bought the CUBX (didn't know about the CUSL2's impending arrival) for my
new Linux server and I'm happy with it. As a rule I buy ASUS
motherboards. Chip Merchant (http://www.thechipmerchant.com) has CUBX
motherboards in stock, MWave doesn't. Given the relatively low cost of
motherboards, I wouldn't worry too much about upward compatibility,
you'll probably want to get a new board with a new CPU anyhow. Tends to
work that way for me :-).
[EMAIL PROTECTED] wrote:
>
> I am looking to build a new system, and I have gotten hung up on picking a
>motherboard. Any suggestions for a mobo running a singe PIII 800MHz? Chipset? I am
>looking for something that will be upwardly compatible with faster CPUs. I have
>looked at Abit, Asus, and SuperMicro boards and cannot decide.
--
Brian Stretch http://www.mindspring.com/~bstretch Cert. Technojunkie
"Wherever there is a jackboot stomping on a human face there will be a
well-heeled Western liberal to explain that the face does, after all,
enjoy free health care and 100 percent literacy."--John Derbyshire, NR
------------------------------
From: Varma <[EMAIL PROTECTED]>
Subject: Clustering on Multiple platforms.
Date: Mon, 10 Jul 2000 10:35:54 -0700
Does anyboy used Enfuzion, which ebables clustering on multiple
platforms? or does anybody know a better way or a better product for
clustering in multiple platforms like Unix,Linux, Windows NT??
We have 4 Unix AIX 4.2 Servers and 5 VA linux servers. Our parent
processes will genetate many child processes and use to run for hours.
What we are trying to achieve is to submit the parent process in the
Unix machine,distribute thsese child processes to Linux machines and
get the result back to the Unix machine.
Enfuzion is a product (Turbo-Linux) which allows this kind of
clustering. It works without dedicated servers or workstations and
integrates transparently into your current Linux, UNIX and Windows NT
environment. But it's expensive.
So, if anybody has a better idea or knows about a better(and cheeper)
product, please let us know.
Thanks
Has anybody tried this before?
* Sent from RemarQ http://www.remarq.com The Internet's Discussion Network *
The fastest and easiest way to search and participate in Usenet - Free!
------------------------------
From: Mark Astley <[EMAIL PROTECTED]>
Subject: Re: equipment for multi-DSL conections?
Date: 10 Jul 2000 13:46:20 -0400
The device Chris is referring to isn't just a dumb switch. It's
basically a firewall built into a switch. Not a flame, but you should
read the docs next time. This is a great solution for those of us
with multiple machines but only one IP to share.
mark
Harry Styron <[EMAIL PROTECTED]> writes:
> Hi Chris:
>
> You can't just put a dumb switch or bridge between you and your ISP, and then
> put more than one computer on the other end. Each computer requires its own IP
> address. You can do this with a masquerading firewall on Linux, or you can get
> multiple IP addresses from your ISP (and probably pay for the privilege).
>
> Harry Styron <[EMAIL PROTECTED]>
>
> Chris Harshman wrote:
>
> > I can vouch for the Linksys device. Worthy of note:
> > - It's a 4-port 100/100 SWITCH, not just a hub.
> > - It can do port forwarding, so port 80 on the firewall (the DSL IP address)
> > can point to port 80 on your Linux box, allowing you to serve from behind
> > the firewall.
> > - You can set up a DMZ host that has unfettered access to the 'net, and
> > vice-versa.
> > - It supports PPPoE (necessary for running over my el-cheapo PacBell feed;
> > dynamic IPs suck)
> >
> > I've had one in place for about a month, and couldn't be happier. I'm
> > running Firmware 1.22, which had to be downloaded from the website and
> > installed, no big deal.
> >
> > > If you want to keep it simple and not dedicate a full-blown machine, buy
> > > one of these:
> > >
> > > http://www.us.buy.com/comp/product.asp?Sku=10235958
> > >
> > > A friend of mine bought one on my recommendation and has been very
> > > pleased with it. Basically a 4-port hub that does NAT/firewall and all
> > > that good stuff. Just plug it in and go. Got a good mention on
> > > http://www.grc.com too (Shields UP! site, quick test of network
> > > security, lots of neat info).
> > >
------------------------------
From: [EMAIL PROTECTED] (David C.)
Subject: Re: Linux home server: Clean-slate hardware plan?
Date: 10 Jul 2000 13:55:27 -0400
"Steve Conover, Sr." <[EMAIL PROTECTED]> writes:
>
> Hello Linux experts. I'm a novice who wants to network my home, but
> wants to avoid purchasing NT Server, for lots of reasons.
>
> My goal: Linux home server for three or four PC's, for sharing files,
> printers, and cable modem internet connection.
What kind of clients are you going to be running?
If they are all Windows clients, you're going to need to set up and
configure Samba on the server. This isn't hard, but you may find a bit
of a learning curve involved.
I would recommend two computers here. One to act as your file/print
server, and another to act as a firewall/router (for sharing the
internet connection). I recommend not running any applications or
servers on the firewall computer.
Fortunately, the firewall computer can be really cheap. Cable modems
are fast compared to modems, but they're slow compared to Ethernet. A
486 with two 10M ethernet cards will work fine in this capacity. In
case you're curious, here's what my firewall has:
- Generic "Deep Green" 486 motherboard with AMD 120MHz CPU.
(8 ISA slots, 3 with VLB extensions. No on-board devices.)
- 40M RAM
- Generic VLB controller for serial, parallel and single-channel IDE
- Generic VLB S3 805-series video
- 1G WD Caviar IDE hard drive
- Generic (Nucom) IDE CD-ROM drive
- E-Link 16 (NE-2000 clone) 10M Ethernet card
- 3Com Etherlink II/16 10M Ethernet card
- Generic keyboard
- No mouse
Yes, this is a slow system.
Yes, I have two devices on a single IDE channel, but it doesn't matter
because I almost never use the CD-ROM.
Yes, the bus is ISA, and these are 10M cards, but it doesn't matter
because the DSL line has a top speed of 270Kbps anyway.
> Group 1: planned hardware I don't own yet:
>
> Motherboard: ASUS P2B w/ onboard Adaptec SCSI controller
It will work, but you probably won't require the SCSI interface unless
you are going to run multiple drives, or if you run software on the
server itself. A light-duty file server will probably not generate
enough load on its own.
You should compare the difference in price between the board with SCSI
and the one without. Even though you already have an Ultra2 SCSI hard
drive, keep in mind that you can get a 10G IDE drive for less than $100
- which is probably less than the amount you'll save on the motherboard.
Still, if you want to spend the money on the motherboard, I think you'll
be satisfied with it.
> CPU: Intel P-III ~500MHz
Any CPU will be fine for routing packets to your cable modem. IMO,
anything 400MHz or faster should be fine for file and printer sharing,
since those tasks will be I/O bound anyway.
If you plan on running apps on the server, then the faster CPU may be
useful.
> NIC: 3COM 10/100
3Com makes a lot of different models. I assume you're talking about the
3c905 series. I have used them (905, 905B and 905C) without problem.
Keep in mind that some older kernels don't support the 905C. If you use
a current release (kernel 2.2.x or later), you shouldn't have a problem.
Keep in mind also, that there are other good (and less expensive) NICs
out there.
Also keep in mind that 10M may be good enough. Especially if most of
your network traffic is going to be funneled to the internet via your
cable modem anyway.
> Cable, RJ-45 twisted pair (specs?)
Anything Cat-5 rated should be fine. Just make sure you don't confuse
straight cables with crossover cables. A straight cable has all the
wires connected in the same order on each end. A crossover cable swaps
wire pairs 2 and 3. If the cable isn't labeled, you can tell by looking
through the plastic connectors at the ends.
In general, you want to use a straight cable to connect a host
(computer, printer, whatever) to a hub. You want to use a crossover
cable to connect a device to another device, or to attach a hub to
another hub. (The exception here being that some hubs have an "uplink"
port - in which case, you can use a straight cable to connect two hubs.)
> Graphics card: ? (suggestions please)
For a server? It doesn't matter. A GUI just consumes CPU cycles which
are better used for the server programs. Don't even bother launching
the GUI - just let the server run in text mode. Get the cheapest video
card you can find. A motherboard with on-board video is also OK for
this application.
Also note that a high-end video card will probably consume more power
and generate more heat than a cheapo card.
> SCSI CD-ROM drive: ? (suggestions please)
Your CD-ROM drive is not going to get much use. You're probably going
to use it to install (and later upgrade) Linux itself, and maybe to
install a software package or two. But you're not going to be using it
for anything else. After all, this is a server, not a workstation.
Get the cheapest CD-ROM you can find. This probably means IDE. Don't
worry about it sharing an IDE channel with a hard drive. The CD-ROM
drive will be sitting idle most of the time, so it won't interfere with
the hard drive's performance.
> Group 2: hardware I already own:
>
> Hard drive: Seagate Barracuda, Ultra-2 SCSI, 9G
A nice drive. But it does require you to have a SCSI controller, which
may cost more than a new hard drive.
> Monitor: ViewSonic 17"
Nice, but wasted for a server. Since the server will usually be in
text-mode, and with the monitor turned off, you're better off using that
17" monitor on a workstation. Get a cheap 15" monitor for the server
console. (I've seen used ones in good condition for $60 at local flea
markets.)
You can also choose to run the server with no monitor. Install
everything using the 17" monitor you've got, and then disconnect it when
you're done. When you need to administer the server, you'll just log-in
over the LAN.
> Printer1: LaserJet 5
> Printer2: Phaser 740
Very nice. Linux shouldn't have any problem serving them. Note that
your server will need enough interfaces for them. You may need a second
parallel port, unless one of them has a serial (or Ethernet) interface.
> Logitech keyboard, trackball
Don't worry about this.
Since you won't be logged in at the console very much, any cheap
keyboard will suffice.
Since you won't be running a GUI, you can eliminate the trackball (or
other pointing device) as well.
> ...oh yeah; I also own:
> screwdriver; pliers; fire extinguisher; sledgehammer :-)
Some useful tools, if you don't already have them include:
- Socket wrench set with a 1/4" spinner. A small set isn't very
expensive. I find that the hex-screws are easier to install/remove
with a socket and spinner than with a screwdriver. Loosen really
tight ones with the ratchet. (Don't tighten with the ratchet, however
- it's too easy to overtighten a screw and damage something.)
- Ground strap. I always like to be grounded when working with
static-sensitive parts, like motherboards and RAM. I'm less careful
when working with parts that have no exposed circuit boards (like
CD-ROM drives and some hard drives.)
- Thermal compound. aka. thermal grease. Be sure to apply some between
the CPU and its heat-sink/fan. Thermal compound helps the heat sink
absorb heat from the CPU. There can be a 10 degree difference in CPU
temperature between using it and not using it.
- You didn't mention what kind of case you've got. If you have a 7200
RPM (or 10,000 RPM) hard drive, or if you have more than one hard
drive, cooling may be a problem. If you're not sure about your case's
cooling capability, consider adding some extra fans. Most minitower
cases sold these days have room to attach one or two fans (in addition
to the one in your power supply and the one(s) on your CPU.) If you
add extra fans. be sure to get the airflow direction correct. You
want as much air as possible flowing through the case.
> I would appreciate watch-outs, suggestions, and warnings. Also,
> advice on anything I might have overlooked. Thanks a lot.
You only mentioned one Ethernet card. A server on a LAN only needs one,
but a box that's going to be a gateway between a LAN and the internet
will need two.
-- David
------------------------------
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