Linux-Networking Digest #505, Volume #12 Tue, 7 Sep 99 23:14:23 EDT
Contents:
Re: One Solution ISP Task: Windows NT or Linux? (Lucius Chiaraviglio)
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From: [EMAIL PROTECTED] (Lucius Chiaraviglio)
Subject: Re: One Solution ISP Task: Windows NT or Linux?
Reply-To: [EMAIL PROTECTED]
Date: Wed, 08 Sep 1999 01:45:33 GMT
Dominik <[EMAIL PROTECTED]> wrote:
>Say an ISP is looking for a one-computer solution. The computer will handle
>Main website, user websites, DNS server, mail server (no newsgroups), and
>FTP server for users only --- no anonymous.
Since you have specified hardware, I am assuming that you
already have an existing computer that you would like to put to this
task, so what I am about to say might not be helpful to you. On the
other hand, if you are still considering whether to buy the following
hardware, what I am about to say might in fact be useful.
Where I work we have Cobalt Qube 2's (one at each of 2
offices). The Cobalt Qube 2 is smaller than what you specify below,
and doesn't have all of the hardware features (but the ones it doesn't
have you probably don't need). On the other hand, unless you are
getting a really good deal on the PC, the Cobalt Qube 2 will probably
cost less, be easier to administer, and do EXACTLY what you are
specifying unless you want multihosting, in which case the Cobalt RaQ
2 would fit your bill (and only cost a little bit more than the Qube
2, but likely still less than the PC you are specifying). We don't
have a Cobalt RaQ 2, but the review of it on page 73 of the August
1999 _PC Magazine_ shows a configuration screen shot which lets me
know that I am saying the right thing, and that it can also accept
more RAM than the Cobalt Qube 2. (The Cobalt RaQ 2 is in fact
marketed for ISP's and similar enterprise server requirements.) I
posted a review of the Cobalt Qube 2 recently in this newsgroup, but
I'll try to answer your questions more specifically below.
Before I begin: I have no connection with Cobalt Networks
except as a mostly (though not perfectly) satisfied employee of a
customer and as a frequent caller to their technical support
department (they know me there now! :-P) -- certainly more satisfied
with it than with Microsoft's Windows NT 4.0. Linux gurus will be
able to point out (and I will even point out some myself) several
areas in which a full Linux installation on a PC will be more flexible
than one of the Cobalt products; on the other hand, for the
geekazoidally-challenged (that includes us), Cobalt Networks has put
together a couple of Linux-based server appliances which have a pretty
good (although not perfect) set of administration tools.
Now, on to your particulars:
>Computer specifications:
>-------------------------
>Dual Intel Pentium II 450
The Cobalt Qube 2 has a single 250 MHz MIPS (R10000?) CPU.
I'm not sure about the RaQ 2, but I think it has the same thing.
Despite having a slower CPU clock speed than several of our PC's, the
Cobalt Qube 2 performs quite well (although we haven't yet run a
severe web server performance test on our Qube 2's) -- for instance,
it can perform a diff on 2 huge (~500 Mbyte) files in 5 minutes or
less, 5 to 6 times faster than PC's with 266 MHz Pentium II or 333 MHz
AMD K6-2 CPU's can perform a Windows NT 4.0 FC on the same files.
This is probably due to differences in software efficiency (could be
in the operating system or in the particular file comparison utility;
I suspect a combination of the two) rather than the choice of CPU.
>1GB RAM
This is one parameter which will have to be smaller on the
Cobalt Networks products than what you specify. Last time I checked,
the Cobalt Qube 2 came in 3 configurations:
1. 16 Mbytes of RAM, 3.2 Gbyte IDE hard disk, cost
between $900 and $1000.
2. 32 Mbytes of RAM, 5.9 Gbyte IDE hard disk, cost
around $1200 (this is the one we have at both sites).
3. 64 Mbytes of RAM, 10.2 Gbyte IDE hard disk, cost
somewhere vaguely around $1700.
The Cobalt RaQ 2 comes in several configurations, with RAM ranging
from 16 MBytes to 256 Mbytes, and IDE hard disk ranging from 3.2
Gbytes to 16.8 Gbytes. A Cobalt RaQ 2 with 32 Mbytes of RAM, 3.2
Gbyte hard disk, two 10/100 ethernet ports, and a SCSI port costs
$1599; I do not have price information for other configurations.
>WD 18GB UW-SCSI Harddrive
If the IDE hard disk on the Cobalt products isn't large
enough, you can add a SCSI card to the Cobalt Qube 2 or get a RaQ 2
which already includes a SCSI port, and add external SCSI hard drives
(no additional hard drives will fit inside the case).
>8MB AGP Video
The Cobalt products do not have video cards. Instead, you use
your web browser to access the configuration program, or telnet in (if
you have enabled this). For initial setup (before the appliances have
an IP address), you use a console consisting of a short 2-line LCD
screen and a few buttons on the appliances; you can also use this if
you accidentally change the network settings to something that won't
let you connect with a web browser or in case you forget the admin
password (which is also the root password).
I think that this is a disadvantage relative to the Corel
NetWinder, which includes video, keyboard, and mouse ports so that you
can perform initial network configuration using decent I/O devices
when you haven't yet gotten it to exchange HTTP packets with other
computers. The Cobalt way of doing initial setup is fine if NOTHING
goes wrong, but if you have something not quite right in the
configuration of your network between the server appliance and the
client PC's, it can be a real hair-puller. The Corel NetWinder does
include video, keyboard, and mouse ports, which gives it a
considerable advantage with regard to troubleshooting initial setup --
it is apparently designed to be able to act as a Linux workstation in
addition to being a server. On the other hand, the Corel NetWinder
costs considerably more: $1839 when configured with 32 Mbytes of RAM
and a 6 GByte hard disk.
The Cobalt Qube 2 has a serial port for use with an external
modem (in case you have to use dialup access to connect to the
internet). I really wish Cobalt Networks had provided an option on
the LCD + buttons console to configure the serial port for PPP (or
even dumb terminal) login for troubleshooting the system during
initial configuration -- I suggested this to the technical support
people, but they rejected the idea.
>UW-SCSI CDROM
>12GB Tape Backup
If you have one of the Cobalt products with a SCSI port, you
can add either of these (at least I know this for the tape drive,
since I asked the Cobalt engineers about it -- I never asked them
about a CD-ROM drive).
>1.44 Floppy
This you would only be able to get by adding an external
LS-120 drive (or one of its competitors not including Zip drives) to
the SCSI chain. I never asked the Cobalt engineers about this either.
>SB 16 PNP Sound
The Cobalt products do not have this, but you do not need this
for a server. Nevertheless, at least one server appliances made by
another company -- the Corel NetWinder -- does include on-board sound
capability (and judging from the review on pages 76 - 77 of the April
6, 1999 _PC Magazine_, the sound on this unit can be pretty annoying,
too, although the review doesn't say so outright).
>Linksys 10/100 NIC
The Cobalt Qube 2 comes with 2 10/100 ethernet ports, as do
most RaQ 2 configurations.
>Server Case (6-10 Fans)
The Cobalt Qube 2 comes in a nearly cubical case which is
approximately 1 foot on each side and slightly higher; it has 1
available PCI slot (for which you need a short form-factor PCI card)
for adding SCSI cards. The Cobalt RaQ 2 comes in a 19 inch rackable
1U chassis; I have no information about availability of PCI slots in
this product.
>Network Bandwitdth:
>-------------------------
>24/7 Full T3
You will need to connect a T3-to-ethernet router (not sure
what this costs or where you get one) to the second ethernet port on
the Cobalt Qube 2 or RaQ 2.
>Should it be NT or Linux? Why?
>------------------------------
Since I am talking about Cobalt Networks server appliances, I
am talking primarily about a version of Linux (Cobalt OS 4.0 SP1)
including kernel 2.0.34. The operating system is somewhat stripped
down and does not include the sources for most things. The latter
part is somewhat bothersome to me philosophically and may seriously
upset Linux gurus, but since the appliances do most of what we need
them to do very well, and we haven't had time to complain, we don't.
(Besides, if any of us sub-geeks were actually going to do anything
with the sources, it would have to be something really simple and not
something which could affect the ability of the system to boot, serve
web pages, or serve FTP or telnet connections.) Note that altering
system files may affect your warranty -- consult with Cobalt Networks
technical support and prove a need and a good plan for doing this
before you try any such thing. Note that the same thing holds true
for Microsoft software, but most likely you will either never be able
to get that far with their technical support, or else (judging from
other people's experiences -- I never got that far myself) they will
do one or more of: instruct you to do something really hairy and
probably non-sensical, instruct you to reinstall the whole operating
system, or point a finger at some third-party software.
>Consider the following:
>
>- Ease of maintence
From what I have read, Linux has lower maintenance than
Windows NT overall, but it can be plenty hairy on the rarer occasions
that it does need maintenance, and initial setup can be painful. From
my own experience setting up 2 Cobalt Qube 2's, getting the network
connections set up initially can be excruciating (Cobalt's ease of use
efforts really fall short here), but once you get through that part,
the rest of the setup is very easy -- the web-based configuration
utility really does work well, except for having insufficient on-line
documentation about what some of the network parameters do and
insufficient diagnostics for early parts of the network setup. If you
have to telnet in and read man pages to set something up, the man
pages are of really spotty quality, but on the other hand, Microsoft's
on-line help for setting up and troubleshooting network functions
seems to be almost uniformly bad.
Note: if you get a Cobalt Qube 2 which has been sitting
around in stock for a while and thus has Cobalt OS 4.0 without SP1,
you will need to download and install SP1 (I forgot what they actually
call it) before you will be able to configure mail service correctly.
I had to do this for our first unit but not our second unit.
Another note: after making some network configuration
changes, Cobalt OS 4.0 on the Qube 2 makes you reboot (comparable to
Windows NT). I am no Linux guru, but I do know that this should not
be generally necessary for Linux. I would suspect that this is
better on the RaQ 2, which is designed to be able to do multi-hosting.
In comparison, Windows (95/98/NT 4.0) networking is often
fairly easy to set up, but it can be tooth-pulling sometimes. With
our first Cobalt Qube 2, some of the network setup problems we had
were actually incorrect configuration of the Windows networking on the
client PC's, but it was very difficult to determine that this was the
case (easy to fix once we finally figured it out).
>- Speed
See above about CPU.
>- Reliability
We have had Cobalt OS (Linux) crash one or two times while
trying to set up networking initially (and no, it wasn't just that the
web-based configuration utility didn't work any more -- the LCD +
button console froze too), but other than that, it has been very
stable.
>- GUI?
See above about ease of setup and maintenance.
>- Cost
I cannot find the price of Windows NT Server 4.0 off hand, but
I know that it already costs something in the upper hundreds of
dollars for the basic system with a 10-client license, and the cost
goes up fairly steeply with additional client licenses. Linux, of
course, has no license limit, and the Cobalt Qube 2 (and I assume also
the RaQ 2) has no client license limit, although you will eventually
run into practical limits on the number of simultaneous clients
(according to Cobalt Networks technical support, this could be in the
hundreds of clients for a medium-configured Qube 2; I did not ask
about the RaQ 2 practical client limit).
>- Heat
The Cobalt Qube 2 seems to generate very little heat. No heat
sink is visible on the system boards.
>- Support
The Cobalt Networks technical support people can be a little
hard to get a hold of, but they will spend the time to try to figure
out your problem (although they will not always succeed). For normal
distributions of Linux, I cannot comment much except to say that while
people post considerable complaints about the technical support (or
lack thereof) provided by the commercial distribution manufacturers,
the support available on the internet newsgroups seems to be usually
pretty good. Microsoft technical support, on the other hand, is a
real challenge to get any help from without paying something on the
order of $30 per incident, although I did succeed once in this
endeavor by using their web technical support service.
>- Ease of installation
See above about ease of setup and maintenance.
>- Compatibility
My ability to comment on this is spotty. I know that the
Cobalt products include CGI support, but I have never tested it. A
few third-party applications are available for Cobalt Qube 2's (and
presumably RaQ 2's, but I haven't looked), but installing them on
your unit may affect your warranty. I think that I saw a C compiler
on our Cobalt Qube 2, but I wouldn't swear to it while I am not
connected to it. The Cobalt products include Legato backup for
backing up user files to a client PC, but I don't know if this works
for backing up files to a directly-attached SCSI device.
As for compatibility of the services, the compatibility of
your web pages on the Qube with various browsers is up to you; the
Cobalt Qube 2 offers Microsoft FrontPage Extensions, but we haven't
tried them, and leave this feature turned off. The Cobalt Qube 2
management web pages seem to work more smoothly with Microsoft
Internet Explorer 4.0 SP1 than with NetScape Communicator 4.5.1/4.6.1
for Windows 95/98/NT (haven't yet tried NetScape for other platforms),
but they function fully with both web browsers, assuming your web
browser doesn't crash or freeze while using them. NetScape Navigator
4.0.x and NetScape Communicator 4.5.1 would sometimes crash or freeze
while using the Cobalt Qube 2 web-based configuration utility; I have
tested NetScape Communicator 4.6.1 with these pages and it hasn't yet
had a crash attributable to these pages (but NetScape Communicator
4.6.1 tends to crash randomly anyway :-b), but I haven't tested it for
very long, and I now use Microsoft Internet Explorer 4.01 SP1 for this
purpose unless I am administering a Qube 2 from a computer that
doesn't have Microsoft Internet Explorer 4.01 SP1. Microsoft Internet
Explorer 3.02 doesn't seem to work with the Cobalt Qube 2 management
pages; I haven't tried versions of NetScape Navigator older than
4.0.5. Note: you have to have JavaScript enabled to use the Cobalt
Qube 2 management pages (they won't even display correctly without
it), so you won't be able to administer a Cobalt Networks server
appliance if your browser doesn't support JavaScript or if its
JavaScript implementation is broken (as Microsoft Internet Explorer
3.0x's seems to be).
The Cobalt OS 4.0 SP1 (see above note about the need to update
Cobalt OS 4.0 to 4.0 SP1) POP3, IMAP4, and SMTP mail services have
shown no compatibility problems with NetScape Messenger 4.5.1/4.6.1 or
Eudora Pro 4.1 (only tested POP3 and SMTP); I think some of our people
are using Microsoft Outlook and/or Outlook Express (version(s)
provided with Internet Explorer 4.0 and/or 5.0) as mail clients, but
I'm not sure (and I haven't heard any complaints). I have had some
compatibility problems of Windows telnet with Cobalt OS's
interpretation of what kind of terminal the telnet session is
emulating (noted when using vi and less), but this is attributable to
bugs in Windows telnet's ANSI terminal emulation (in general, Windows
95/98/NT 4.0 telnet really leaves something to be desired) -- the
Cobalt OS less utility works fine with some other telnet program
(unfortunately I forgot which one). The Cobalt OS FTP server (ProFTP,
forgot which version) works flawlessly with both the FTP client
programs of both Cobalt OS 4.0 and Windows 95/NT 4.0. The Cobalt OS
DNS server seems to work just fine. The Cobalt Qube 2 DHCP server
seems to work just fine except that we have 2 laptops running Windows
95 which insist on setting themselves to the same address as the
Qube's internal network address if they are set to use DHCP, so we
just set them to high-numbered static IP addresses on our internal
networks. The Cobalt Qube 2 Windows File Sharing service (Samba
1.9.something) seems to work properly except for a bug which can
cause the Samba password not to be updated when you change your
general password -- this took us a long time to figure out, and had
Cobalt Networks technical support stumped. We did have a problem
which caused our Windows NT 4.0 SP3 file server to quit working until
we put it and the Cobalt Qube 2 in different Windows NT domains.
Note: as far as I know, the Cobalt RaQ 2 does not offer DHCP service
or Windows File Sharing. Cobalt OS 4.0 has a SNMP agent, but we
haven't tested it. The Cobalt Qube 2's Network Address Translation
seems to work with everything we have tried except for video-
conferencing programs (Microsoft NetMeeting 2.1/2.1.1/3.0 beta and
White Pine CU-SeeMe Pro 4.0), which White Pine Software says won't
work with any NAT service. I do not know whether the Cobalt RaQ 2
offers NAT service, but given that you can order it configured with 2
ethernet ports, it should.
Normal Linux distributions should provide the above services
just as well as one of the Cobalt Networks server appliances, and you
would have the opportunity to upgrade to later versions of some of
them (for instance, Samba 2.0.5b). They would also be more flexible,
but harder for sub-geeks (like us) to configure.
From what I have seen and dealt with, Windows NT 4.0 services
can be reasonably easy to configure, but they can also be hair-
pulling. Microsoft network services are generally compatible with
other Microsoft stuff, but judging by how compatible various parts of
Microsoft system software and applications are with each other and
themselves, this is not guaranteed unless Microsoft has done a much
better job of implementing the network services and client programs
than, for instance, it has implemented OLE between various parts of
Microsoft Office 95/97 (and more particularly, better than it has
implemented terminal emulation in its telnet client).
>- Down-time situation
Once we got through initial configuration, we haven't had any
downtime with the Cobalt Qube 2's. Windows NT Server 4.0 (SP1 and
SP3) has proven to be somewhat flaky, but crashes are at fairly long
intervals. I haven't tried an installation of normal Linux as a
server yet, but from what I read on here, it is usually better than
Windows NT 4.0, but still has the potential to be flaky if
misconfigured or running on flaky or poorly-supported hardware. (The
same is true of Windows NT, so what I just said isn't particularly
useful.)
One area in which the Cobalt Networks products fall short is
the ability to recover from a disaster which renders the system
unbootable or unable to communicate with web, telnet, and/or FTP
clients. With a normal Linux distribution on normal hardware or with
Windows NT, you can reinstall the operating system and everything else
if you have to, but with the Cobalt Networks server appliances, if
things get this bad, you have to send them in for service. It should
be theoretically possible to pull the hard disk out of a fried server
appliance, put it into a Linux computer, and fix it, but if you have
to rewrite something that the boot-loader needs to find to boot (the
kernel, etc.) the operating system, you might be in trouble. I
haven't asked Cobalt Networks technical support about whether one
could do this.
Therefore, if you are going to use a Cobalt Networks server
appliance for something which demands no interruptions in
availability, I would recommend getting two of them, so that one can
take over in case the other one fries. You might even be able to use
the hard disk for one of them as a template from which to restore the
other, but see the above warning about things that the boot loader
might need to find and be unable to do so after a rewrite.
>This is a real situation. Any response will be appreciated. Thank you.
I don't know enough about your real situation to say which
operating system or hardware will be better for you, but if you are a
sub-geek and can live with the configurability and recoverability
limitations noted above, check out the Cobalt Networks products (if
you don't need to run an application on the server which rules them
out). Since you did not specify RAID or other fault-tolerant
components (apart from extra fans) in your server PC configuration,
and did not specify a need to run specialized server applications, I
think that the Cobalt Networks server appliances might fit your bill.
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