Date: Tue, 5 Nov 1996 17:07:21 -0800 (PST) From: Veggy Vinny <richardc@CSUA.Berkeley.EDU> To: Joe Greco <jgreco@brasil.moneng.mei.com> Cc: michaelv@MindBender.serv.net, mark@quickweb.com, terry@lambert.org, imp@village.org, jmb@freefall.freebsd.org, isp@freebsd.org, chad@gaianet.net, mario1@PrimeNet.Com, johnnyu@accessus.net Subject: Re: /usr/obj size Message-ID: <Pine.PTX.3.95.961105170046.4315j-100000@soda.CSUA.Berkeley.EDU> In-Reply-To: <199611060030.SAA07510@brasil.moneng.mei.com>
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On Tue, 5 Nov 1996, Joe Greco wrote: > > > Vince, > > > > > > IMHO it depends on what you are going to do with the machine. Are you going > > > to have lots of readers? Lots of inbound and/or outbound feeds? (Remember > > > that many sites these days feed via "innfeed", and this counts as multiple > > > feeds)... > > > > All the users will be using nntp from within GAIANET.NET. We will > > have a newsfeed from Concentric Network but will probably have some feeds > > to others. > > How MANY users? If you have no idea, project 1/10 of your number of > modems. That is an almost useless guess, but it is at least probably > going to be the right order of magnitude. Well, don't know the exact amount of users since some come in by telnet and others come in by the 4 dialup modems... > > > If you are going to have one user reading news and have a single inbound > > > feed, sorted, held for half a week, and nothing else, you might be able to > > > do it on a fairly skimpy system. > > > > > > My idea of fairly skimpy would be 486DX/133, 64MB RAM (maybe 48MB), a fast > > > disk for root/var/newslib, and a big disk for spool. You might be able to > > > get away with less memory by using C-News. > > > > We'll have this as the minimum of a sysem. Dual PentiumPro-200Mhz > > with 128MB of ram and a Seagate Elite 9 9.1 gig Fast Wide SCSI-2 drive to > > start with. > > Dump the Dual, dump the Pentium Pro. You are not doing raytracing, you > are providing news service. For this kind of application you need to be > able to move data quickly. So the Dual and Pentium Pro won't do much good? > Get a P133 on a good Triton-II board. Okay... > Use the money you save to buy more disks. With PP200's going for over $1000 > each, you should be able to get half a dozen 1G disks with the savings. Yep, good point. > (You do NOT want to use the Elite on a machine with multiple news feeds. > You do NOT want to use the Elite on an ISP class news server. It will > melt. No way in hell can it handle the number of transactions per second > required!) We already have the Elite so that can't be replaced :-) > Get more RAM. How much RAM do we need exactly? > Then get more CPU. In that order! :-) Okay :-) > > > My standard cuff calculation formula for RAM is: > > > > > > 1MB * active readers + 2MB * number of feeds + 8MB for system + 2 * > > > sizeof(history.pag) > > > > > > I consider this to be a minimum. News will make very good use of as > > > much memory as you can give it. One of my clients considered it to be > > > an excessive maximum and learned a very expensive lesson when their > > > news service sucked. > > > > Hmmm, when you mean by active readers, you are talking about the > > amount of nntp clients accessing the newsserver at once? > > Yes. "active" refers to any client that has not been sleeping for 15 > minutes... you get some of those too and it is OK to let them swap out. Oh I see. > > > For a CPU, I have not found a significant need to go beyond a P133. > > > 'newspump.sol.net' is a P133, and is a dedicated feeds machine. It > > > ranks #25 in the Freenix ratings this month. A large client has 100-150 > > > nnrp sessions reading news on their P133 boxes, with CPU to spare. This > > > game isn't really about CPU, it is more about memory, caching, and I/O. > > > Besides, CPU is cheap. > > > > Hmmm, okay.... Do you or anyone know how well a FreeBSD machine > > would compare to a SUN? I was saying that the FreeBSD machine can easily > > do better than the SUN's since I can see how well wcarchive.cdrom.com is > > doing with the high loads. > > You get more bang for your buck with the PC. CPU is 1/5 the price, memory > is 1/2 the price, I/O controllers are 1/10 the price. Take the money you > save and buy disks. Good point. > I run news servers under Solaris. Spool.mu.edu is a doggy SPARCstation > 10/30 that is roughly equivalent to a P60. It is a very busy machine.. > it is a good machine... but intuitively I believe that a PC equivalent > would be faster, and absolutely cheaper. Yep, it sure seems like it from the loads a PC can handle. > > > Chipset is ultimately important. You WILL not be successful if you buy > > > a cruddy motherboard/chipset. Buy Triton-II. I recommend the ASUS > > > P/I-P55T2P4, or P/E-P55T2P4D (see http://www.asus.com.tw). I recommend > > > buying hardware from Rod Grimes, I have never been disappointed by his > > > services and support. <sales@gndrsh.aac.dev.com>. > > > > Yep, I know. I got a P55TP4XE from Rod and it's still working in > > one piece today with no problems whatsoever. Too bad mines is the > > original Triton though. Rod surely knows the part he sells and can give > > you every bit of info you want to know. > > I am using several as well. Work great, no parity, only 128MB RAM > supported, but really one of the best boards available at the time. Yep, it sure is. I wonder if the Triton II is any faster. > > > Do not compromise on your I/O system. News is extremely taxing on a > > > machine's disks. Buy multiple SCSI busses. It is much better to buy > > > three $70 ASUS SC-200 NCR-810 controllers than one $220 AHA-2940 SCSI > > > controller (but if you want to spend $660 on three AHA-2940's, that > > > is not a bad solution either). Buy lots of disks. Stripe them with CCD. > > > The reader machines noted above have 12 disks each: > > > > What about for Wide SCSI or Ultra/UltraWide SCSI drives? Which > > controllers would be good? > > To hell with Wide SCSI. > > If you are transferring 50 MB of data from a large file, you will be well > served by a pair of CCD'd drives with Wide SCSI and a small interleave. > > News transfers typically are 4K and are rarely larger than 64K. Your Wide > SCSI bus will transfer 4K of data twice as fast, but "twice as fast" is > really irrelevant since your process is already blocked waiting for the > data, and whether it waits 20 milliseconds of seek time plus some real > teeny number 'N' for the Wide SCSI transfer, or 20 milliseconds plus > 2 * N, is really pretty irrelevant because N is so small compared to > the 20 milliseconds you just waited for your data. > > You are better served by taking the money saved and buying more drives. > Then you are more likely to have a lower number than "20 milliseconds" > because latency is lower due to contention being lower. (The 20 number > I pulled out of the air, the argument is valid but the number may not be). What about UltraSCSI? > Exception: Wide SCSI may be useful for: > > alt.binaries (large articles) > newslib (active file, history writes) > > but I do not think it is worth the effort myself. None of my news > servers have Wide SCSI and one of them is in the Top 25. Interesting :-) > > > ---------------- ---------------- ---------------- > > > | sd0 root | | sd10 var | | sd20 newslib | > > > | 2G ST32550N | | 2G ST32550N | | CCD 1G 31055N| > > > |--------------| |--------------| |--------------| > > > | sd1 newslib | | sd11 nov | | sd21 nov | > > > | CCD 1G 31055N| | CCD 1G 31055N| | CCD 1G 31055N| > > > |--------------| |--------------| |--------------| > > > | sd2 news | | sd12 news | | sd22 alt | > > > | CCD 2G 32550N| | CCD 2G 32550N| | CCD 2G 32550N| > > > |--------------| |--------------| |--------------| > > > | sd3 alt | | sd13 binaries| | sd23 binaries| > > > | CCD 2G 32550N| | CCD 4G 15150N| | CCD 4G 15150N| > > > ---------------- ---------------- ---------------- > > > > I can see that the 2 GIG are all Barracuda's from Seagate but what > > kind of drives are the others? > > 31055N is Hawk-2 1GB "ST-31055N" "Ultra-SCSI", goes for about $330 I > believe... There is a poor cousin "31051N" version which is basically > not Ultra-SCSI but a nearly identical drive. > > 15150N is Barracuda 4GB. There is now a low profile variant out but I > have not seen them. Okay, are these drives pretty reliable? > > > Notice I stripe across controllers... also note the rants I have posted > > > in the past on CCD stripe sizes. Use large ones except for the newslib > > > disk. > > > > Hmmm, how do I do the CCD stripe? I heard you can make multiple > > drives into one partition under FreeBSD. > > man ccd :-) I will provide examples if you get lost but right now I am > busy helping one of my clients customers with a security problem... > so I will say "RTFM" and search the mailing list. Okay, will look at it. > > > With 150 readers, this is DAMN BUSY... > > > > > > Rule #1) People always try to cheap out on news servers. > > > > > > Rule #2) They fail. > > > > > > Remember those rules and you have a chance of designing a good news > > > service... > > > > Yep, that's true. Since it's better to spend more to get quality > > components than getting it cheap since by the time, you find out, you need > > to replace all the inferior components. > > Precisely.... 20% more up front saves you 120% down the road. > > That does not make it any easier to spend the 20%, untul you start > talking with someone who spent the 120% and spent several dozen > engineering hours (wasted) to find out that their hardware is crud. > That is expensive in other ways. Yep, better be safe than sorry! :-) Vince GaiaNet Corporation - Unix Networking Operations - GUS Mailing Lists Admin
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