ben@relay.eu.net (Ben Lippolt) (02/15/90)
In the near future we expect to have the following situation: about 10 SUN-3's (2 or 3 diskless, the others have local swap-disks), some Sparcstations (starting with 3 but slowly increasing), and about 40 PC's with PC-NFS. I proposed a solution with a SparcServer (370 or 390 with about 1 Gb disk), but our computer-department doesn't like Sun that much (they're in favor of Digital). They agree that we need a fast server, but think a DEC-machine (or perhaps some other brand) could do the job. My questions are: - Which power should the server have? My sales-rep said that Sparcstations shouldn't be served by a slow machine (SUN-3 or VAX-785 class). He also said that the CPU-power (ie. MIPS) plays a role in the capacity of the server, because a faster machine could utilise the ethernet-interface better. - In case of a DEC-server, which one would be sufficient? - Is it possible to boot SUNs from a non-SUN machine? - Which solution do YOU favor, a SparcServer-3X0 or a DEC fileserver? Thanks for any info. Ben J. Lippolt PTT Research Neher Laboratories [ E-mail : BJ_Lippolt@pttrnl.nl ] P.O. Box 421, 2260 AK Leidschendam, [ BITnet : LIPPOLT@HLSDNL5 ] The Netherlands. Tel: +31 70 3325439 [ UUCP : hp4nl!dnlunx!lippolt ]
beaulieu@uunet.uu.net (Larry Beaulieu) (02/20/90)
In article <5023@brazos.Rice.edu>, dnlunx!odin!ben@relay.eu.net (Ben Lippolt) writes: > My questions are: > - Which power should the server have? If you're going to be stuck with using DEC, forget anything less than a 64xx (er, 6000 series 4xxx) or 5800 series (MIPs based) system. A SCSI or Q-bus based VAX just won't have the I/O horsepower required, never mind a Massbus system, and the Q-bus on the 5400 is not a great performer, either (3-5 MB/second). This gives you 7-36 MIPS to play with, depending upon the number and type of CPU. We used a 780 (configured for maximum I/O performance; 2 Unibus, 1 UDA50 per bus, 1 RA drive per controller) to service 5 standalone 3/60's mounting the user directories only while waiting for our Sun server. The users were much happier after the 3/280 came in and we made the 3/60's dataless. In general, your server should offer CPU performance comparable to that of the clients. Therefore, the VAX would be marginal, but the MIPS box would be fine, as well as a Sparcserver 370/390 using SMD or IPI drives. ( but do you want to back up on a cartridge drive on a 370?) Noteworthy points: - With DEC, you are stuck with a single or twin (ASMP) CPU model, since Ultrix doesn't yet support SMP. If you can get a MIPS based system, so much the better, @ 18 MIPS per CPU vs 7 for the VAX. - A BI bus is rated at 13.3 MB/sec, vs. the 40 MB/second for VME. The DEC systems use an 80MB/second bus (XMI) to house the CPU's, with the BI bus used as an I/O bus. You can get multiple BI buses on a system. The actual throughput on the VME bus for I/O on the higher end Suns is supposedly approximately 16 MB/second. - Ultrix does not yet support HSC's to boost I/O throughput, so - Beware of MIS types pushing for the VMS/Ultrix connection product from DEC. Everyone I've spoken to who as an opinion has generally been negative. - An 8000 series VAX cannot adequately support a bunch of DECstation 3100's (per a senior engineer at Spitbrook); the DECstations demand too much from the poor beast. Given a DECstation 3100 approximates a Sparcstation 1 (in rough terms, no wars please) one could draw the same analogy using a Sparcstation. > - In case of a DEC-server, which one would be sufficient? As I imply above, a 5810 should be fine, expecially if equipped with multiple BI buses (use multiple disk controllers spread out between the buses). If you must have a VAX, then a 6420 (6000 model 420) would be better. See the next paragraph, though. > - Is it possible to boot SUNs from a non-SUN machine? No. You could, however, have a dual server configuration where the Sun's boot off another Sun and mount the user directories (/usr/users, etc. off the DEC server). I suppose it would be possible to make it work, if you wanted to spend the time and effort to do so, as well as write some software. > - Which solution do YOU favor, a SparcServer-3X0 or a DEC fileserver? 1) The SparcServer can service all the needs for your Sparc and Motorola 680x0 based Suns as it comes out of the box. The same cannot be said for any of the DEC systems, although I suspect a high end DEC server could severely thump a SparcServer, for a given load. 2) Do you really want to have a multi-vendor development environment when you don't have to? In this case, I would go with the Sun. Larry Beaulieu ...uunet!gca!beaulieu SMTS/Software Engineer GCA Corporation, "Live to step, step to live..." Andover, MA