From owner-freebsd-hardware Fri Apr 12 21:15:38 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id VAA16927 for hardware-outgoing; Fri, 12 Apr 1996 21:15:38 -0700 (PDT) Received: from jparnas.cybercom.net (jparnas.cybercom.net [205.198.82.58]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id VAA16918 for ; Fri, 12 Apr 1996 21:15:23 -0700 (PDT) Received: from localhost.cybercom.net (localhost.cybercom.net [127.0.0.1]) by jparnas.cybercom.net (8.6.10/8.6.10) with SMTP id AAA00142; Sat, 13 Apr 1996 00:12:57 -0400 Message-Id: <199604130412.AAA00142@jparnas.cybercom.net> X-Authentication-Warning: jparnas.cybercom.net: Host localhost.cybercom.net didn't use HELO protocol To: scott@statsci.com cc: Chris Stenton , hardware@freebsd.org X-External-Networks: yes Subject: Re: Micropolis 1991 AV 9GB Drive In-reply-to: Your message of Fri, 12 Apr 1996 12:05:36 PDT. Date: Sat, 13 Apr 1996 00:12:55 -0400 From: "Jacob M. Parnas" Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk In message you write: >Chris Stenton wrote: > >> Is there a better 9GB drive I should be going for ... any advice would >> be appreciated. > 9 GB drives have advantages and disadvantages. The main advantage is especially for large servers, You can get more disk space on it. I think most of the other problems aren't too bad. You should be doing nightly backups on data you'd really miss losing. Last I checked, the 4.3 gig drives were a bit faster and used less power and may be smaller (not sure about the latter). Also, more disks running in parallel is an advantage as is leaving some physical space and controller slots available for future breakthroughs. If one can distribute the load over a bunch of disks, one can speed things up as one can if one makes the disks. If your working on an existing system, its really useful to have a feeling for where their bottleneck is in their system, be it cpupower, video card, disk, disk controller, disk type, disk controller type, etc. Use tools like periodic ps aux or ps vax into a file during problem times in the day. Read a good book on Unix performance tuning. (I think there's one bye Mike Loukides (an O'reilly book). You may need more memory or cache. You may need a faster network or file server or to have the disk local vs. via file-server. You need to figure out where the problem is. An archive source disk may be fine for something where it would be bad as a "one disk does it all" disk. I think some OS's can combine disks into virtual bigger disks for large filesystems. To be honest, I don't know if BSDI can do that. But if not, and you might have some large space for big file or database. Also, don't be shy about using the excellent program gzip/gunzip which can be used recuseively with the -r. It is great for saving space. Most source code can be made distclean to almost its original size and then gzip -r it for storage. Big things like X windows source can easily taped and removed from disks. Finally, I've heard, but not tested, that having extra controllers (fewer disks per controller). I'd try to get access to a lot of systems or get eval units or 30 day net controllers and calculate good transfer rates for a disk, etc. Hope that helps, Jacob