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Newsgroups: comp.unix.bsd.netbsd.misc Path: sserve!euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!zombie.ncsc.mil!news.mathworks.com!uunet!in1.uu.net!world!dawg From: dawg@world.std.com (Dean Anderson) Subject: Re: NetBSD Filesystems Message-ID: <DCr4xH.791@world.std.com> Organization: The World Public Access UNIX, Brookline, MA References: <1995Jul26.123455.28242@lssec.bt.co.uk> <MICHAELV.95Jul30182230@MindBender.HeadCandy.com> <3vjcve$mah@wolfe.wimsey.com> <3vkrtd$hn5@news.cloud9.net> Date: Thu, 3 Aug 1995 20:29:41 GMT Lines: 30 >>It is asking for trouble. If you really need fast writes on lots >>of small files (i.e., for a news filesystem or something like that) >>the proper thing is to use the log filesystem or something similar. Actually, if you want fast writes, the sysV fs is pretty good. Although the penalty is read performance due to fragmentation and lack of locality. But it can find free inodes and free blocks faster than ffs. How do you get one? OSF/1 had a sysv filesystem, but unfortunately I don't know whether it is redistributable or not. But I'm pretty sure it was a re-implementation from spec, and most of the things that OSF implemented itself (like the loader, for example) were given a free redistribution copyright. As for the best all-around fs, I'd have to say the WAFL filesystem in the Network Appliance box is the best thing I've seen so far. Essentially, files and metadata are copy-on-write, so nothing is really pinned down, and disk writes can be made wherever it is convenient--ie, where the disk head is now... One can make snapshots at any time, and combined with nvram and regularly scheduled snapshots, the system is always consistent, or can be brought up to date by rolling back to the last snapshot and looking in the nvram. It probably suffers from fragmentation, etc for the same reasons the sysV filesystem does, but there is also a raid 4 system, which probably makes up for this with a lot of spindles. --Dean -- Dean Anderson dawg@world.std.com President Contact me for more info League for Programming Freedom or send mail to lpf@lpf.org