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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!nntp.coast.net!news.sgi.com!enews.sgi.com!news.mathworks.com!uunet!in2.uu.net!news.gtn.com!klemm.gtn.com!usenet From: andreas@klemm.gtn.com (Andreas Klemm) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: How can i do this? =) Date: 25 Sep 1996 14:23:26 GMT Organization: FreeBSD makes fun Lines: 62 Message-ID: <52bf8u$d8e@klemm.gtn.com> References: <518j75$flf@cantina.clinet.fi> NNTP-Posting-Host: klemm.gtn.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Newsreader: knews 0.9.8 In article <518j75$flf@cantina.clinet.fi>, mickey@cantina.clinet.fi (Mika Ruohotie) writes: > > i tried to rtfm, but found no clue how to do this: > > i'm setting up a server where i will use three identical hard drives, > it was trivia to figure out how to strip two drives, but i want to > mirror to the third... > > is it possible? Dunno, but I'd not stripe or mirror, I'd use the three disks, to spread the SCSI workload over 3 different scsi disks ... Make a daily backup of the three ... Look here, what I did with 2 harddisks: Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/sd0a 31775 11241 17992 38% / /dev/sd0s3e 63567 34724 23758 59% /www /dev/sd0s3f 127151 12432 104547 11% /var /dev/sd0s3g 765058 389556 314298 55% /usr /dev/sd1s1e 193855 74638 103709 42% /news /dev/sd1s1f 1790627 1261822 385555 77% /local procfs 4 4 0 100% /proc mfs:23 63567 4 58478 0% /tmp /dev/cd0a 640690 640690 0 100% /cdrom Swap space is on each disk. So the system cam make use of delayed swapping. You could do that over 3 disks if you like. News is on another disk than the UUCP spool dir ... So inn's rnews process reads from the one disk and inn writes into the spool dir on the other disk. My CVS repository is located on one disk (/local/cvs), when I checkout sources I write them to the other disk (/usr/src). When I do a make world, the I locate the .o files (the /usr/obj tree) via a symlink to the other disk, so cpp, compiler and assembler (and friends) read from the on ans write to the other disk ... If something goes wrong ... have a good backup ... Disk mirroring is too expensive, you'd need 4 disks ... Disk stiping with parity is probably not supported and has a not so good write performance... So, better split the SCSI load as suggested ;-)) If you really need something like striping, then better get an external chassis with hot fixing possibility ! (My humble opineon). Andreas /// -- andreas@klemm.gtn.com /\/\___ Wiechers & Partner Datentechnik GmbH Andreas Klemm ___/\/\/ Support Unix -- andreas.klemm@wup.de pgp p-key http://www-swiss.ai.mit.edu/~bal/pks-toplev.html >>> powered by <<< ftp://sunsite.unc.edu/pub/Linux/system/Printing/aps-491.tgz >>> FreeBSD <<<