Date: Wed, 17 Jul 2002 22:28:41 +1200 From: "Tortise@Paradise" <tortise@paradise.net.nz> To: <freebsd-stable@freebsd.org> Subject: Re: Software raid 1 on root partition? Message-ID: <011701c22d7c$b929bc70$0600a8c0@P1200n> References: <25f401c228d4$a3482fb0$1a01000a@area51> <20020711091015.B51520@flake.decibel.org> <20020711200902.3653b534.steve@sohara.org> <20020713032546.GD61459@wantadilla.lemis.com> <20020713075109.06ecf02f.steve@sohara.org> <20020713100218.B284@twincat.vladsempire.net> <20020713222745.00281f72.steve@sohara.org> <20020714004247.GB16279@wantadilla.lemis.com> <20020714071524.1587f419.steve@sohara.org> <20020716131850.GB28928@luke.immure.com>
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> I have been assuming (no confirmation as I haven't tried this yet) > that the recovery process is to dump the file systems on the RAID1 > configuration, replace the dead disk, reconfigure/newfs the filesystem, > and then restore it. Certainly not ideal, but it still beats losing the > data I think. The only part of this that I'm uncertain about is access > to the array while one of its disks is dead. Well if it didn't reliably work there would be no (well little) point in it.....RAID 1 that is. > BTW, I've been running a RAID0+1 (striped and mirrored) configuration of > 4 80GB IBM disks on this system for over a month now. If you are feeling game you could reproduce the scenario artificially.....unplug one HDD power cable......when the servers not busy.....and prove it continues to work..... Or perhaps replace one HDD with a blank equivalent and see what happens..... But don't blame me for any adverse consequences...... But if there are they were likely waiting to happen anyway..... The thing about HDD failure is that the question is not if it will occur, but rather when it will occur....and how prepared were you? For one windows server I use a RAID 1 IDE setup. Somewhat like Jack Stone's described system. The HDD/filesystems are mirrored. My variation is to have a third IDE Drive which is externally plugged in. (One RAID ide drive internal, the second externally cold swappable) This external drive is swapped and "restored" whenever a significant OS/software change is made, so I have an offsite working HDD, along with a spare RAID card. That server can then be reconstructed without too much angst (eg in the event of fire....theft etc) and updated with the more minor critical file backups I also maintain off site. It also tests to some degree the backup reliability and seeing it work is encouraging..... This system has yet to fail and be "properly" tested, but the artificial planned tests (drive swaps) have all worked fine. Thanks indeed for the interesting contributions. I feared the issue might be seen to be too "low level". I have plenty of homework scope here.....LOL...to recreate something similar in FreeBSD that I can be confident in and that has an acceptable cost/reliability/recovery time balance. David Hingston MB ChB MBA _________________________________________________________________________ tortoise@paradise.net.nz http://hingston.yi.org/ http://pcmc.yi.org/ If you seek a digitally signed response please advise. If you received a warning on reading this e-mail, please go to http://www.baycorpid.com/settings/email.asp?CA=healthcert to update your settings To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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