From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Benecke Subject: Re: Q: RAID-1 w/2x160GB, ReiserFS, Debian 'woody', homebrew 2.4.25 kernel Date: Thu, 05 Aug 2004 08:16:53 +0200 Sender: linux-raid-owner@vger.kernel.org Message-ID: References: <27897.194.60.85.4.1091613610.squirrel@194.60.85.4> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Robin Bowes wrote: > On Wed, August 4, 2004 9:42, Jens Benecke said: >> I'm planning to set up a new RAID mirrored system with the above spe= cs. >> Both disks are master (hda and hdc). I'm currently trying to decide >> between LVM2 (is it in 2.4 already?), MD, and a "manual" nightly rsy= nc >> onto the second disk. >=20 > I use md and mdadm on Fedora Core 2. What distro are you contemplatin= g? Hi, see subject (Debian). I've looked at SuSE though, it seems with their s= etup RAID and ReiserFS is much easier to handle. I'm running SuSE at home th= ough and the sheer number of security updates that come in kind of make me a= bit uneasy for an internet server. =20 >> How about RAIDing the root partition? If one drive fails will the ot= her >> be able to boot via LILO? How about GRUB? Which do you prefer? >=20 > I have my root partition on a RAID1 mirror. I use grub and have > "installed" grub to both mirrored drives so I can boot off either, e.= g. if > one fails. That reminds me, I must test this. That's exactly what I want. =20 >> How about (/var)/tmp? I (suppose I'll) need it on both disks, does i= t >> make sense to mirror it as well? >=20 > You *could* put /var/tmp or /tmp on separate partitions either mirror= ed or > not, but if you want to keep things "stress free" I would keep /var/t= mp > and /tmp on the root partition. No. I don't want a rogue script to fill up my root partition. =20 >> Can I mirror the whole disk? Or do I need to mirror each partition >> seperately? >=20 > You can do either. You mirror the disk using md and can then either c= reate > a filesystem on the whole disk, or use lvm to create logical volumes > within the md device. Hm... I thought LVM did mirroring and striping as well? I didn't think = you can or should use them together. Wouldn't that degrade performance as w= ell? =20 >> Does MD or LVM2 do hot sync, i.e. if one drive fails will I be able = to >> stick in a replacement, and stop worrying? Or do I need to repartiti= on >> the new disk exactly as the old one, before being able to sync? >=20 > I'm not sure about this. My understanding is that you will need to > shutdown the system to replace the bad disk and partition the new dis= k > manually before md will resync, but this could be wrong. What I mean is, will md resync automatically or would I have to initiat= e this manually? =20 > I have six 250GB SATA disks, all partitioned identically with two > partitions of 1.5GB and 248.5 GB. I have them configured as RAID devi= ces > using md follows: I think you mean 1.5TB. :-) =20 > md0 sda1 + sdd1 RAID1 1.5GB root filesystem > md2 sdb1 + sde1 RAID1 1.5GB swap 1 > md3 sdc1 + sdf1 RAID1 1.5GB currently not used > md5 sd[abcdef]2 RAID5 994GB lvm2 volume group (4+1+spare) >=20 > Then within the lvm2 volume group I have the following logical volume= s: >=20 > dude_usr 10GB /usr > dude_var 5GB /var > dude_home 979GB /home >=20 > I did my initial install just to the mirrored root parition . Once I = had > done the initial install I set up the lvm2 array and volumes and migr= ated > /usr and /var over. >=20 > It's working great so far. This setup seems quite complicated. Did you test the setup, ie. removed= one of the MD disks and looked what happened? =20 >> The goal is to have as "stress free" a system as possible - i.e. wit= h as >> little manual configuration, and in event of emergencies, as little = work >> to do, as possible. >=20 > If you want stress free, buy a Netapps storage appliance ;o) If they do all the rest that I need (smtp, web, file server, ftp server= , mysql, spamassassin, etc etc etc) fine. If not, I'd need to set up anot= her box anyway, so I wouldn't see the advantage. --=20 Jens Benecke http://www.hitchhikers.de - Europas kostenlose Mitfahrzentrale seit 199= 8 http://www.rb-hosting.de - Webhosting mit Extras - PHP ab =A49 - SSH ab= =A419 http://www.spamfreemail.de - 100% saubere Postf=E4cher, garantiert! - To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html