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 specs. >> 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 rsync >> onto the second disk. > > I use md and mdadm on Fedora Core 2. What distro are you contemplating? Hi, see subject (Debian). I've looked at SuSE though, it seems with their setup RAID and ReiserFS is much easier to handle. I'm running SuSE at home though and the sheer number of security updates that come in kind of make me a bit uneasy for an internet server. >> How about RAIDing the root partition? If one drive fails will the other >> be able to boot via LILO? How about GRUB? Which do you prefer? > > 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. >> How about (/var)/tmp? I (suppose I'll) need it on both disks, does it >> make sense to mirror it as well? > > You *could* put /var/tmp or /tmp on separate partitions either mirrored or > not, but if you want to keep things "stress free" I would keep /var/tmp > and /tmp on the root partition. No. I don't want a rogue script to fill up my root partition. >> Can I mirror the whole disk? Or do I need to mirror each partition >> seperately? > > You can do either. You mirror the disk using md and can then either create > 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 well? >> 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 repartition >> the new disk exactly as the old one, before being able to sync? > > 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 disk > manually before md will resync, but this could be wrong. What I mean is, will md resync automatically or would I have to initiate this manually? > 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 devices > using md follows: I think you mean 1.5TB. :-) > 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) > > Then within the lvm2 volume group I have the following logical volumes: > > dude_usr 10GB /usr > dude_var 5GB /var > dude_home 979GB /home > > 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 migrated > /usr and /var over. > > 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? >> The goal is to have as "stress free" a system as possible - i.e. with as >> little manual configuration, and in event of emergencies, as little work >> to do, as possible. > > 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 another box anyway, so I wouldn't see the advantage. -- Jens Benecke http://www.hitchhikers.de - Europas kostenlose Mitfahrzentrale seit 1998 http://www.rb-hosting.de - Webhosting mit Extras - PHP ab €9 - SSH ab €19 http://www.spamfreemail.de - 100% saubere Postfächer, garantiert! - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
