> -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx > [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Jens Benecke > Sent: 05 August 2004 06:17 > To: linux-raid@xxxxxxxxxxxxxxx > Subject: Re: Q: RAID-1 w/2x160GB, ReiserFS, Debian 'woody', > homebrew 2.4.25 kernel > > Robin Bowes wrote: > > > On Wed, August 4, 2004 9:42, Jens Benecke said: > > > > 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. Ooops./ I didn't read the subject. > >> 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. I've got some rough notes I made. I may tidy them up and publish them on my web site. > >> 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. That, of course, is the reason you would want to keep /var/tmp and/or /tmp on separate partitions (or on the same partition - just symlink so /var/tmp and /tmp are the same.) > > >> 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? Md should re-sync automatically. > > > 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. :-) Nope, 1.5GB. See below. > > > 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? I deliberated long and hard about how to implement my new system and this was about the least complicated route! > >> 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. I was being slightly slippant - Netapps just do big storage arrays with very high availability. For example, if they detect that a drive is failing they send an email to Netapps and an engineer comes round with a replacement disk all without any user intervention! I guess they're the Rolls Royce of storage solutions. Expensive though. R. -- http://robinbowes.com - 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
