There is a huge difference between RAID5 and RAID10. Software-RAID5 should be avoided as it is CPU intensive and there are many good true hardware solutions for it that are supported in Linux. On Fri, 2 Sep 2005, Francisco Perez wrote: > Date: Fri, 02 Sep 2005 20:24:44 -0500 > From: Francisco Perez > Reply-To: gentoo-amd64@lists.gentoo.org > To: gentoo-amd64@lists.gentoo.org > Subject: Re: [gentoo-amd64] Upgrading to Raid > > Correct me if I am wrong since I have yet to have to deal with restoring > failed disk in an array, but in a hardware raid, with my card I would just > enter the card's bios after rebooting and then restore the new replacement > drive from the secondary image (remember I am using raid 10 with 4 disks.) > Is there something I'm forgetting? > > Frank > > Florian D. wrote: >> because there are so many people praising software-raid, you´ll probably >> find this story interesting, which happened to me yesterday (my system is >> -for the biggest part- on a raid5 partition): >> >> while I emerged koffice, played some mp3´s and let matlab calculate sth. >> in the background, I tried to start a windows program with wine. I really >> shouldn´t do that, because Linux crashed and after a hard reboot it could >> not boot any more. It stopped during the execution of the init-scripts and >> i was not able to do anything, thus: 2nd hard reboot. I have another(old) >> gentoo installation on my computer and this time I booted into that one. >> By accident I realized that one of the discs of my raid system has been >> marked as faulty and it was syncing in the background. /proc/mdstat said >> that it would need 20min or so, but after 15min it said 200min! After >> another 10min it was sth >300min (and a lot of IO errors). So I rebooted >> again, this time it synced successfully in 12min. Then it was possible to >> boot and work with my normal system without any further difficulties or IO >> errors. >> >> Summing up, I can say: >> >> + I successfully wrecked my file system, but software raid was able to >> repair it >> - without a second Linux-installation on another partition, you´re lost >> - restoring of a faulty raid disk is not reliable >> - it seems that it is not possible to boot or work with a system, whose >> system disk is being restored at the same time (Linux-2.6.12.6) >