After installing a RAID 1 system, you should not shutdown the system until the system has a chance to complete the sync of both disks. Maybe this is the reason for your problem. I'm a little confused why you want to deactivate the second channel and reactivate it once a week to resync. I have systems that have run with both disks for 4 years or more without any problems. I think this is the way it is supposed to work. The way you are doing it you are better off not configuring the system as RAID and simply doing a manual sync once a week. Timmy wrote: > Hi Roelof and others: > I uninstalled the SiI software raid card and installed SL 5.1 again! SL > 5.1 seemed to be able to set up a RAID pair by itself even without the > add-on raid card! Everything was very smooth. > > My config is: > 2 x 160GB SATA harddisks installed on 2 separate SATA channels. > > My idea is to keep one hardisk as working system disk 24 hours (science > calculation, business, BT, everything etc and therefore it will be worn > out to death easily ;) and the other harddisk as Spare disk. It will > be rebuilt and cloned per week against the working system disk. Another > file backup software will take care the incremental backup everyday! > Sound very perfect! ;) > > Ok! After the above mentioned SL 5.1 system was built and became stable, > I shut down the computer. Then, I turned on the computer and > deactivated the 2nd SATA harddisk (named sdb) from within BIOS. SL 5.1 > booted with the single hardisk(sda) successfully (It claimed Degraded > RAID mirror when SL 5.1 started up). I ran the system for a few days. > Then, I activated sdb again and hoped that SL 5.1 could rebuild it and > cloned sda to it. However, SL 5.1 claimed that it could not find many > files and stopped at the command prompt. I rebooted the computer, > deactivated sdb again in the BIOS and booted to SL 5.1 successfully with > only sda again! > > So, I face a problem: How to REBUILD / CLONE sda to sdb with Linux > command mdadm?? :(( > > > Timmy > > P.S. After I had unplugged the SiI software SATA RAID card, SL 5.1 > never stops at RedHat Nash 5.19.6 ..... any more. I guess this model of > card is not compatible with the current SL 5.1! Avoid it! :(( > > >> I never understood why redhat included the alpha quality dm-raid >> drivers. I call this alpha, since basic functionality like rebuilding >> a raidset (!) still is missing. DM-raid is a kludge to be able to do >> dual-boot with a windows system using these raid drivers. >> Never, ever use dm-raid on a server. Use mdadm instead. It performs >> just as well (dm-raid is also softwaid after all) and it is stable. >> If you only need mirroring, you can also use LVM to create a mirror. >> (I never used that myself, YMMV) >> >> Another advantage of mdadm is that it is hardware independent. Your >> raidsets will keep on working even when transferred to a different >> brand of sata controller. >> >> By the way: if you try to install an mdadm based raid system on a >> drive that previously has been part of an intel/promise/highpoint raid >> set, it will probably fail after the first reboot. This is because >> the dm-raid system is not active during the anaconda run, but is >> activated before mdadm in the regular startup. DM-raid will detect the >> old raid signature and lock the disk, preventing mdadm from using is. >> Apart from a complete disk wipe, you can set the 'nodmraid' kernel >> parameter in grub to prevent this from happening. Destroying the old >> raid-set using the bios tool before installing mdadm often will not >> work in my experience. >> >> Roelof >> >> Timmy wrote: >>> I have installed SL 5.1 many times! The file system can be corrupted >>> easily! I don't know whether it is RedHat Linux's weakness. Here >>> are my experiences: >>> Case 1. >>> The system might stop here at boot time: >>> RedHat Nash 5.1.19....... >>> >>> After rebooting, it might boot normally or the system went corrupted >>> and no more boot again! >>> >>> >>> Case 2. >>> I installed 2 SATA harddisks as mirror pair on a SiI SATA software >>> RAID card. Installation is successful but after several days' >>> operation, the system could not read the RAID pair. Formatting was >>> needed. >>> >>> >>> Case 3. >>> After several days' downloading of a movie file through Ktorrent, the >>> file system went corrupted again! Formatting harddisk required. >>> >>> I heard that downloading BT file hurts hard disk very much. However, >>> Case 1 and Case 2 do not have any relationship with BT task. >>> >>> Any technique or trick to avoid this?