mkraid or mdadm will work, just be very sure you use the correct options. As long as the system does not attempt a re-sync, the data will not be destroyed. But if you get the parameters wrong and a re-sync starts, expect data to be lost. So, keep 1 disk missing until you are sure you have it right! One of the parameters that must be correct: "parity-algorithm". If you used mkraid your /etc/raidtab file should have what you need. You will need to use the "failed-disk" keyword. See "man raidtab". I am not sure how to use it. So be careful! Guy -----Original Message----- From: Dominik Sennfelder [mailto:Sennfelder@xxxxxx] Sent: Friday, May 21, 2004 4:59 PM To: Guy Cc: linux-raid@xxxxxxxxxxxxxxx Subject: RE: Raid Failed What to to Hello Thanks for your help. I created the array with mkraid /dev/md0 after i added the entrys in /etc/raidtab. I analyzed the logs an saw that one disk failed one day before, so the raid run with 3 discs. My fault was to raidsetfault the wrong drive. But in that moment the Raid broke up an no write was possilble because it got remountet -ro. After i hotadded it again, it tried to sync but with only two discs syncing wouldn't be possible. The drive i removed wan't really faulty, it was just set faulty. I even could browse the filesystem when just 2 discs run. So can i reassamble the drive mith mdadm? or do i have to use mkraid? Thanks for your help and suggestions. Dominik > This is an example for using mdadm where the second of three disks is bad. > But you must use the same chunk size and other RAID5 parameters or the > array > will have bogus data. It would be nice if you still have the original > command you used to create the array. > > mdadm -C /dev/md0 -l 5 -n 3 /dev/hda3 missing /dev/hdc3 > > Guy > > -----Original Message----- > From: Guy [mailto:bugzilla@xxxxxxxxxxxxxxxx] > Sent: Friday, May 21, 2004 10:00 AM > To: 'Clemens Schwaighofer'; 'Dominik Sennfelder' > Cc: 'linux-raid@xxxxxxxxxxxxxxx' > Subject: RE: Raid Failed What to to > > If you re-make the array with the same parameters as it has now the data > will not be lost (assuming it is still there now). If 1 disk is really > bad > then leave it out. > > The procedures depend on which program you use to create the array. Do > you > use mkraid or mdadm? > > Guy > > -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx > [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Clemens > Schwaighofer > Sent: Friday, May 21, 2004 4:45 AM > To: Dominik Sennfelder > Cc: linux-raid@xxxxxxxxxxxxxxx > Subject: Re: Raid Failed What to to > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Dominik Sennfelder wrote: > | Hello > | > | I have got a Raid 5 with 4 160 GB Disk, > | On of the Disks Failed because. But I know its OK I had this for some > | times. > | A Restart solved The Problem. > | But now Tried to raidhotremove the Drive and removed the wrong drive. > | I just recongized the Problem after i raidhotadded itagain. > | No the Raid tries to sync again. > > well if you removed two drives from your Raid5 array, it might got > competly out of sync and then there is no way to recover. I have never > tried this with my raid, but if you add another disk it well be > re-synced, ergo it tries to rebuild the array out of the CRCs on the > other drives, if you remove two, you don't have enough redudant data to > do this (raid 6 can recover from a 2 drive failure). > > I hope you have a backup. > > - -- > Clemens Schwaighofer - IT Engineer & System Administration > ========================================================== > TEQUILA\Japan, 6-17-2 Ginza Chuo-ku, Tokyo 104-8167, JAPAN > Tel: +81-(0)3-3545-7703 Fax: +81-(0)3-3545-7343 > http://www.tequila.co.jp > ========================================================== > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.2.4 (GNU/Linux) > > iD8DBQFArcGmjBz/yQjBxz8RAkYKAJ9TAc03OnmIth/M03xBmopKerZLOQCcCiiG > wk/lAjdcrd1jPWSoLyOGLAE= > =5uyj > -----END PGP SIGNATURE----- > - > 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 > > -- Mfg Dominik Sennfelder -------------- Sennfelder@xxxxxx IRC: #spooky ICQ: 18164192 Blue Skies - 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
