Centos software raid install

If there are spare disks available, and if the system survived the crash, reconstruction of the mirror will immediately begin on one of the spare disks, after detection of the drive fault.

If two drives fail, all data is lost. If spare disks are available, reconstruction will begin immediately after the device failure. If two disks fail simultaneously, all data are lost.

RAID-5 can survive one disk failure, but not two or more. Skip to primary navigation Skip to main content Skip to primary sidebar Skip to footer navigation. So long as you use grub to install the boot sector on both drives, then you can always tell the BIOS to boot from the other drive to bring the system up after replacing the first disk.

If this machine you purchased was some name brand, you must be speaking about hardware raid, true? Also, most name brand servers give you a bootable machine day one.

If you are using software raid, you must have configured it yourself. Here is what my custom machine has:. During my CentOS 7 install is where I performed the software raid-1 configuration. I never do the default partition configuration so here is my setup used fdisk -l :. Start End Size Type Name 1 Thank you. Hmm, OK. Cheers Tony. Some Googling suggests this problem is related to the lack of "persistent superblocks", but I could use some guidance on how to proceed.

Thanks, Barry. I screwed it up several times before I got it right the first time. Re: Software RAID after installation Post by bjskidmore » Sat Apr 08, pm [quote]Did you format the partition and then create a degraded raid1 from it OR did you create the degraded raid1 and then format the md device?

If everyone doesn't mind I would like to summarize the steps taken, as there were a couple other problems that occured that might give you ideas concerning the problem.

As an aside, I have attempted this now 7 times without success, but seem to be getting a little farther each time. Reboot gets to point where it begins a file system check, then receive the following error: Checking root filesystem fsck. I think what has happened is that the fs from the original drive is being checked. You will be overwriting those settings when you initiate raid recovery. Up until the moment you initiate raid recovery, your original drive should remain untouched, except for making initrd images with raid1 support which also need to be copied to the new md drive.

The mkinitrd error message suggests a failure in making a proper initrd image. Changing the grub. Also, be sure to make backup copies of the original initrd images if you plan to overwrite the originals.

You need to boot from the degraded raid hd1,0 , not from the original drive. At this point, the original drive should still contain the original grub. The only problem with booting from the degraded raid1 is my comment from the previous post that I was unable to install grub on that drive: [quote]9.