Redhat 9, Software RAID 1

[inetd]

I have installed Redhat 9 with all the partitions are setup as software raid 1 during installation. The mirrored partitions are in hda and hdc so that it seem the two drives are mirrored. It works fine after installation. I want to simulate a drive failure and then I power off the system, unplug the hdc cable and power on the system.

However it can't boot up. The message say that it can't mount the md0,md1,... partitions and asking me to provide root password to fix the problem.

I then power off the system again, plug the hdc cable back and then power on the system. It runs as normal.

How can I successfully simulate a drive failure on RAID 1?
i.e. How can I boot the system as normal if one of the drive is damaged?

Thanks.

 

[fluid11]

To get your system to boot, you'll have to edit the configuration of your bootloader (GRUB or LILO) to boot from /dev/hda instead of the RAID device, /dev/md*.

The way that I test anything like this is to use VMware,

http://www.vmware.com.

VMware lets you run a virtual, independant operating system inside your normal OS. For example, I'm currently using VMware GSX Server to test a Red Hat Advanced Server cluster, using virtual shared storage. To test your RAID setup, you can purchase the standard Workstation edition.


...and no, I don't work for VMware

ChrisP

 

[inetd]

Hi fluid11,

You mean after I unplugged a drive and restarted the system, I should edit the GRUB to boot from /dev/hda instead of /dev/md* ? It seems something nosense on RAID 1, I think. On Windows, if a drive of a RAID 1 is damaged or removed, it can still work without any problem. Or, it is different on linux? It can't boot as normal in linux if a drive is damaged? Is it true? If so, it is not flexibility in linux.

 

[fluid11]

To be honest, I don't have much experience with software-based RAID systems, as I always use hardware-based RAID. There might be another solution, but this is the only one that I know of. Editing your bootloader to boot from /dev/hda really isn't that big of a deal. When the GRUB loader starts, you can edit the commands right from that screen. It should only take a minute.

Let me see your partition tables on the two disks?

This doc might help you...

http://www.tldp.org/HOWTO/Root-RAID-HOWTO.html

ChrisP