How to mirror one hdd to another hdd in linux

dkalsaria · 12-20-2008, 05:05 AM

Dear Sir,

I have installed redhat 5 in one hdd. Now i want to mirror ( raid 1 ) running hdd with new another hdd. what is the command to do mirroring. when i had tried to do the same thing, the error occured that can not open /dev/hdc: Device or Resource busy, mdadm : create aborted.
hdc is linux installed hdd. below command used.
mdadm -C /dev/md0 --level=1 --raid-devices=2 /dev/hdc /dev/hdd
Pls help me to solve the problem.

pixellany · 12-20-2008, 10:48 PM

Welcome to LQ!!

I am not aware of a way to create RAID arrays after one drive already has data. The normal procedure is to create the RAID, and then install SW, write, data, etc.

I can only GUESS that the error means you are running from the drive that you are trying to incorporate in the the RAID.

Drakeo · 12-20-2008, 10:56 PM

dd if=/dev/sda of=/dev/sdb
more info http://searchenterpriselinux.techtar...244256,00.html

pixellany · 12-21-2008, 05:24 AM

Quote:

Originally Posted by Drakeo

dd if=/dev/sda of=/dev/sdb
more info http://searchenterpriselinux.techtar...244256,00.html

I don't think that's what the question was...

Maybe it is PART of the answer---ie, once you have the same data on both drives, maybe you can tell the system to treat them as RAID-1.

Drakeo · 12-21-2008, 12:54 PM

Quote:

Originally Posted by Drakeo

dd if=/dev/sda of=/dev/sdb
more info http://searchenterpriselinux.techtar...244256,00.html

well I guess I read to fast let just make it easy how to raid.
http://tldp.org/HOWTO/Software-RAID-HOWTO.html
this gives you trouble shoot to

jschiwal · 12-21-2008, 01:05 PM

You can configure Raid-1 to use a spare. By RH 5, did you mean RHEL 5?