[CentOS] Mirroring Hard Drive

Sun Dec 7 19:46:37 UTC 2008
Matt <lm7812 at gmail.com>

>> I have a 500GB Sata drive about 15% used I would like to make an exact
>> copy of too another Sata 500GB drive as a spare.  That way if
>> something happens to the one in service I can plug in the spare
>> quickly and restore one of the weekly backups without reinstalling the
>> entire OS and all the little tweaks of setup on this mail/web server.
>>
>> How do I do this?  That is make an exact bootable copy of a linux
>> drive.  Its running Centos 4.6 if that matters.
>>
>
>
> brute force approach...
>
>   dd if=/dev/sda of=/dev/sdb bs=16384
>
> that will copy the whole physical drive.   I would do this in single user
> mode (init 1) for best results, as any changes to the file system while a
> copy is in progress will be inconsistent

Can I use this to copy from a single 500GB SATA drive with only 54GB
in use to a hardware RAID 1 drive of 300GB?  The RAID will be two
300GB SATA drives.

Matt