[CentOS] Re: raid1 disk format?

Les Mikesell lesmikesell at gmail.com
Thu Jun 12 19:50:17 UTC 2008

Ross S. W. Walker wrote:
>> You can't beat dd for getting everything exactly the same regardless of 
>> what you changed - or just splitting the mirrors and letting each sync 
>> to new partners but then you have to reinstall grub.  I prefer 
>> clonezilla for non-raid configurations but most of the machines I care 
>> about are configured with raid1.
> Well, actually dd isn't so good in this area. dd will do the whole disk
> no matter how much data is actually stored on it and for a 500GB disk
> that can take a lot of time. 

Sure, but it isn't human time.  I just give the command and come back later.

> It also doesn't take into consideration
> any disk geometry differences.

I happen to have a lot of identical disks in swappable carriers.

> A better way is to use kickstart script to automate a network install
> and then to use dump/restore to load the user/application data back.

Sounds like more work to me. Besides figuring out the kickstart options 
  you need an up-to-the-minute dump made beforehand and there's always 
some risk in restoring running programs unless you use a program like 
rsync that creates a tmp name, then renames when complete.  And there's 
some work to sort out what you can restore and what you can't.

> With remote access cards and vnc kickstart installs this can even be
> done remotely on a headless server even without a technician present
> to power it on or off.

Shipping a box of disks for someone else to swap in works for me, and it 
doesn't matter if you decide to drastically change OS's between swaps. 
You do have to deal with the way NIC detection has changed across Centos 
versions, though.

   Les Mikesell
    lesmikesell at gmail.com

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