Emergency UNIX and Linux Support

Hi,

Currently I have 2 servers. 1 is already installed with RHEL4(withmyapplications) and the other one is still brand new.

My question is, is it possible to use DD command to backup the whole harddrive for the RHEL4 server and restore it to the new brand server so that I do not have to install it and do the works again from the start.

and if my RHEL4 server is HP prolliant and the 'brand new' server is Sun Microsystems server. is it possible to use the dd command to clone the whole disk and restore it using DD?

Because I did search using a search button on top and came up with this thread about DD, and it seems like it can not be done if I use two different servers or different harddisk brand and size.
https://www.unix.com/filesystems-disk...d-command.html

I have no idea whether it will bring any difference. Your help is greatly appreciate!

Thank You guys in advance.

If they are not identical I doubt it work..(certainly not...)
You can use dd if you have a same disk in spare to "clone" your system, but for that system only...( you have a bootable backup of your system would be more correct)

you have nothing to guarantee you have same chipsets BIOS compatibility, scsi/disk controllers, lan cards etc...

(P.S. It can be done with different size disks only if disk is greater, but you loose the extra space...)

Had it been only the data, it could had worked well ...
Unfortunately the RHEL4 system, having been configured on the server 1 would be having all the device drivers compatible to this HP server's H/w configurations.

It would still work only when you do a laborious job of replacing all such drivers and add a few extra manually. What's the point then?

The disk copy images are usually kept for the following scenarios:

1) When you fear of any crash and need to backup/preserve a well configured system.

2) To facilitates factry default in appliances, when users mess up thing in their appliance/systems settings.

3) To enable you to apply a similar setting across a number of similar machines. Eg. big corporates where IT department keep such a image to install over employees desktops.


Better Install a fresh RHEL4 on the SUN system and then mount the disk mage of this HP system as an additional storage and/or copy the data only -however, ofcourse take the dd snap of that HP machine.

Cheers!!!!!

Your guys answer is really help me to understand the use of DD.

Thanks to both of you.. appreciate it!!!