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My (postfix) mail server currently runs on an old PowerEdge 2650 and it badly needs a hardware upgrade.

I would like to put it on an 8 core (3rd Gen) 2950, but have no idea how to go about changing hardware. Do I have to install CentOS on the new machine and then figure out how to get postfix/mailman/ldap all working on the new one? Is there any type of information on how to do this? I have no idea how modular linux ACTUALLY is. If I install a new version of CentOS 5.4, should I technically be able to copy over /var /usr /root /home /etc and have the server work exactly the same but on the new hardware? Or would I need to recompile certain programs? I feel like I never learned these type of things anywhere.

Or what if I ran clonezilla on the server and tried to restore it to the new hardware? Would I need to recompile/update the kernel?

Thanks for any help/input/direction.

Luke
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2 Answers2

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How about this for a "not-what-you-were-expecting answer". :)

Virtualize the sucker.

Download the free version of VMware's ESXi and install it on the 2950. Then use the (also free) VMware Converter product to do a P2V migration of the mailserver from its current hardware into the new virtualized server. Doing this will provide the following benefits:

  1. VMware Converter does a very good job of making sure that all necessary drivers are installed on the guest OS so that you don't have any compatibility problems after migration.
  2. After pulling the system into VMware, you will no longer be tied to a certain hardware platform. Want to upgrade again 2 years from now? Simple, install ESXi on the new server and copy the backing vmdk/vmx/etc. over.
  3. You'll be able to get better utilization out of the server. It's quite unlikely that you're using all the available memory, CPU, and disk resources this hardware has to offer. By inserting a virtualization solution into the mix, you'll be able to spin up additional virtual machines when needed with no additional hardware costs.
  4. The P2V conversion is 100% read-only. So if things do not go well for whatever reason, just boot up your original server and try again some other time.
EEAA
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  • I like it. But to my knowledge CentOS isn't supported by VMware converter? Also I should mention that the server is 32bit... – Luke Sep 13 '11 at 03:57
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    It's probably not "officially" supported by VMware, but due to it's tight similarity to RHEL (which **is** a supported platform), you'll likely have no problems with it. – EEAA Sep 13 '11 at 03:58
  • And I really do enjoy having my mail server accessible no matter what the network conditions... Is it possible to access a client command line from a VMware host (without vSphere)? – Luke Sep 13 '11 at 03:59
  • Aha. OK. Thanks. And I only ask because I've had difficulties with LVM and CentOS before, but I'll hopefully be able to work them out. – Luke Sep 13 '11 at 04:00
  • Unfortunately no, the ESXi console is pretty bare-bones, and there is no way to access guest OS consoles through it. However, you *can* obviously get on the guest consoles using the vCenter client. – EEAA Sep 13 '11 at 04:02
  • ...that said, ESXi in and of itself is *very* stable, and in all my years of working with it, have never once had a situation where networking got so messed up (due to an ESXi bug) that I couldn't connect to the system via the vCenter client. – EEAA Sep 13 '11 at 04:05
  • I'm a huge fan of the free version of ESXi. I find it a fascinating idea to use it for just one server. – Luke Sep 13 '11 at 04:16
  • What are your thoughts on GhettoVCB in this situation? – Luke Sep 13 '11 at 04:16
  • I've never used it, so cannot comment other than that I've heard good things about it. – EEAA Sep 13 '11 at 04:17
  • I've actually virtualised CENTOS before and it all virtualised fine, though you do have to do some fiddling around with permissions on certain folders to get it to work, the best thing to do is to give it a try as if it doesn't work the old server will still be up and running. One thing you should be sure to check, though, is the network card configuration, I found that every time we added a new card (one with a new mac) it created eth1,2,3 etc, and some startup scripts relied on it for assigning IPs etc. Just be ready to fiddle to get it working, it won't be an instant switch over. – Alex Berry Sep 13 '11 at 12:40
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Swap the drive(s) into the 2950. This could require some raid magic and/or using mkinitrd

Build a new mail server from the working copy. Then use DNS to migrate from old to new. Or run two mail servers..

wrmine
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