Time to upgrade the server

August 22, 2006 9:35 AM

I want to upgrade my linux server and run all of my services inside a VMWare instance, am I nuts?

It's getting time to upgrade my linux server and would like some feedback on the two major changes I'm considering.

Right now I'm running two hard drives in a RAID-1 configuration, I'm considering installing the new setup with three drives in a RAID-5 + LVM configuration. This seems to be a nice balance between reliability, cost, and future expansion.

The other big change I'm considering is running a thin linux installation with RAID5+LVM and networking and then have my actual server software running inside a VMWare instance. Two reasons, one I can create the instance on another box and slowly migrate services from the old server to the new instance while keeping both running and secondly, I can easily backup the entire vm image or move it to another box in the event of hardware failure.

I'm not heavily loading the box, the additional overhead of VMWare shouldn't be an issue.

Is this crazy? Any serious flaws I'm not thinking of?

posted by beowulf573 to computers & internet (7 comments total)

Not crazy. That's pretty much why virtual servers are used, and it sounds like you've taken into account the VMware overhead.
posted by Blazecock Pileon at 9:42 AM on August 22, 2006

Sounds like an excellent idea to me. One suggestion: consider keeping your storage on a different box and mounting it remotely. That way your vmware image can be smaller and you can very quickly chuck it onto a new machine(s) if you have a hardware failure or need more powah.
posted by Skorgu at 9:56 AM on August 22, 2006

you might also consider using xen (see also) -- not quite so easy to set up as vmware, but has some amazing features.

e.g. you can actually push an entire running server instance, while it's running, from one xen dom0 server to another. spooky, I know.

also, paravirtualization a la xen will generally be more resource-efficient than what vmware does.
posted by dorian at 9:59 AM on August 22, 2006

I have been using VMWare for a while and had almost no problems. Just be aware that VMWare is a dog when it comes to disk performance. I would recommend not putting something like a backup server, Exchange, or anything that is extremely IO intensive in VMWare, or utilize a SAN.

YMMV
posted by SirStan at 10:14 AM on August 22, 2006

Thanks for the feedback. I've considered Xen, but the lack of Windows host support and rumors of instability have given me second thoughts. I am going to give it a spin before I decided.

My current plan is to keep all large data (music, video, mail, etc) on the host system and access in the virtualized system via a network share, probably samba. I like the idea of a separate NAS box but don't want to have yet another box running. I've already got too many.
posted by beowulf573 at 11:05 AM on August 22, 2006

If you're even remotely considering springing for new hardware, new chips from AMD and Intel (Pacifica and VT-i respectively) let you run Windows inside Xen. I have zero experience with xen but it sounds nice.

VMWare ESX/VMotion/Enterprise/whatever they call it today also lets you migrate running instances but I suspect that a legal acquisition of said software may be a bit out of your budget. Not that that is likely to stop anyone :)

Really though, I suspect you'll save yourself a lot of headaches by having your data on a different physical machine. Its so liberating to be able to format and start over without having to agonize over whether you really did type hda and not hdb.

Your samba idea is right on target though, then if you want to move to a NAS later you can. Also, ignore VMware's shared folder system, it's completely broken.
posted by Skorgu at 12:38 PM on August 22, 2006

You really, really should think about using FreeBSD or Solaris, & using jails or zones. The Solaris Zones implementation is better orchestrated for services (it interfaces with their services management system directly, iirc) and much of the system is built with the idea that there will be many zones present (ie, utilities know & have options for dealing with the zones). VMWare really seems like overkill for this, let alone Xen.
posted by devilsbrigade at 12:58 PM on August 22, 2006