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I'm not shopping as much as I'm looking for some guidance on good idea / bad idea strategies. I'm sure I'm not in the "best practices" budget range.

Currently, I have 3 dell poweredges running xenserver in a pool.

Each node has a ubuntu file server, serving about 6TB. One is the primary, the other two are rsync targets for backup. The 6TB is stored on their respective local storage disks as an LVM of 3x2tb virtual disks. The fileserver VM disks are also stored on the node local disks.

Each node also runs a smattering of light-weight VMs for web, development, windows VMs, and stuff like that. Several of those VM's disks reside on a QNAP NAS to play with live migration. These VM's are often clients of the primary file server (like all the mail, web content, user files are stored on the file server, not on the mail, web, and samba VMs).

This all works fine, and is a major step up for us. The downside is that the QNAP is a single point of failure. And the only thing the QNAP is doing is serving migratable VM images, not client data. Someday the poweredge local arrays will be full, and we will have to reinvent ourselves again.

Is it wise to have heavywieght vms (like the fileserver, with its 6+ TB disks) on a SAN or NAS?

Would it be better to keep the VMs lightweight, have the VM images on a SAN or NAS, and use 2 or more NAS act as NFS-serving file appliances? A hybrid SAN/NAS that can serve iscsi for images and NFS for the client vms?

It seems like live-magration would be a misnomer if you have to migrate a fileserver with its entire 6+ TB disk.

I recognize there are plenty of ways to skin the cat. We've already skinned it a few ways. What makes sense?

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closed as not constructive by Ward, mdpc, longneck, HopelessN00b, Michael Hampton Nov 17 '12 at 22:51

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It seems the Qnap can not do active/passive failover currently. To eliminate this SPOF there are really 2 ways you can go.

  1. The "Enterprise" way. Buy a NetApp, EMC Cluster or something in this spirit. Move all your storage to these devices and have an active/passive or active/active cluster set up. You could also do this with appliances like TrueNAS or Nexentastor which will save you a lot of $$$ investment.

  2. The D.I.Y. way. This can be done with any Linux, BSD or Solaris(/fork). Move all your data to a box you build, and set up with software such as DRBD (file storage clustering suite) and Heartbeat. (software like OpenFiler can do this for you aswell).

Seeing as you seem to be looking for a budget solution, I would go for option 2. Buy 2 nice boxes, install FreeBSD, set up a ZFS pool and cluster the boxes. This would eliminate all your need for local storage as you can run everything off NFS/iSCSI and will give you a nice backup in the form of a active/passive cluster. Throw the qnap on ebay. or use that as storage for your backup solution (hard drive backup on a separate machine)

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Great answer. I'd group TrueNAS, NexentaStor and the other options like FreeNAS, OpenE, etc down with #2 and openfiler though. You can buy prebuilt appliances for many or build it yourself using some servers. Regarding whether you should run "heavyweight" VMs on a SAN/NAS, if it is properly designed, absolutely you can do this. I'd take a close look at NetApp. It is pricier than option 2 but may give you a better upgrade path to support growth and will give you great flexibility on how you use it (SAN/NAS). You may also want to consider how important support is, as option 2 may be limited. – x50 Nov 16 '12 at 14:56
TrueNAS and Nexentastor are the commercial counterparts for the OSS products (Freenas/Nexenta) there are other companies like this. but these 2 I know, they are Enterprise providers in the way they deliver the appliances and give support on those just like NetApp or EMC for example, thats why they are listed under 1. Could have gone with 3 lists, where TrueNas and Nexentastor would be middle-tier – Flash Nov 16 '12 at 15:25
Thanks for the clarification. I knew of TrueNAS but not their enterprise support option. NexentaStor I've typically seen more associated with the "Community" edition of Nexenta, but I do know vendors like Pogo are selling appliances with it preloaded. I fully agree with your answer though, I think those are the best options. – x50 Nov 16 '12 at 19:30

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