There is lots of gotcha's, depends on what path you want to take :) Citrix's XenServer offering would do what you want but it's not GPL (but it does have some upsides). Otherwise Xen would do it no worries. If you haven't played with many offerings then XenServer might be a better option, it's a bit more user friendly than Xen (in my opinion that is). But I know Xen and XenServer can run CentOS and 2K3 with no major hassle. You can even automatically virtualise the physical boxes with XenServer once you have some hosting setup for the VMs which makes setup easier.
Couple that with FreeNAS/Openfiler for an iSCSI backend and you'd be set. You'd want gig ethernet between the server and storage, but switches are cheap these days. If you need them, server level NICs (ie ones that match HCLs) can be had for $150 or less. Regarding replication. you need to consider if it will be constantly active (ie always syncing), or snaphots every X hours, or however else you want. Of course that would still mean you'd need to have a handle on how much data that would be and go from there. We've gone down a similar path at work so I will happily share any thoughts you want to hear or questions you have. On 13 May 2010 10:52, Nigel Allen <[email protected]> wrote: > Greetings > > I need to formulate a DRP for a customer and thought that I would ask the > slug for it's collective wisdom. > > Customer currently has 3 x HP rackmounted servers runnning Centos 4.8 and a > Dell rachmounted server running Windows Server 2003. > > Backups are currently done to tape every night using Amanda. > > Given the nature of the business and the reliance it places on computer > availability, we're looking at replication and virtualization a a first step > and off-site replication of some sort as step two. > > First thought was to max out the memory on two of the servers, one for > normal running and one as a hot or warm standby, and the virtualize all of > the servers onto the two machines. An external consultant has already > suggested doing this with VMware, installing the ESXi hypervisor on the two > main servers and installing a NAS shared between the two systems (hot and > cold) so that if the hot server fails, we can simply switch over to the cold > server using the images from the NAS. > > Couple of things concern me about this approach. The first is using VMWare > rather than a GPL solution. The second is where we would install the NAS. > Physically, the office space is all under one roof but half the building has > concrete floors and half has wooden. (The hot server is in the wooden "main" > office, while the cold server was to go in the concrete floor area. There is > also a firewall (a real one) in between the two areas). > > Questions: > > 1) Can anyone offer any gotcha's, regardless of how obvious they may seem > to you? > > 2) Is there a GPL solution that fit's this scenario? Even if it's not a > bare metal hypervisor and needs an O/S. Remember it has to virtuaize both > Server 2003 and CentOS > > 3) What's the minimum connection we would need between the NSA and and the > two servers sharing it? > > 4) What kind of speed/bandwidth should we be looking at for the off-site > replication. > > I'll happily take anything else anyone would like to throw at this - > suggestions, reading matter etc - it's not an area of great expertise for us > having only paddled around the edges with Virtualbox. > > TIA > > Nigel. > > -- > SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ > Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html > -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
