Number of Servers and OS maintenance

[detjo]

Q1: Whats the general opinion on VMs ..

a) To have as few VMs as poss and max out on roles per VM

b) To have as many VMs as the host can handle and install minimum roles per VM

 

 

Q2: How many hours per week (on average) do you guys spend on Server OS maintenance (and for how many servers)?

[fiza]

Q1 - Have many VMs and install minimum roles per VM.

Q2 - Depends what you mean - VMs are monitored using software. Touch wood - been running like clockwork for last 2 years.

[smithson83]

Q1 - I try and keep it to a single role per VM; DC(AD,DNS,DHCP etc)x2, File, App, Print, MIS, Web, Prxy, etc split over two hosts

Q2 - Other than updates done in hols, i have the server manager open on a second monitor but rarely touch it.

[cpjitservices]

managing VM's is NO different to managing a physical machine and the amount of VM's you have depends on what VM's you need and what your VM host/server can handle.

[Jamman960]

The whole point of VM's is to split the roles otherwise you might as well install everything on a single physical server directly which really isn't pretty - I still shudder thinking about how the server here was originally setup, AD, printers, file storage, sophos ent console, isa+smartfilter, exchange 2k3+puremessage, backup exec, whatever dodgy educational software we had at the time. It actually ran very well but I'd hate to have to recover that thing from backups or rebuild it from scratch.

 

We now have nearly everything down to 1 VM or physical host per role, I no longer have to worry about Exchange hogging all the ram or having to be VERY careful when chaning ISA rules or any other configuration for that matter

 

Server OS maintenance wise I think its much reduced due to everything being virtualised and separated out, I probably spend half an hour per week I guess. out of term time I might spend a little more on updates and general checkups but unless something causes an issue during term time I don't really have to touch the servers

Edited May 7, 2014 by Jamman960

[jaminben]

Do you all run your VM hosts on non domain servers or run them on the domain except for the DC's?

[fiza]

mine are on domain member servers.

[MordyT]

The whole point of VM's is to split the roles otherwise you might as well install everything on a single physical server directly which really isn't pretty -

 

 

Why not? If you VM host is powerful enough for running 30 VMs, then your server could easily run them all as one server.

 

It actually ran very well but I'd hate to have to recover that thing from backups or rebuild it from scratch.

 

 

There are such products that do... Image based backups and can do a bare metal restore of them. They can also do incremental backups in the 15 minute range and these backups can be used a VM environment if it all went to he**.

[jaminben]

mine are on domain member servers.

 

Ok, Thanks

[Roberto]

Why not? If you VM host is powerful enough for running 30 VMs, then your server could easily run them all as one server.

 

The server might have the capacity but there are good reasons besides that to separate roles out:

• Some roles do not play nicely together (e.g. installing Exchange on a DC is not a good idea).
  
• Installing multiple roles on one server means that required downtime to fix an issue or install a patch on one service means interrupting the other services.
  
• Makes it easier to manage DR: e.g. it's easier to test backups and practice DR for smaller, more focussed servers, you can prioritise which services are more important and recover those VMs first, etc.
  
• If the services are placed in lots of small VMs instead of one big server you can more easily expand available resources as requirements increase, by creating another virtual server host and moving some of your virtual server guests to the new host and increasing resource allocation for those specific items.
  

Edited May 19, 2014 by Roberto

[sonofsanta]

If you're going with VMWare or Hyper-V on Server 2012 hosts, you've no reason not to go the many-VMs-with-single-roles route, as you have memory deduplication and no longer have the overhead of running multiple OS instances.

 

That said, my hosts are 2008R2 and I still go the many-VMs route because it makes life easier. Maintenance/reboots/backups/DR, as others have said.

[Jamman960]

Why not? If you VM host is powerful enough for running 30 VMs, then your server could easily run them all as one server.

 

I agree a server capable of running 30 VM's would easily run them all as one server(assuming there are no conflicts) but as per my previous post it gets very messy - unless you document EVERYTHING you're going to have trouble keeping track of things and the smallest configuration change has the potential to upset functions other than the one it was intended for - especially with the amount of dodgy educational software we end up running server side for one reason or another.

 

There are such products that do... Image based backups and can do a bare metal restore of them. They can also do incremental backups in the 15 minute range and these backups can be used a VM environment if it all went to he**.

 

There are indeed but I'm not sure there were at the time, either way I'd much rather be able to recover a single VM and minimise the data loss/downtime instead of having to deal with data loss/downtime across all functions unnecessarily.

[Oaktech]

We are trying to go down the logical distribution of roles rather than blindly one server one role...

 

Our new domain is planned to have:

 

3 dcs, one physical, 2 VMs.

2 file server VMs on separate hosts running DFS.

1 application server.

1 multimedia server.

1 management server that runs start up/shutdown software / switch management / unifi management.

1 management server that runs VMware Vcenter and EMC software

2 replicated SQL servers on separate hosts.

1 Veeam backup server.

 

This is being achieved with 3 HP DL385 Gen8 diskless, 1x HP DL385 with 2TB internal for Veeam, 24TB of EMC VNX5100, 2x EMC Lenovo 16TB NAS.