Home > Support > HOWTO List > VPS setup on dedicated servers (and why it is a brilliant idea)

Why run a VPS on your dedicated server

Recently we have seen a number of people wanting to 'upsize' an existing VPS.  They wanted more memory, more disk space, or more CPU, or less CPU contention with other users.

These users also wanted to keep the convenience of the VPS setup: e.g. not having to worry about kernel compiles, having the ability to easily run full file system backups, do control panel restarts, do easy distro reinstalls or upgrades, and getting console access to their server.

And/or they wanted the migration from their current VPS to a dedicated server to be as simple as a DNS change.

In these cases we have been setting up the users on a dedicated server with their server running as a VPS.

Other users wanted to run multiple VPSs, and for these users we have been setting up a dedicated server for them and letting them run multiple VPS' on it.  This can cost less than running multiple regular VPSs with us.

The dedicated server with VPS setup

If you order a dedicated server, then we can set it up as a VPS host (it is an option on the dedicated server ordering pages).

You can opt to run either with a single VPS or with as many VPSs as will reasonably fit on the server you select (given that server's memory and disk, etc).

When setup as VPS host you will get:

The virtualization software we use, Xen, has very low overhead.  So a single VPS running on your dedicated server will be only 3-5% slower than a regular, non-virtualized server.

Disk IO on the VPSs may not be as fast as 'raw' disk access.  So the VPS setup may not be appropriate for very active database servers where very fast response times are required.

RimuHosting will retain exclusive root access to VPS hosting environment (aka dom0) so we can best manage it.

Note you will need to have at least an IP per VPS you intend to run, and one extra for the dom0 server.

After we setup the dedicated server itself for you (which normally takes 1-3 days) we will contact you about what VPSs to setup (and what hostnames, memory sizes, disk sizes, etc, to use).

File system sizes

You may order a dedicated server with, say, 120GB of space.  Do you make your VPS file system(s) use up all that space? Or do you just size it according to what you need?

We recommend you have the smallest VPS size that is comfortable for you.


How much space do backups take?

By default we take weekly snapshots of your file system image.  And try to keep two generations of that.  i.e. you'd be using 3 x your file system size.

We store the snapshots we take on your dedicated server's disks.  We recommend these are setup as RAID1 to protect your data.  If you order 4 disks on your dedicated server then we can store the main file system on one RAID1 array and the backups on the other RAID1 array, which provides even more protection.  In addition to our backups we recommend you keep a recent backup of your key data and config files on a remote server.  For example, our backupsapce server.

If you are running low on space we can set it so we keep just the one backup generation (so you need 2 x your file system size of free space).

If you request it we can disable the backups.  In which case your VPSs can use all the available space, however if you accidentally delete a file or make a mistake somewhere you would need to rely on your own backups.

Want lots of disk space?  Want the / file system to be backed up?  But cannot afford the downtime for all the data to be backed up?  Then we can create a separate (non-backed up) disk image.  We mount this on your VPS.  Its data is not backed up.  If you need the data to be backed up you can use another method, e.g. our off-server backupspace ftp service.

Increasing a VPS disk image size

If you need to increase the size at all at any point just use the resource change tool.  It is quick and easy to increase disk sizes as you need it (reductions are a bit slower).

Memory sizes

The VPS setup we use has a dom0/management domain.  This uses between 400 and 600MB of memory.  The former if you have just one or two VPS', the later if you have many.

The remainder of the server's memory is left over to the VPS (or VPSs) that you want to run.

If you are using just a single VPS on the dedicated server, we would normally set the one VPS to use all the available memory.  (There is no such thing as having too much memory).

If you are running multiple VPS' then just let us know how much each VPS should be allocated.

We can easily shuffle memory between VPS' later on (adding or reducing memory).  It just requires a quick VPS restart.