Scott’s Blog

I’ve been getting questions in the comments on my blog about our Deltek Vision system now that it’s been in and in production for a while. Instead of answering them in the comments, I thought I’d do a new post.

First, I’ll describe what we’ve settled on for our hardware deployment. We run Vision completely virtualized on two different VMware platforms, in a three-server configuration. We have a SQL Server 2005 server running Windows 2003 Server Enterprise edition as a VM on VMWare ESX Server on a dedicated blade server. We have a Vision reporting server (Actuate) running Windows 2003 Server Standard edition on ESX Server on a blade server that is shared with other workloads. We have a Vision Web Tier server running Windows 2003 Server Standard edition on VMWare Server (the free server virtualization product) on a SuSE Linux Enterprise Server host that is shared with other workloads. All physical servers use shared storage in a fibre-channel SAN.

The reason we settled on ESX Server for SQL Server 2005 is that under load, we couldn’t get SQL to behave properly in VMware Server. We tried various different setups, different filesystems on the VMware Server host, and in every instance SQL Server behaved in a flaky unpredictable manner, failing in various ways.

The reason we settled on ESX Server for the reporting tier was because we wanted to have a second ESX Server to run the SQL Server VM on in case the first ESX Server died, so we needed it anyways. Otherwise the Vision Reporting tier runs fine in VMware Server.

The end user interface is provided by the web tier which is just an IIS server in VMware Server. It is plenty fast enough for us. We have about 600 users give or take a few. This server is pretty lightweight, all told, and we could probably get away with running the web tier and the reporting tier on the same box, but that would limit our expandability, and we’re growing fast.

All in all, everything has worked great for the last year. My caveats are that you want to strongly consider running SQL Server either in ESX Server or on bare iron. The rest of Vision, at least for a company of our size, works great virtualized on moderately powerful server gear (ours is a couple of years old already).

You don’t generally run into performance issues, unless your accounting people are running big batch jobs or you are running maintenance routines or backups. If you can run all that off-hours, then you can get away with smaller hardware than if you have to do stuff like that during the day. If you are small (a couple of hundred users) you could probably run on one box, but I would recommend server-grade gear, not repurposed desktops. SQL Server is finicky regarding disk I/O and you want to be sure you have a fast disk subsystem. I would also consider the Vision hardware recommendations to be minimums. We doubled the recommended RAM and processor speed and it has worked out well for us. Plus it gives us room to expand. We were under 400 users when we started this.