My ramblings on the stuff that holds it all together
Category Archives: Networking
The following screen dump is from an HP DL380G5 server that runs all the core infrastructure under VMWare Server (the free one) for a friend’s company which I admin sometimes.
It is housed in some co-lo space and runs the average range of Windows servers used by a small but global business, Exchange SQL, Windows 2003 Terminal Services.
As a result of some planned (but not very well communicated!) power maintenance the whole building lost power earlier today, when it was restored I grabbed the following screenshot as the 15 or so Virtual Machines automatically booted.
interesting to note that all the VM’s had been configured to auto-start with the guest OS, meaning there wasn’t any manual intervention required, even though it was a totally dirty shutdown for both the host and guest OS’es (No UPS, as the building and suite is supposed to have redundant power feeds to each rack – in this instance the planned maintenance was on the building wiring so required taking down all power feeds for a 5 yearly inspection..)
There are no startup delay settings in the free version of VMWare Server so they all start at the same time, interesting to note the following points..
The blue line that makes a rapid drop is the pages/second counter, and the 2nd big drop (green) is the disk queue length. the hilighted (white) line is the overall %CPU time, note the sample frequency was 15 seconds on this perfmon.
After it had settled down, I took the following screenshot, it hardly breaks a sweat during its working day. there are usually 10-15 concurrent users on this system from around the world (access provisioned via an SSL VPN device) and a pretty heavily used Exchange mail system.
The box is an HP DL380 G5 with 2 x quad core CPUs (8 cores in total) and 16Gb of RAM, it has 8 x 146Gb 15k HDDs in a single RAID 5 set + hot-spare, it was purchased in early 2007 and cost c.£8,000 (UK Prices)
It runs Windows 2003 Enterprise Edition x64 edition with VMWare Server 1.0.2 (yes, its an old build.. but if it ain’t broke..) and they have purchased multiple w2k3 ent-edition licences to take advantage of the virtualisation use-rights to cover the installed virtual OS’es.
It’s been in-place for a year and hardly ever has to be touched, its rock-solidly available and the company have noticed several marked improvements since they P2V’d their old servers onto this platform, as follows;
- No hardware failures – moving from lots of low-end servers (Dell) and desktops to a single box (10:1 consolidation)
- The DL380 has good redundancy built in, but it’s also backed up with a h/w maintenence contract, and they also have a spare cold-standby server to resume service from backups if data is lost.
- Less noise, the old servers were dotted around their old offices in corners, racks etc – this is the main thing they liked!
- Simple access anywhere – using a Juniper SA2000 SSL VPN, its easy to get secure access from anywhere
- Less reliance on physical offices and cheap DSL-grade data communications, now the servers are hosted on the end of a reliable, data centre class network link with an SLA to back it up. if an individual office looses its ADSL connection, no real issue – people pick up their laptop(s) and work from home/starbucks etc.
- Good comms are cheaper in data centres than in your branch offices (usually)
Hopefully this goes to show the free version of VMWare’s server products can work almost as well if budget is a big concern, ESX would definitely give some better features and make backup easier, they are considering upgrading and combining with something like Veeam Backup to handle failover/backup.
Useful (if starting from an unrelated point) blog post on how companies deploy BGP – for people who don’t normally need to know this kind of stuff – I see a fair few organisations use it for providing network/carrier resilience at the network edge.
Detailed networking isn’t my field but you always need to know enough to get by and bring in the experts when you are out of your depth or doing something complicated.
Have been playing with a few new widgets, and I figured out how to add HTML code into the pages that wordpress.com hosts.
If you need to do it – just add a “Text” widget and then you can put any HTML code you like in that and it gets processed as part of the page load.
I’ve also added Feedburner for my RSS feeds, I’ve seen a big spike in traffic to my blog over the last week
I’m trying to figure out where it is coming from… the default wordpress.com stats (where this site is hosted) don’t really go into much more detail than number of hits; and it doesn’t seem to tally up with the search-engine results or click referrals – so maybe that will shed some light on it.
Otherwise pop a comment on this post and let me know what you find interesting and I’ll try to tailor some content around your needs, the How to deploy a virtual machine from a template seems to be the most popular post so far.