Stop Letting Disk I/O Strangle Your Throughput
It is 3:00 AM. Your Nagios alerts are screaming. Your load average is spiking to 20.0, but your CPU usage is idling at 5%. If this sounds familiar, you aren't suffering from a traffic spike; you are suffering from the most common bottleneck in the 2011 hosting landscape: I/O Wait.
For years, we relied on spinning platters—7,200 RPM SATA drives or, if you had the budget, 15k SAS drives in a RAID 10 array. But as web applications become more read/write intensive (thanks to heavier CMS platforms like Magento and dynamic caching layers), mechanical physics simply cannot keep up. The "Cloud" buzzword is everywhere this year, but few understand that abstracting storage doesn't make it faster. In fact, on poorly managed platforms, network-attached storage adds latency that kills transactional databases.
The "Noisy Neighbor" Phenomenon
Most budget VPS providers in Europe are still stuffing hundreds of customers onto single OpenVZ hardware nodes with standard SATA backplanes. When one user decides to run a heavy backup or a complex MySQL query, the disk heads start thrashing. Everyone else on that node waits. Your application hangs.
As a Systems Architect, I rely on iostat to diagnose this. If your %iowait is consistently above 10%, your storage solution is inadequate.
$ iostat -x 1
avg-cpu: %user %nice %system %iowait %steal %idle
4.50 0.00 1.20 25.30 0.00 69.00
See that 25.30%? That is the sound of your server choking on slow storage.
The Solution: SSD Caching and True Isolation
We are seeing a paradigm shift this year. Solid State Drives (SSDs) are finally becoming viable for enterprise caching layers. While purely SSD-based hosting is still prohibitively expensive for mass storage, hybrid setups using SSDs for caching hot data (like ZFS L2ARC or hardware controller caching) are changing the game.
However, hardware is only half the battle. Virtualization technology matters. At CoolVDS, we prioritize KVM and Xen HVM over container-based virtualization. Why? Because true hardware virtualization provides better resource isolation. When you have a defined block device, the hypervisor can better guarantee your I/O throughput compared to a shared file system.
Optimizing Your File System for Speed
Even on high-performance infrastructure, default Linux configurations are often too conservative. If you are running CentOS 5 or 6, stop using the defaults. Here is a quick win for your /etc/fstab: enable noatime.
By default, Linux writes a timestamp every time a file is read. For a high-traffic web server, this turns every read operation into a write operation. Madness.
# Edit /etc/fstab
/dev/sda1 / ext4 defaults,noatime,barrier=0 1 1
Pro Tip: If you are running a dedicated MySQL server, consider formatting your data partition with XFS instead of ext4. In our benchmarks at CoolVDS, XFS handles parallel I/O requests significantly better on large datasets.
Data Sovereignty: The Norwegian Advantage
Performance is critical, but so is legal stability. With the rise of cloud computing, many realize too late that their data is sitting on a server in a jurisdiction with questionable privacy practices. The US Patriot Act allows US authorities to access data stored by American companies, regardless of where the server is physically located.
For Norwegian businesses, and indeed any European entity handling sensitive customer data, this is a massive risk. Hosting within Norway isn't just about getting 2ms latency to the NIX (Norwegian Internet Exchange) in Oslo—though that speed is undeniable. It is about compliance with the Personal Data Act (Personopplysningsloven) and satisfying the Datatilsynet (Data Inspectorate).
When you deploy on CoolVDS, your data stays on chassis owned by us, in data centers physically located in Norway. No third-party clouds, no cross-border replication unless you configure it.
Conclusion: Demand Dedicated Throughput
In 2011, you shouldn't have to accept "best effort" storage performance. If your provider cannot tell you what kind of RAID controller they use or whether they oversell their disk I/O, it is time to migrate.
We built CoolVDS for the pragmatic professional who values raw metrics over marketing fluff. We use enterprise-grade hardware RAID 10 arrays and strictly limit the number of tenants per node to ensure your iowait stays at zero.
Is your current host slowing you down? Deploy a high-performance KVM instance on CoolVDS today and see the difference a proper storage backend makes.