The Myth of "Guaranteed" Resources: Why Your VPS Feels Slow
It is 3:00 AM. Your Nagios pager goes off. The load average on your database server just spiked to 50.0. You SSH in, run top, and see... nothing. Your processes are idle. Yet, the system is crawling.
If this sounds familiar, you are likely the victim of a "noisy neighbor" on a container-based VPS (like OpenVZ or Virtuozzo). In the budget hosting market, providers often cram hundreds of containers onto a single physical server, gambling that not everyone will use their resources at once. When they do, your performance tanks.
At CoolVDS, we reject this model. As of 2009, the Linux kernel (2.6.20+) has matured enough to make KVM (Kernel-based Virtual Machine) the superior choice for production environments. Here is why true hardware virtualization is the only path forward for serious systems administrators.
The Architecture: Shared Kernel vs. True Hypervisor
To understand the lag, you have to look at the kernel.
OpenVZ/Virtuozzo: You share the host's kernel. If another customer on the same physical box triggers a kernel panic or exhausts the dentry cache, your server goes down with them. You also cannot modify kernel modules or tune sysctl.conf significantly.
KVM (Used by CoolVDS): KVM turns the Linux kernel into a hypervisor. It leverages Intel VT-x and AMD-V hardware extensions. Every Virtual Machine (VM) gets its own isolated kernel, its own memory space, and acts like a dedicated server.
How to check if your hardware supports KVM
Before you deploy, verify your CPU flags. If you are building a test lab in Oslo or deploying to our rack, run this:
egrep -c '(vmx|svm)' /proc/cpuinfo
If the result is 0, you are stuck with software emulation. If it is 1 or higher, you are ready for hardware acceleration.
Performance Tuning: The VirtIO Advantage
Critics of full virtualization often point to the overhead of emulating hardware. "It's slower than native!" they argue. In 2009, that argument is dying thanks to VirtIO.
VirtIO allows the guest OS to know it is virtualized and cooperate with the hypervisor for I/O operations, bypassing the expensive emulation layer. This drastically reduces latency for disk and network operations.
Pro Tip: When setting up KVM on CentOS 5.3 or Ubuntu 8.04 LTS, always ensure you are using thevirtio_netandvirtio_blkdrivers. Without them, you are emulating an ancient Realtek network card and IDE disk, capping your throughput unnecessarily.
Comparison: Throughput Stability
| Feature | OpenVZ (Containers) | KVM (CoolVDS) |
|---|---|---|
| Kernel Access | Shared (Restricted) | Dedicated (Full Control) |
| Memory Allocation | Burstable (Oversold) | Hard Reserved |
| Swap Management | Non-existent / Fake | Real Swap Partition |
| I/O Latency | Unpredictable | Consistent |
The Storage Bottleneck: Why We Use RAID-10
Virtualization is useless if the disk subsystem crawls. Many providers in Norway are still running single SATA drives. When twenty clients try to write logs simultaneously, the disk heads thrash, and 'I/O Wait' skyrockets.
For CoolVDS, we utilize 15k RPM SAS drives in Hardware RAID-10. We are also beginning to roll out Enterprise SSDs (Solid State Drives) for high-performance database clusters. SSD technology is expensive right now, but for a MySQL master server handling thousands of queries per second, the random read/write speeds are unbeatable compared to spinning rust.
Data Sovereignty: The Norwegian Advantage
Latency isn't just about disk speed; it's about physics. If your target audience is in Oslo, Bergen, or Trondheim, hosting in a German or US datacenter adds 30-100ms of round-trip time.
Connecting via the NIX (Norwegian Internet Exchange) ensures your packets stay local. Furthermore, hosting within Norway ensures compliance with the Personopplysningsloven (Personal Data Act). The Datatilsynet is becoming increasingly strict about where sensitive data resides. With CoolVDS, your data stays on Norwegian soil, protected by our strong privacy laws, not subject to the whims of foreign surveillance.
Deploying for Resilience
Don't just take our word for it. Test the difference. Run a compile benchmark or a database stress test like sysbench.
If you need root access, a custom kernel for specialized firewall rules (iptables modules), or just guaranteed RAM that doesn't vanish when your neighbor gets slashdotted, you need KVM.
Ready to ditch the lag? Deploy a high-performance KVM instance with CoolVDS today and get true root access in under 60 seconds.