Cheap Virtual Private Servers (VPS)

E. Frank Ball III

www.FrankB.us

NBLUG - North Bay Linux Users Group

Types of servers

• Home Server (DSL or Cable modem)
• Leased Server
• Co-Located Server (Co-Lo)
• VPS - Virtual Private Server

Home Server

• DSL or Cable modem
  • Cost: Electric bill for server.
  • Lots of storage - 1TB drive for $50.
  • Slow internet connection.
  • Usually stuck with DHCP.
  • $20/month for Static IP from Sonic.net.
  • Terms of service and/or firewalls can prevent servers.

Co-Located or Leased server

• Leased Servers
  • Expensive: $60/month and up.
• Co-Location
  • Even more expensive.
  • Co-Lo's may require buying a quarter rack.
  • Responsible for hardware.
    • Purchase
    • Delivery
    • Maintenance

VPS

• VPS - Virtual Private Server
  • Cheap: $10/year and up.
  • New business model - market is changing rapidly.
  • Lots of companies being bought out, or going out of business.
  • Cost of entry is low, so more inexperienced business owners.
  • Cheap: $10/year and up.

Virtualization Technologies

• Xen
  • Para-virtualization.
  • Intermediate cost.
• KVM (Kernel-based Virtual Machine)
  • Full virtualization - Hardware assisted.
  • Newest type of virtualization, not many vendors offering it yet.
  • Most expensive.
• OpenVZ

Virtualization Technologies

• OpenVZ
  • Not true virtualization: Containers.
  • Highest effeciency.
  • Single shared kernel for all VPSs on host.
  • Can NOT load kernel modules.
  • tun/tap interface not usually enabled (no tunneling: VPN, 6to4).
  • All processes from every server is visible, and killable, on host.
  • Root on host has full access to virtual machine.
  • Cheapest option.

OpenVZ resource control limits

• /proc/user_beancounters
  • Maximum RAM usage
  • Maximum Kernel memory usage
  • Maximum number of processes and kernel-level threads
  • Maximum number of TCP/UDP sockets
  • TCP/UDP input/output buffers
  • Number of CPUs
  • % of CPU usage
  • Maximum disk space
  • Number of open files
  • Number of file locks
  • Number of pseudo-terminals
  • and many more ...
  • Most vendors only limit RAM, CPUs

Be efficient

• Running a server with 128MB of RAM
  • OpenVZ + sshd, cron, syslog-ng = 6MB RAM
  • replace rsyslog with syslog-ng - 30MB RAM (or inetutils-syslogd)
  • nsd instead of bind
  • thttpd, nginx, or lighttpd instead of apache
  • postfix MTA instead of sendmail
  • each ssh login uses about 4MB RAM -
    dropbear is more efficent (about 1MB), but is missing sftp
  • 60MB of RAM for full server (web, dns, mail)
  • No GUIs.
  • My setup script configures my VM in minutes.

Cheap VPS Providers

Links for more information

• Finding a server:
  • LowEndBox.com
  • WebHostingTalk VPS Offers
  • LowEndStock.com
  • DoesBuyvmHaveStock.com
  • Low cost hosting
• Discussion Forums:
  • LowEndTalk.com
  • WebHostingTalk VPS Forum

More information

• OpenVZ inforomation
  • OpenVZ on Wikipedia
  • OpenVZ Wiki
    • /proc/user_beancounters
• Setting up a server
• proxy tunnel: ssh -x -p 22 -fND 2222 my.server.net