lxc_and_virtualization_pros_and_cons

Advantages and disadvantages of virtualization and LXC

LXC sounds great, running multiple separated linuxes is a great thing (from a security point of view, and ease of maintenance If you someday discover your mailserver-vm is not working You might run into all kinds of problems AND LIMITATIONS. Yes: limitations, because there are some things that won't run correctly on lxc (yet).

Advantages:

  • Easier maintenance and backup of individual virtual machines than one 'big' linux server
  • Running different 'servers' on one physical computer saves hardware and power costs
  • Security separation, hardware access from inside a vm may be restricted.

Disadvantages:

  • Speed issues if too many vm's are using the same hardware at the same time (especially hard drive access, recommend a SSD).
  • If hardware breaks, all virtual machines machines are affected.
  • More machines to administrate/monitor/update (now you've got to update/patch/secure more 'computers' than if everything would have been installed on a single server).
  • Might have problems accessing hardware, as access to that hardware might be restricted (?)
  • By design, can't install NFS server (in kernel mode) in a container.
  • Can't use pcap/trafshow/ettercap/.. traffic display utilities (?) (experienced myself, but yet to confirm).
  • All logs are shared (?) (still have to test out how much this is true, and how it can be changed).

Alternatives to lxc

Wikipedia: Comparison of (platform) virtual machines (lxc, KVM, OpenVZ, and many more)

If I find lxc to be unfit/unsuitable for my purpose, I will have a look at KVM (Kernel-based Virtual Machine), though it will require other hardware.. Another site that lists a few of them is the Debian system virtualization portal. /*

*/

Decisions on hard & software

Even before starting installing the lxc software, there are some important(?) decisions to make:

  • Buy a SSD to lower hdd access time to speed things up [link] (12-12-2010: Just bought me a OCX Vertex 2 60GB review 1 2!)
  • what filesystem to use, for snapshotting & data deduplication [link], hard links? Wikipedia: Comparison of file systems
  • Buying a computer with a cpu supporting virtualization (Intel VT-x, VT-d, and the AMD counterparts […]) (LXC can however do fine without the virtualization technologies found in newer cpu's)

/* will lxc use these technologies or is it just for KVM?

todo: links to other sites, full- vs. para-virtualization; kvm vs lxc vs xen vs vmware vs virtualbox */

SSD

Link


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lxc_and_virtualization_pros_and_cons.txt · Last modified: 2017/01/19 00:50 (external edit)

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