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vmware Archives - AWS Managed Services by Anchor

Ninja migrations from VMware to KVM using vmdksync

By | Technical | 2 Comments

We recently made the decision to pay off some of our technical debt by eliminating the VMware servers we built when we first started our Virtual Private Server (VPS) offering. VMware is a commercial vendor platform so it’s not exactly trivial to jump ship, but it is possible with some time and effort. Forcing a few hours downtime on our customers for business reasons is not cool, so we had to find a better way. Background and rationale When we first started offering virtual servers the software landscape was very different. After comparing what was available at the time we settled on VMware ESX for our virtual private server product – the right features, suitable for a VPS product, secure and manageable enough, sufficiently mature and reliable, and a nominal…

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VMware ESX Guest Disk IO

By | Technical | No Comments

Knowing the state of your disk IO latency in VMware ESX can help you pre-empt performance & capacity issues before the occur. There are a few guidelines you should keep in mind. These notes are directed towards people using directly attached storage. Write latency should be 0, because you have that fancy battery backed controller caching writes, right? Read latency should be under 8ms. Use the smallest stripe size possible for your RAID array setting. This helps keep random IO performance acceptable at the cost of some sequential performance. Do not virtualise very heavy random IO workloads on shared arrays, other guest VMs wont like you for it. Unless you have a very compelling reason not too, use RAID 10. Some other notes, specific to Linux guests are: Mount file…

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VMware announce the new VMware 4 named vSphere

By | Company News, Technical | No Comments

VMware have just announced that the new version of VMware ESX will be called vSphere. Some of the announced features are: 64bit kernel and console operating system (COS) clustered VirtualCenter Servers ESX hosts profile management cross-hosts virtual networking 8-way virtual SMP virtual machines fault tolerance across multiple hosts (the famous Continuous Availability presented last year) VMs and media library alarms on physical hardware faults access control on storage resources configuration change tracking full support for SATA local storage So it seems VMware are catching up to Xen with some of the features. There will be interesting times ahead in the virtualization space, with the recent release of Citrix XenServer for free. With an updated kernel and 64bit COS, end users should see more hardware end up on the compatible list…

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Firewalling VMware ESX for console access

By | Technical | No Comments

One of Anchor’s more recent product offerings is VMware-based virtual private servers. As one of my colleagues has already detailed, we take extra measures to secure the VMware host server to reduce the possibility of a compromise. Our VPS offering uses VMware ESX, which runs on bare metal and doesn’t have a host operating system. This isn’t the full story – according to documentation it boots a Redhat Enterprise Linux 3 system, then loads the vmkernel which is where the real work is done. One of the nice things about this approach is that there’s a userspace environment in which to run support software, like good monitoring components. We ran into an odd problem recently with an ESX host server on a dedicated network segment, namely that we couldn’t view…

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VPS – Virtual Private Servers now available

By | Company News, Technical | No Comments

After dabbling with a variety of different virtualisation technologies over the last 2 years we’ve launched a Virtual Private Server (or VPS) offering based on VMware ESX server. We’ve chosen ESX server for a number of reasons not to mention the ability to perform a sufficient level of monitoring on the host system and have the virtual machines behave in just about every respect the same as a traditional dedicated server would. A VPS can offer a more affordable step between shared web hosting and dedicated servers but it also creates a more flexible hosting environment. Additional resources can be added to a server with as little effort as a reboot, and they can be added rapidly (hours vs days) in the event that increased performance is needed at short…

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