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vps Archives - AWS Managed Services by Anchor

Bugfixing KVM live migration

By | Technical | 2 Comments

Here at Anchor we really love our virtualization. Our virtualization platform of choice, KVM, lets us provide a variety of different VPS products to meet our customers’ requirements. Our KVM hosting platform has evolved considerably over the six years it’s been in operation, and we’re always looking at ways we can improve it. One important aspect of this process of continual improvement, and one I am heavily involved in, is the testing of software upgrades before they are rolled out. This post describes a recent problem encountered during this testing, the analysis that led to discovering its cause, and how we have fixed it. Strap yourself in, this might get technical.

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Shiny new hardware: Dell R720xd

By | Technical | No Comments

We just received a shipment from Dell, it’s our new VPS hardware! Even the once-mighty leviathan is feeling rather humble these days. She’s got a pair of hyperthreaded octo-core Xeons (32 logical cores, rawr!), 384GiB RAM and 15.6TB of bare disk capacity! Team that with a pair of 10Gbps network ports, a pair of 1Gbps ports, H710 RAID card and the latest iDRAC 7 for management (much improved over the iDRAC 6), and you’ve got one hell of a machine. Unlike most of our servers, which come in pairs, this one was received as a single unit. Once our usual burn-in process has been done (expected to take quite a while), it’ll be evaluated for suitability as a replacement for the R510 chassis model that we currently use for VPS…

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A crash course in Ceph, a distributed replicated clustered filesystem

By | Technical | 3 Comments

We’ve been looking at Ceph recently, it’s basically a fault-tolerant distributed clustered filesystem. If it works, that’s like a nirvana for shared storage: you have many servers, each one pitches in a few disks, and the there’s a filesystem that sits on top that visible to all servers in the cluster. If a disk fails, that’s okay too. Those are really cool features, but it turns out that Ceph is really more than just that. To borrow a phrase, Ceph is like an onion – it’s got layers. The filesystem on top is nifty, but the coolest bits are below the surface. If Ceph proves to be solid enough for use, we’ll need to train our sysadmins all about Ceph. That means pretty diagrams and explanations, which we thought would…

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Signups open for beta test of Anchor’s US presence

By | Company News, Technical | No Comments

Good news, everyone! Anchor’s US hosting infrastructure is ready for business. We’re not so brazen/naïve as to think that it’s perfect, but we’re pretty damned confident that it’s ready to go. This is where you come in. Starting in the first week of December, we want to give you a free VPS for three months and see how you like it. We want you to use it, a lot, and we’re not charging for anything – not for the server, not for the bandwidth, nothing. It’s the legendary Anchor products and service, for free. The server comes sans-management, so you’ve got root and are welcome to run whatever you like on them. If this sounds like your idea of fun, APPLY ONLINE NOW to let us know you’d like to…

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Anchor to build a US Point of Presence

By | Company News, Technical | One Comment

It’s not really any big secret that we’ve gradually been doing more and more work throughout North America. Nor should it really come as any surprise that we’ve been around doing this web hosting thing for quite a while now and are always looking at ways that we can improve our offerings to our valued customers. On this basis, we’ve recently made the decision to commence a build-out of a US-based facility to offer an alternative point of presence based on the west coast of America. What was the motivation behind this? Over the past 2 years we’ve had the absolute privilege and pleasure of building and delivering various complex hosting environments in facilities other than our primary point of presence in Sydney, Australia. There obvious ones include Github, Stocktwits,…

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Why you should use LVM: part 1319755409 in an infinite series

By | Technical | One Comment

At anchor, we loves us some LVM. It makes managing storage a breeze. Now, we’ve got one more reason to love it. Because now we have lvmsync. Like most modern hosting companies, we run a lot of VPSes, and sometimes the chunk of storage they’re on isn’t where it needs to be, so we have to transfer it around. Ordinarily, this would involve a lengthy period of downtime while dd did it’s business and sent the whole LV across a network. NOT ANY MORE! Now, with the magic of lvmsync we can transfer the bulk of the data while the VM is running, and then do a quick transfer of just the changes after we shut the VM down. We think our customers will appreciate the reduction in downtime, and…

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Awesome but often unknown Linux commands and tools

By | Technical | 5 Comments

I’ve been working in this industry for a while now and naturally spend a lot of time using Linux on a daily basis. This gives lots of exposure to various Linux commands and tools. That said, I am sometimes surprised when I see, often very experienced system administrators, using somewhat convoluted commands to do something relatively simple using a different tool. This is my opportunity to share some of these experiences: 1. pgrep and pkill – The first command ‘pgrep’ will return the process id based on a name or other attributes. pkill will signal a process with a matching name or attribute. Want to kill all processes being run by a given user? Issue a pkill -U USERNAME; sure beats the hell out of: ps -U USERNAME | awk…

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Why A “Dedicated” Support Technician Is A Bad Idea

By | Company News, Technical | No Comments

An emerging trend nowadays is that a lot of businesses have trouble differentiating themselves from their competitors. At this point they usually need to innovate, so they have a “novel” product to sell, or change the way they do business to make themselves more appealing to customers (of course another option is to start slashing prices in an attempt to soak up some of the market, but this simply isn’t sustainable, making it a risky gamble). Anchor is no exception to this – we firmly believe that our success is in no small part thanks to our quality of customer support and technical prowess. One suggestion that often arises when discussing how we can Do It Better is somehow building better relationships with our customers. The better we understand their…

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Reduce Linux VPS/VM guest memory usage

By | Technical | 3 Comments

Reducing the memory usage in your VPS/VM can be a great way to free up some resources to handle more requests, users or some other metric of win. By default at Anchor we provision our Red Hat & Cent OS VPS servers with a trim memory usage profile by disabling a lot of unneeded services at install time. We do this by using Trogdor (our hardware/software burninator) and Puppet. So just what services do we disable, if they exist on the new VPS? gpm netfs pcmcia sgi_fam yum-updatesd pcscd rhnsd xfs hald hcid or sdpd hpiod or hpssd.py dbus-daemon cupsd You can also reap performance gains by changing how you serve content. For example you can use a cut down high performance web server (nginx or lighttpd) to serve all…

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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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