Welcome to Part 4 of our se [...]
Welcome to Part 4 of our series of blog posts on RAID – Redundant Array of Inexpensive Disks. In this post, we’ll be going through the performance benchmarks we’ve performed using both Hardware RAID and ZFS Software RAID.
Since our entire platform uses SAS Host Bus Adapters and ZFS RAID, rather than using Hardware RAID cards, we’ve split the tests into two sections. The first section covers a fair comparison between HW RAID 5 and 10 plus ZFS RAID 5 and 10 on a Dell Perc H310 HW RAID card. The second tests covers a range of ZFS RAID tests on an LSI 9207-8i SAS HBA, and includes some additional ZFS RAID types (such as RAIDZ2 (RAID6) and Hybrid SSD accelerated pools). [Read more...]
Welcome to Part 3 of our series of blog posts on RAID – Redundant Array of Inexpensive Disks. In this post, we’ll be talking about Hardware RAID cards, as well as Host Bus Adapters, and finally Software RAID such as via ZFS.[Read more...]
Welcome to Part 2 of our series of blog posts on RAID – Redundant Array of Inexpensive Disks. In this post, we’ll be talking about the different RAID levels available, which are basically the different ways RAID can lay out your data on disk to improve performance and/or reliability.
There are a bafflingly large number of RAID levels available, and we won’t cover all of them. You can get a full breakdown on Wikipedia. Here are the main ones:[Read more...]
Back in 2008 we wrote a tiny blog article about RAID 1 vs RAID 5 performance. This turned out, rather bizarrely, to be one of our most popular blog articles. We’ve been doing a lot with storage over the past few years, so we decided to write a series of blog posts on RAID.
In this series we’ll cover:
RAID is a method of providing data security and/or improving performance by distributing data across multiple disks. There are different methods of doing this, aka "RAID levels", the most common of which are mirroring (RAID 1) and striping with parity (RAID 5), although there are others too – we’ll cover the common ones below.
RAID is typically performed by a PCIe RAID controller card, to which the disks will be directly attached. However it’s possible to do RAID in software, and most operating systems support this. Indeed, some modern filesystems such as ZFS actually prefer to do the RAID themselves, as it affords greater control over the data, and this is how we do RAID at EveryCity.
RAID should at least protect you against a single drive failure, and other RAID levels (Such as RAID 6 or RAID 10) can protect against multiple drive failures. When a failed disk is replaced, the array should automatically rebuild, although during this operation performance may be reduced.[Read more...]
“Uploadr is a simple way for everybody to do something they’ve needed a programmer for until now: upload files to any website. It works for all the document, audio and video files people use in their daily life, and it works on any site. Follow Uploadr on twitter @uploaderio“
EveryCity are proud to be sponsoring Launch48, an event held this weekend where young entrepreneurs get together to pitch, build and launch a startup business.
EveryCity will be providing free hosting, as well as advice and support for the attendees.[Read more...]
In this blog post (and the next) I’m going to look at a couple of the biggest challenges facing hosting providers in these days of fast bandwidth, cheap storage, ‘viral’ social media and seemingly infinite ‘cloud’ capacity, namely:
These two topics often get lumped together as one, but they are distinct and do present different problems.
When dealing with issues around scalability, the challenge can be coping with an exponentially growing web site, which may mean that user numbers keep doubling every few months. However, the upside in this scenario is that growth can be reasonably predictable and capacity can be planned reasonably well.
When dealing with burstability, however, the opposite is often true: traffic may be low and manageable most of the time. The downside is that it may massively spike in an unpredictable way from time to time.
I’m going to tackle burstability in my next post. For now though, I’d like to look at scalability.
The first graph below represents a typical high growth site in terms of numbers of users. As you can see, it approaches quite an aggressive exponential curve.[Read more...]
At EveryCity, we’re looking forward to the forthcoming mashupevent, Being-Open – http://beingopen.org/. EveryCity has been a sponsor of mashup* events for a couple of years now and they’re always very informative, good fun and a great opportunity to network.
This one should appeal to product managers, service architects, creatives, development managers, software engineers, entrepreneurs and investors. It’s a half-day event exploring new cost effective ways of approaching product development and service delivery using open platforms, open data and open development – a subject close to our hearts, and our very own Alasdair Lumsden will be on one of the panels.[Read more...]
You should not be penalised in other countries but search engines may feel that your pages are more relevant for the UK than other countries depending on a number of settings and rules. Search engines estimate how the website is relevant for a particular country and they determine it by the following factors:
EveryCity is supporting OpenIndiana, a derivative of the open-source operating system OpenSolaris, which was launched in London on Tuesday, 14th September 2010, to an enthusiastic response. So far there have been well over 2000 downloads of the OpenIndiana ISO.
As you may know, we run a public cloud based on Solaris technology.
The OpenIndiana ‘spork’ was developed in response to signals increasingly pointing to a withdrawal of support for OpenSolaris, following Oracle’s takeover of Sun Microsystems.
OpenIndiana is available for immediate download. It is a drop-in replacement for the official Oracle OpenSolaris distribution, which it will track in a way similar to the CentOS/RHEL relationship. It aims to provide 6 monthly stable releases with bug and security fixes, as well as twice-monthly development builds.