Linux

Optimal RAID Stripe Size and filesystem Readahead for RAID-10?

What RAID stripe size is ideal for an array of hard drives? What are the default settings for both raid stripe size and filesystem readahead? Are those defaults acceptable? How do these settings impact the performance of my server? In this post, we’ll go into detail as to what settings are ideal for a server

IOWAIT in Linux — is iowait too high?

High IOWAIT can be a real problem in linux, making your server grind to a halt. The question is, how high is too high? When should I be concerned? Firstly, we’ll talk about what IOWAIT means, discuss related statistics and how to interpret them, and finally how to decide if IOWAIT is causing a problem.

Check One, Two, Three!

Avoiding Workplace Complacency and Customer Inconvenience through the use of Checklists. Here at IOFlood we pride ourselves on using the right tools for the job, in everything we do.  We love servers, which is why we would never use substandard hardware during provisioning.  We also love our customers, which is why we take pride in

What is Apache Keepalive Timeout? How to optimize this critical setting.

If you’ve struggled to fix web server slowdowns or crashes, you may have come across a setting for Apache called “Keep-Alive”. This is one of the most powerful — and frequently misused — features of apache. In this article, we’ll explain: What is Apache Keepalive / Keepalive Timeout? What configuration is optimal for best server

IPv4 Address Subnetting Explained

Every server at IOFlood comes standard with one /29 worth of IPv4 IP addresses.  Additional IP’s can be added at an extra cost, up to a total of one single /24 (or equivalent) worth of IPv4 addresses per server.   But how many IP’s do you really get with a /29 or a /24? In this

Connecting to an IOFlood VPN via PPTP on Archlinux

We love servers, and we love our customers! Our customers are the ones we do this for, so it’s always a great thing for us when we get positive feedback from our customers, we know we’re doing things right. Recently one of our customers reached out to us and shared with us a blog entry

IOFLOOD.com – Phoenix, AZ, Dedicated Servers: 2019 Carrier Upgrades and Network Improvements

Updated: You can read about our 2020 network upgrades here: https://ioflood.com/blog/2020/08/07/ioflood-com-phoenix-az-dedicated-servers-2020-carrier-upgrades-and-network-improvements/ IOFLOOD.com is proud to announce that we’ve completed a series of upgrades to our network to maximize performance and reliability for our dedicated server customers. To improve performance and reliability, all top of rack switches have been replaced with upgraded Juniper switches. These new

Adding AHCI support to CentOS after it was already installed in IDE mode

Sometimes when you’re using a server, you’ll notice that the disk i/o is slower than it ought to be, or is using a lot more cpu than it should be during disk i/o. In some cases, this would be because the BIOS is configured to use your sata drives in legacy IDE mode instead of

Setting up Software RAID / MDADM status alert Emails for failed drives in Centos, Ubuntu, and Debian

Issues regarding software and hardware raid are no stranger to the IOFlood blog, with articles discussing the relative merits of each, articles discussing why raid is important (and so are backups), and so on. But RAID only provides protection against failed drives if you realize a drive has failed and replace it. Often times, a

How to set up source nat routing (SNAT) in iptables to load balance outbound connections across multiple IP addresses

In our earlier days, before IOFlood, some of us ran web based proxy services. These were popular at workplaces or schools for accessing websites that were blocked there, such as gmail and myspace (remember myspace?). One common problem that came up, was that with so many users each sharing one IP on one server, our