New technologies, new toys — Oh how I love getting my hands dirty with them. Today I am going to have a look at ATA Over Ethernet (AoE) as an alternative solution to NFS in the role of a NAS/SAN implementation. We will look at both the server side vblade setup and the client side AoE kernel module along with a practical deployment setup which includes a convenience script I developed to make vbladed slightly less of a nuisance to maintain.
It used to be all the talk, everyone knew it, accepted it but few did anything about it and still even today, very few do anything about it. What is it? Data Integrity. But it is not in the form of how we usually look at data integrity; it is not backups, raid management or similar — it is host based intrusion detection.
What is host based intrusion detection (hIDS)? In it simplest form it is basically the monitoring of a file system for added, deleted or modified content, for the purpose of intrusion detection and (post) compromise forensic analysis. At More >
In today’s hosting environment it is common place for servers to have hardware based raid cards but what is not common place is having a reliable method for checking the status of the raid arrays. Few would question the value to data integrity by making use of raid technology but very few organizations and businesses implement the tools required to proactively maintain raid arrays, they simply hope for a DC tech to hear a raid alarm and assume the technician will handle the failure. The reality is very different, data centers are loud and increasingly server-dense so hearing a raid More >
Recently I started to tackle a load problem on one of my personal sites, the issue was that of a poorly written but exceedingly MySQL heavy application and the load it would induce on the SQL server when 400-500 people were hammering the site at once. Further compounding this was Apache’s horrible ability to gracefully handle excessive requests on object heavy pages (i.e: images). This left me with a site that was almost unusable during peak hours — or worse — would crash the MySQL server and take Apache with it by frenzied F5ing from users.
I went through all the More >
Anyone who has ever used SSH key-pairs to access more than a couple of servers (or hundreds in my case), will tell you they are an invaluable convenience. It is a natural progression and very common usage that SSH key-pairs are coupled with other common tasks or tools, where having a pass phrase attached to the key would be counter-intuitive to the task automation. So, what do we do despite our better judgment? We create key-pairs with absolutely no pass phrase. The implications are abundantly obvious, if the private key ever gets lost or stolen, any accounts that have the More >
Traditionally, the dist upgrade path that many were familiar with from the RH8/9->Fedora or similarly Fedora dist upgrades, have applied more or less to RHEL/CentOS but with the release of 4.5 and early releases of 5.0 the actual dist upgrade path was messy or nearly impossible. The early versions of 5.0 (up to 5.2) had excessive dependency issues with versions later than 4.4 for straight dist upgrades that would often result in a box blowing up on you or forcing a messy downgrade attempt of 4.5+ to 4.4 to try get things to dist upgrade. With more recent release updates More >