Troubleshooting

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

Making sense of Linux memory usage, Part 1: how to read “top” in CentOS.

We get this question a lot, about “Why is my Linux server using so much ram?”. In many cases, it really isn’t using much ram at all, but just to be sure we always have to check. At least half the time, really very little is being used, but the way that Linux reports ram

nf_conntrack: table full, dropping packet — A solution for CentOS Dedicated Servers

A common problem you may experience is sluggish performance or disconnections from your Centos dedicated server, even though there is sufficient CPU, ram, disk i/o, etc. After some troubleshooting, you may come to believe you are being DDoS attacked, but you don’t see an unusual amount of traffic, and there’s no single IP or handful

Troubleshooting backup problems with Idera R1soft under Centos (part 1)

Everyone knows it’s a good idea to keep backups, but it can be difficult to get them up and running, and even harder to keep them staying that way. On top of that, the backup process can make your server slow to a crawl if you have typical hard drives instead of SSDs. R1Soft is a

Troubleshooting high linecard CPU use / exhaustion on Brocade MLX and MLXe routers

Today we’re going to be talking about a poor design decision in the Brocade MLX and MLXe series routers that can lead to CPU exhaustion on your router line cards. Overall we’re very happy with the Brocade MLX. After all, every routing platform has its quirks, so one small problem that is easily solved is

Dell C6100 BMC / IPMI Mac address all zeros after update? 00:00:00:00:00:00 — Script fix solution

Some of you may have noticed the Dell C6100 on ebay for a pretty cheap price. 4 servers in a single 2u chassis for as little as $800. Great deal right? I had a lot of trouble getting the IPMI / BMC firmware updated on these in the first place. After getting it upgraded, the

Real world performance of Brocade Foundry FESX-448-PREM — CPU exhaustion

In case you’re still using the Brocade / Foundry FESX-448-PREM for doing routing on your network, I thought I would share some of the performance limitations we’ve seen on that platform. We’ve long since upgraded our network to use newer and more powerful Brocade MLX routers, but wanted to share our experience so others could

e1000e NIC link failure / x9scm / x9scl / patch fix for Centos

If you’ve had problems with the nic driver failing on x9 / x10 supermicro motherboards with the intel e1000e NIC, we have a fix for you. Centos 6 on X9 motherboards (x9scl / x9scm) seems to have the most problems, but other motherboards and OS’s are potentially affected as well. There are a lot of

How to Edit Ram Allocation on a Xen VPS under Solusvm When SolusVM Won’t Update Configuration File

Hi Everyone, If you’re like me, you’ve had problems in the past with SolusVM running Xen, and some of them can be a little irritating and difficult to track down. There’s one particularly confusing problem whose solution I would like to share with you today. Who is affected? Anyone who wants to change the amount