27 Sep 08 Linux Benchmark, IO statistics and system statistics with dstat

There are a number of common command line tools that we can use to monitor system resources. We have df for disk space, free for RAM usage, top for processes, bmon for network usage, etc. Quite often though, I find it useful to monitor them all simultaneously, and constantly switching commands or using ‘watch’ with free/df is annoying.

I came across dstat recently that gives a nice colorful overview of a choice of statistics. Here are some useful command line options from the man page:

You can also output to CSV with –csv and disable color with –nocolor.
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Tags: bandwidth usage, bmon, df, disk space, dstat, free, io statistics, linux benchmark, linux statistics, monitor, network usage, process, processes, RAM usage, system statistics, top

02 Jul 08 Bandwidth Limiting HOWTO with linux, tc and iproute2

I’ve recently optimized the scripts used for bandwidth management in one of our UK facilities and I thought I’d post a quick howto on it.

Discuss this page here

My setup here is a live feed entering eth0 on this linux router and leaving eth1 into a switch connected to a collection of other servers. This is set up as an unrestricted public router, routing between a /30 on eth0 and a /24 on eth1.
Note: We can’t in any way restrict the amount of traffic that eth0 receives from the outside, so instead we restrict how fast eth0 sends data out, the same applies the other way round. So, if we want to limit the amount of data that the local servers can send, we shape the router’s external interface (eth0). If we want to limit the amount of data that the local servers can receive, we shape the router’s internal interface (eth1)
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Tags: 100mbit, 10mbit, 95th percential, 95th percentile, Add new tag, apt-get, bandwidth management, bmon, bulk, classes, datacenter, debian, external interface, htb, interactive, internal interface, iproute2, Linux, percentile, priority, qdisc, restrict traffic, router, routing, switch, tc, traffic shaping