ZFS in the trenches
Ben Rockwood is awesome. If you haven't had a chance to check out his blog, its a must read for any Solaris Admin. He gave a presentation at the Open Storage Summit about ZFS. (Video Here) Its worth the read / view for some indepth ZFS concepts…
$ read more →Monitoring interrupt activity on Linux hosts
While transferring a slew of data to one of my Linux boxes a few weeks back, I was curious how many interrupts were being generated each second. To answer my question, I installed the itop utility. Itop displays the number of interrupts per second that occur per device, and provides output similar to top. Here is a sample run: This is a useful tool, and one I want to remember for the future!
$ read more →Monitoring pipe activity with pv
While perusing the catonmat blog, I came across a reference to the pv utility. Pv allows you to monitor the amount of data that is written to a pipe, which is incredibly useful for monitoring how much data is transferred between pipe endpoints. The following example shows this super useful tool in action: When pv is added to the pipeline, you get a continuous display of the amount of data that is being transferred between two pipe endpoints. I really dig this utility, and I am stoked that I found the catonmat website…
$ read more →Bash tips
I read through the bash tips on the hacktux website, which brought to light the fact that you can do basic integer math in your bash scripts. This is easily accomplished by using dual parenthesis similar to this: This is good stuff, and I need to replace some old and statements with this.
$ read more →Tracing block I/O operations on Linux hosts with blktrace
I've been spending a bunch of time with Linux lately, and have found some really nifty tools to help me better manage the systems I support. One of these tools is blktrace, which allows you to view block I/O operations to the devices connected to your system. To see just how useful this utility is, I present to you with the following example: As you can see from the above output, each I/O is printed along with a summary of the operations and how they were processed by the I/O scheduler. This is super information, which can be used to figure out I/O patterns (random reads, random writes, etc.), the size of the I/O operations hitting physical devices in a system and the type of workload on a system…
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