Zack Reed - Design and Coding Blog


Remove Duplicates in Linux

I had run fdupes on our Marketing server at work and realized we had about 200GB of duplicates on a 700GB volume. Here is how I fixed it.


Encrypted External Drive

I wanted to extend my backup strategy to include rotating a couple encrypted disks offsite for another layer to backup my family videos and pictures. Here are the steps I used to do that on Ubuntu 12.04 Server.

mdadm replace smaller disks with larger ones 0

mdadm replace smaller disks with larger ones

I was recently asked on the Ubuntuforums how to replace (3) 1TB drives in an mdadm one at a time. Here’s a quick writeup of the process.


OS X delete all system emails

I recently had a cronjob that was sending me a bunch of useless emails. When I’d open my Mac’s Terminal, I was greeted by a "You have mail.", message (I feel like it’s the days of AOL). I wanted to delete all of these messages in one swoop, and it’s actually REALLY easy to do.


Increasing the size of mdadm RAID1 disks

Do you have a couple tiny disks in a RAID1 array in mdadm and want to upgrade them with newer or larger disks? Here’s how to do it. I did this test on Ubuntu 11.10.


Spin Down Idle Hard Disks

My home server uses mdadm software RAID for my media share. The array is made up of ten disks, so it only seemed natural to spin them down to save power when our family wasn’t home. Powering them off when they aren’t in use should also reduce the case temperature, hopefully increasing the lifetime of the hard disks.


mdadm auto-read-only

If you’ve used mdadm for a while, you may have come across a situation where your array’s status says auto-read-only. If you see this, there’s a very easy way to fix it.


mdadm RAID5 to RAID6 migration

mdadm makes raid management, even tasks that seem like they could be very complicated very easy. The following demonstrates setting up a (5) disk RAID5 array, and then migrating to a (10) disk RAID6 array.


HP Smart Array p410 Controller Tuning

We have a number of HP Servers at work, and I’ve been less than impressed with their slow throughput with stock parameters. One of our DL580’s has (10) 72GB 15K SAS drives attached to an HP Smart Array controller and could only do around 40 MB/s with the stock configuration. Here’s what I did to speed it up.