I just returned from a month long vacation in Europe. My wife and I took a budget (hostels and Easy Jet) tour of Europe starting in Ireland, and moving through Sweden, Norway, Denmark, Holland, Germany, and England. The trip was a blast, but I’m still glad to be back home. You can see pictures of our trip on Jen’s Picasa album.
While on the trip, I decided to spend more time maintaining this blog. We will see how strong my resolve to do so really is in the next few months. However, since I am paying for the blog, I may as well make more regular use of it. In addition, I think the writing could prove to be therapeutic.
I recently added a new hard drive to my desktop and reorganized the partition structure. In doing so I wanted my /home partition to be mirrored for safety, but I also wanted to use lvm to make managing my multiple partitions less painful. In my research, I found there are basically two ways to do this. One is to create a linux RAID1 device from the two drives and then use that device as a physical extent in a lvm volume group (here is a basic tutorial). The other method is to us LVM2′s mirroring capabilities. I personally would rather use the latter solution if there is no performance impact since moving the partitions around later would be much easier, however what I read gave the impression that LVM2 mirroring would be slower.
To test this, I setup a quick informal benchmark. I created 2 partitions on each of two drives and set one up as plain raid1 (no lvm) and the other as lvm with a mirror. I then ran bonnie++ on each of the partitions. The results were surprising. MD RAID1 gave about 25MB/sec write and 50MB/sec read. However LVM2 mirrored gave about 50MB/sec write and 55MB/sec read. Since the test was not perfectly sterile (there were other processes running at the same time) I would be willing to give these number +/- 10MB/sec. However still, LVM write was considerably faster than MD RAID1. I so far have no explanation for this, but will test further. If anyone has an explanation, I’d be happy to hear.
I mean really, of all the juvenile things…
I just thought I’d announce that today, one of the projects I’ve been working on recently went live. Yo Journal is an online personal journal that allows you to keep track of daily entries, categorize those entries, and also keep track of specific types of data like weight, movies, and books. To read more about Yo Journal, you should visit the about page, or the tour. There is a free edition as well as an expanded version for pay that adds features like file uploads and categories.