Tag Archives: benchmark

Fill an LVM volume group completely with a single logical volume

I learned a cool LVM trick today – how to resize a logical volume to use a certain percentage of a volume group.  Since I just have one logical volume in the group, I did the following:

[root@nyu ~]# lvextend -l +100%FREE /dev/diclonius/vector
  Extending logical volume vector to 7.28 TiB
  Logical volume vector successfully resized

Thanks Redhat Documentation!

In other news, I ran a performance test on my 5-drive RAID-5 using HD204UI drives from Samsung:

[root@nyu tmp]# dd if=/dev/zero of=foo count=5 bs=$((1024*1024*1024))
5+0 records in
5+0 records out
5368709120 bytes (5.4 GB) copied, 18.1434 s, 296 MB/s
[root@nyu tmp]# dd if=foo of=/dev/null                         
10485760+0 records in
10485760+0 records out
5368709120 bytes (5.4 GB) copied, 15.2682 s, 352 MB/s

So, 350MB/sec reads and 296MB/sec writes! Not bad!!

Giganews vs. Astraweb

Recently, I’ve been a bit low on money thanks to 2-3 expensive hobbies I’ve picked up. So, I took a look at my bills, and remembered I was spending $30 per month on usenet. Well, that’s too much, but high-speed unlimited usenet providers with 200 day + retention and SSL are hard to find. Then, I noticed that Astraweb is moving to 270+ retention soon, making the $11/month worth it (almost 1/3 of the cost of Giganews). Currently, they still only have 170 days, but hopefully the upgrade will kick in soon. The monthly price of the plan stays as long as you keep it even though it’s a special that may expire soon. The question is, how’s the performance?

The Setup

Though their web interface isn’t nearly as polished as Giganews, why would you need polished for usenet? I decided on Star Wreck Legacy, which is a free and legal collection of films.

Filename Size Number of Files Percent Uploaded Age Group
starwrecklegacy.par2 6.6 GB 135 102.4 132.0d a.b.dvd

It’s a hefty 6.6GB, so it should eliminate any short-term bursting, etc. that may skew measurements. It even has an overabundance of par2 files. Nice…

I use stunnel to create SSL tunnels to the secure news servers, and connect to the unencrypted news port on my local machine that stunnel provides. This tricks hellanzb, my client, into thinking it’s just using a regular news server, while all my traffic just looks like normal SSL traffic, indifferentiable from normal secure web traffic save the ports. Both the tests will be conducted with the SSL on using 18 connections.

I have relatively high bandwidth for this country (20Mbits Down, 8Mbits up), but it’s from Comcast, so we’ll see how that holds up. It’s currently working pretty well consistently. Here’s a recent test I did at Speedtest.net:


Transferred 5957.2MB in 49m 43s at 2044.5KB/s (starwrecklegacy.par2)


Transferred 5958.6MB in 49m 45s at 2043.5KB/s (starwrecklegacy.par2)


So, as you can see above, there’s no significant difference between the speed of the 2 services. Yet, Astraweb is massively cheaper. Get it cheap while you can!