Testing Linux hard drive speed

Today I got a battery for the cache on my my HP P410 raid controller.

After getting the battery charged, I thought it could be fun to see how fast it could actually write to the raid. And then it hit me… I never actually tested it without the write cache, because without the battery, it is not safe to enable write cache.

So sadly there is no comparison of before and after, but the numbers I got, are still some I am very happy about.

To test the speed, I used this command

dd if=/dev/zero of=/store/speed.img bs=8k count=256k

which writes to /store/speed.img, which is located on my raid.

262144+0 records in
262144+0 records out
2147483648 byte (2,1 GB) copied, 4,0029 seconds, 536 MB/s

And holy cow, 536 MB/s?! That is way more than I had ever hoped for with this setup.

The server is a little HP MicroServer N54L with 4gb memory. 4x 4tb WD Red, attached to the HP P410 raid controller, in a RAID5 configuration. On the P410 there is a 512MB cache module and backup battery for the cache.

I am not complaining!

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