Burning-in hard drives tests

[MartynW]

1) Individual sequential read and write tests. This is basically just using "dd if=/dev/da${n} of=/dev/null bs=1048576" to do a read test, and "dd if=/dev/zero of=/dev/da${n} bs=1048576" to do a write test. Note the reported read/write speeds at the end and compare them to both the other drives in the pool and also any benchmark stats you can find for that particular drive on the Internet. They should be very close.

Thanks for this great article. Can I please clarify a couple of points regarding this?

1. "dd if=/dev/da${n} of=/dev/null bs=1048576". Does this go on forever? I had to ctrl-C after 3.5 hours. If I add count=1K on this, it response in 7 seconds. The drives are 4TB Seagate NAS drives.
2. Using count=1K, I get quite a range of read rates, 144-155MB/s would that be expected? I can't find any stats on the internet?
3. If these test do take a while, with 6 disks to test, would you do 6 at once? I also assume that you would need one terminal sessions per disk, read and write? So 12 running at the same time?

 

[jgreco]

1) No. It goes on for the size of the disk. Which you absolutely want to do.

2) Within expected range. Get rid of the count=1K and they'll probably come in with a percent or two of each other.

3) Yes, do them all at once. You want your system to be very resilient and nothing you should be able to devise ought to knock it out.

 

[joelmusicman]

3) Yes, do them all at once. You want your system to be very resilient and nothing you should be able to devise ought to knock it out.

Does that include baseball bats, axes, and blowtorches?

 

[jgreco]

Sure, if you buy your drives from ioSafe :)