Basic Postmark Test on Btrfs code on kernel 3.17-r3

I ran a basic postmark today and the results are below for the btrfs code on a Seagate Constellation drive I have for testing. If any of the the btrfs developers read the kernel newbies list, please send me a list of tests with docs on how to run them on this drive ,I don't care about killing it :) and also since it's an enterprise drive, you can test enterprise tests if wanted.
Nick
Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:
11 seconds total
10 seconds of transactions (10000 per second)

Files:

	50516 created (4592 per second)
		Creation alone: 500 files (500 per second)
		Mixed with transactions: 50016 files (5001 per second)
	49827 read (4982 per second)
	49581 appended (4958 per second)
	50516 deleted (4592 per second)
		Deletion alone: 532 files (532 per second)
		Mixed with transactions: 49984 files (4998 per second)

Data:

	301.18 megabytes read (27.38 megabytes per second)
	304.49 megabytes written (27.68 megabytes per second)

I'm curious if many here know the difference between a consumer drive and a enterprise drive.

Obviously a lot of enterprise drives have higher performance and quality specs, but the biggest difference is how they treat media errors.

A consumer driver is targeted at standalone use, an enterprise drive is targeted at raid array use.

Thus when a consumer drive hits a media error the firmware is setup to re-read that sector repeatedly before it gives up and returns an error to the OS.

An enterprise drive's firmware on the other hand is setup to be in a fail fast mode. The idea is from a system perspective it should be better to have the drive return an error immediately upon a media error and let the system get the data via raid-redundancy. That also means the raid system has more granular knowledge of what's going on with the drive and can rewrite valid data as an example to that bad sector. A rewrite can trigger an internal sector reallocation from the spare list.

The key thing to note is that in general an enterprise drive is a bad choice for standalone use. The firmware is just setup wrong.

I've forgotten if hdparm can be used to switch between the two operating modes.

Greg

Sent from my Android phone with K-9 Mail. Please excuse my brevity.