hdparm-8.6+ for the empeg (static binary)

Posted by: mlord

hdparm-8.6+ for the empeg (static binary) - 07/04/2008 12:55

Attached.

Note that is the very latest (prerelease) version of hdparm, and it may include functionality that the empeg kernel does not support -- such things will just fail with an error message.

Cheers

Posted by: mlord

Re: hdparm-8.6+ for the empeg (static binary) - 07/04/2008 13:24

Oh, and for the curious:

Code:

hdparm -t /dev/hda4

/dev/hda4:
 Timing buffered disk reads:   10 MB in  3.49 seconds =   2.87 MB/sec

That's our max read throughput for the empeg hard disk. Better than I'd imagined, actually.

Cheers

Posted by: peter

Re: hdparm-8.6+ for the empeg (static binary) - 07/04/2008 13:53

Originally Posted By: mlord

2.87 MB/sec [...] max read throughput for the empeg hard disk. Better than I'd imagined, actually.

It was a very long time ago that I measured the write throughput as 4MBytes/sec, so I can't remember how I did it, but it was probably something pretty extreme, e.g. mmap() in a foreground thread and msync() in one or more background threads. Does hdparm use read(), or mmap(), to obtain those numbers?

Peter

Posted by: mlord

Re: hdparm-8.6+ for the empeg (static binary) - 07/04/2008 23:20

Originally Posted By: peter

Does hdparm use read(), or mmap(), to obtain those numbers?

It's using read(2), so that it works on any device. No question that mmap() would be quicker, especially on slower hardware (such as the empeg).

And writes will be faster than reads, because both the kernel and the drive normally cache them.

Cheers