Re: [00/17] Large Blocksize Support V3

David Chinner
2007-04-27T17:34:59Z

On Sat, Apr 28, 2007 at 02:36:20AM +1000, David Chinner wrote:
> The test was writing a single 50GB file to a fresh filesystem, and
> then reading it back. Run on two different dm stripes - a 4-disk
> RAID) and a 8disk RAID0 stripe, with a stripe unit of 512k. Disks
> are 10krpm SAS, external jbod on PCI-X good for ~850MB/s read and
> ~750MB/s write. Server is 4p intel x86_64 with 16GB RAM.
>
> READ WRITE
> blksz disks tput sys tput sys
> ----- ----- ----- ---- ----- ----
> 4k 4 332 35s 203 76s
> 64k 4 173 20s 273 21s
> 4k 8 403 35s 443 76s
> 64k 8 634 21s 540 21s
>
> Throughput in MB/s.

Some more information - stripe unit on the dm raid0 is 512k.
I have not attempted to increase I/O sizes at all yet - these test are
just demonstrating efficiency improvements in the filesystem.

These numbers for 32GB files.

READ WRITE
disks blksz tput sys tput sys
----- ----- ----- ---- ----- ----
1 4k 89 18s 57 44s
1 16k 46 13s 67 18s
1 64k 75 12s 68 12s
2 4k 179 20s 114 43s
2 16k 55 13s 132 18s
2 64k 126 12s 126 12s
4 4k 350 20s 214 43s
4 16k 350 14s 264 19s
4 64k 176 11s 266 12s
8 4k 415 21s 446 41s
8 16k 655 13s 518 19s
8 64k 664 12s 552 12s
12 4k 413 20s 633 33s
12 16k 736 14s 741 19s
12 64k 836 12s 743 12s

Throughput in MB/s.

Consistent improvement across the write results, first time
I've hit the limits of the PCI-X bus with a single buffered
I/O thread doing either reads or writes.

Cheers,

Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group