On Saturday, 30 October 1999 at 6:14:32 +0200, [EMAIL PROTECTED] wrote:
>> Because Vinum is being maintained, and because Vinum will allow you to
>> stripe your disks instead of simple concatenate them, which will probably
>> result in better I/O rates.
>
> Some simple measurements shows ccd to be slightly faster when striping
> 11 disks, then running 130 threads reading 1MB blocks from random
> sector-aligned positions in a 10 GB file.
>
> with Vinum: 70 MB/s (2 of the 11 subdisks shown in iostat output)
>
>
> tty da5 da6 cpu
> tin tout KB/t tps MB/s KB/t tps MB/s us ni sy in id
> 0 94 171.82 36 5.96 174.53 38 6.48 0 0 16 3 80
> 0 35 173.90 36 6.13 174.79 36 6.10 0 0 9 3 88
> 1 47 175.33 35 6.01 173.96 38 6.44 0 0 9 3 88
> 1 378 175.69 38 6.53 170.85 38 6.28 0 0 9 3 88
> 1 37 176.47 37 6.42 173.21 35 5.87 0 0 9 3 88
> 0 36 176.05 39 6.72 172.27 35 5.87 0 0 9 3 87
> 0 36 168.95 40 6.60 172.89 36 6.14 0 0 9 4 87
> 0 36 169.44 39 6.42 171.73 38 6.30 0 0 8 4 88
> 0 36 172.64 37 6.24 174.79 38 6.44 0 0 9 3 88
>
> With ccd: 80 MB/s
>
> tty ccd1 cpu
> tin tout KB/t tps MB/s us ni sy in id
> 0 39 204.46 408 81.56 0 0 5 1 94
> 0 39 205.28 413 82.75 0 0 5 1 94
> 0 39 204.91 438 87.72 0 0 7 1 92
> 0 39 204.96 429 85.96 0 0 6 1 93
> 0 39 205.13 439 87.85 0 0 6 1 93
> 0 39 204.80 448 89.61 0 0 5 1 94
> 0 39 204.77 428 85.66 0 0 5 1 94
> 0 39 204.66 440 87.95 0 0 6 1 93
> 0 39 205.58 421 84.61 0 0 5 1 94
What program did you use to get this information? I'm surprised by
the size of the transfers, which is larger than MAXPHYS (128 kB, the
largest physical transfer allowed). There's also a discrepancy
between the transfer size for Vinum and ccd which almost exactly
corresponds to the measured performance.
It would be interesting to see the output of rawio (in the Ports
Collection) on these two volumes.
> ccd is also capable of striping disks with different sizes.
Correct. That's one aspect I didn't consider worth doing in Vinum.
Greg
--
Finger [EMAIL PROTECTED] for PGP public key
See complete headers for address and phone numbers
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message
