J?rgen Keil wrote:
> Bart wrote:
>
>   
>> The more interesting question is
>> MB/sec from the dvd drive during the install.
>>     
>
> And note that in a lot of cases the MB/sec from the optical drive
> during the install is quite low, because hsfs issues 2k read
> requests to the drive, even when reading a multi-megabyte
> compressed package archive file.  AFAIK, file data on the iso9660
> installation media doesn't use sector interleaving, so hsfs could
> do a much better job here and read ahead data in bigger clusters.
>
> Test case:  watch "iostat -xnzc 5" while reading from an 
> optical media, using different block sizes:
>
> dd if=/dev/rdsk/c2t1d0p0 of=/dev/null bs=2k
> dd if=/dev/rdsk/c2t1d0p0 of=/dev/null bs=32k
>
> This SONY DVD RW AW-G170A (and a DVD-RW media)
> is reading ~3 MB/sec using 2k read requests, and ~8 MB/sec
> when using 32k reads.
>   

   My hsfs enhancements for Live Media fix this shortcoming of hsfs.
   It issues whole page reads where there is no interleaving and does
   re-ordering. So it can coalesce multiple pages into a single larger
   read.

   I sent out the changes for review on caiman-discuss sometime back.
   http://bugs.opensolaris.org/view_bug.do?bug_id=6588256
   
http://www.genunix.org/distributions/belenix_site//binfiles/hsfswebrev/index.htm

Regards,
Moinak.

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