Casper.Dik at sun.com wrote:
>> Note that the package install is just under 2/3 of the total;
>> the SMF manifest import is an obvious target. There are also
>> pauses of a minute or two in the configuration phase that I
>> don't understand.
>
> Perhaps those are the "uncompress java/X" bits?
>
>> The limiting factor in current installs appears to be the cpu
>> required to bzcat the archives. It took the test machine 2 minutes
>> to unpack the staroffice archive - going at 2M/s which is the
>> network data rate I observed during install. That's about 1/6 of
>> the total data - so 12 minutes of the 22 is bzcat. That's the
>> lowest hanging fruit. Even when you've solved that there's still
>> 10 minutes left - and only 4 of those appear to be down to the
>> contents file. There is of course the actual time it takes to write
>> the data to disk - and, being scattered around in small files,
>> those writes won't be as efficient as the contents file.
>
> I think it isn't too difficult to bunzip2 on the server and then
> gzip then and see how that makes a difference.
>
>> So, for this test, of the total 36 minutes the contents file rewrite
>> is about 20% of the package installation time and 10% of the total
>> elapsed time. The impact on a DVD install is even less - there it's
>> even more important to stream the data adequately fast.
>
> Ah, but if the content file holds up data reads then speeding it
> up may have ripple effects.
>
>> Even so, the contents file is costing us 4 minutes, and once you
>> solve the uncompress problem and the SMF import it starts to look
>> like the next target. But even there it's only going to be 1/3 of
>> the time at most, and there are a couple of ways to speed things
>> up:
>> - re-order package installation to install small packages first
>> - install clusters rather than individual packages
>
As I've noted earlier, there are three related parts to improving
install from DVD performance:
1) fixing the slow uncompress (eg switch to gzip or equiv)
2) removing the contents file rewrite so that the target disk doesn't
get IO saturated (zfs would help here as well).
3) Changing the way packages are placed on the DVD so that we don't
need to seek the drive and can keep it at max trasfer rate. This
could involve placing the packages in one big cpio archive or
zfs backup^H^H^H^H^Hsend archive.
Besides significantly speeding up install from disk, 2) above will also
very much increase the speed of zone installation.
- Bart
--
Bart Smaalders Solaris Kernel Performance
barts at cyber.eng.sun.com http://blogs.sun.com/barts
