meino.cra...@gmx.de writes:
> I think there is some misunderstanding:
>
> Before migration to 64bit:
>
> /dev/sda3 is mounted on / and contains the 32bit Gentoo
>
> /dev/sda10 is mounted on /home/mcc/migration and will contain the
> stuff of the 64bit Gentoo
>
> After migration I will *not* mount /dev/sda10 on / but will clear all
> stuff from /dev/sda3 and move the contents from /dev/sda10 to
> /dev/sda3.
>
> Is still valid what you said under this premissions, Wonko?
That's how I understood it, although I assumed the temproary 64bit install
would be on a 2nd drive, thus you would copy it back once it seems to
work. No, I see no problem with this.
About performance: I'm not sure it will be even noticeable. Yes, most
drives (but not all) are organized so the first partitions go to the
outside, which is faster. With LVM, I used to create two volume groups on
my drive, a group for swap and the system, and another one for data. But
then I thought it's not worth the effort, and I lose some of the LVM
benefits. Well, with everything encrypted I don't get full performance
anyway, so my case might be a little different.
But the performance increase is only true when reading lots of data. I'm
not sure how big the role of this is in real life. Access time is not
influenced, it will on average take half a turn of the drive till the
heads can access the data, and to me it looks like typical stuff a linux
system does is reading many not so large files, cluttered around in the
file system. But that's my guess only. And I understand that you like to
optimize stuff - I like to do this too. But sometimes I think that the
potential benefit might not be so large, compared to the time I spend
moving data around to the ideal place, or the time I would need to spend
thinking about how to tune things. Or the time you need to fix a problem
that you know was working in the old system, but this is gone now and you
cannot have a quick look at it, or just boot into it. You lose the
opportunity to start your old system in order to compare the times of your
big renderings. And maybe at one point you need to create some true 32bit
applications? Happened to me. So I just chroot into my old system and
build there.
Oh, and you mentioned databases. Yes, mysql stores itsa data in machine-
depenent form. You will need to dump the data and re-import it in the new
system. You will be happy to still have the 32bit system in such a case :)
Wonko
