[9fans] new arenas from the same disk

[9fans] new arenas from the same disk

[andrey mirtchovski]

i have a disk with two plan9 partitions (plan9 and plan9.1). the  
first one already hosts a 60 gig venti, fossil and all major  
necessities for a running plan9 system and is indeed working  
flawlessly. i would be very happy if anyone can point me towards any  
documentation on how to add the second plan9 partition to the running  
venti, increasing its size.

what i've done so far:

-create arenas.1 and isect.1 partitions on plan9.1;

-venti/fmtarenas arenas-two /dev/sdC0/arenas.1

-venti/fmtisect index-two /dev/sdC0/isect.1

what i'm thinking should be done next (according to my understanding  
of the man pages):

edit venti.conf and add isect-two and arenas-two thusly:

index main
isect /dev/sdC0/isect
isect /dev/sdC0/isect.1
arenas /dev/sdC0/arenas
arenas /dev/sdC0/arenas.1

- venti/fmtindex

reboot

from browsing the code it seems that fmtindex is for _new_ (therefore  
empty) arenas. is what i'm trying to do at all possible? what am i  
missing?

Re: [9fans] new arenas from the same disk

[Russ Cox]

You can run venti/fmtindex -a with a new config to add more
arenas, but if you want to add more index sections too,
you'll have to rebuild the entire index using venti/buildindex.

Russ

Re: [9fans] new arenas from the same disk

[andrey mirtchovski]

> You can run venti/fmtindex -a with a new config to add more
> arenas, but if you want to add more index sections too,
> you'll have to rebuild the entire index using venti/buildindex.
>
> Russ


ah, i have no extra partition to use as tmp for buildindex. i've done  
a 'fmtindex -a' for now.

the index is now 3.3% of the arenas space. it's at the lower end, but  
it should be fine, right?

something that's puzzling me -- can arena sizes be increased to fit a  
modern dvd? would venti benefit from this?

Re: [9fans] new arenas from the same disk

[Russ Cox]

> ah, i have no extra partition to use as tmp for buildindex. i've done
> a 'fmtindex -a' for now.
>
> the index is now 3.3% of the arenas space. it's at the lower end, but
> it should be fine, right?

that's fine.  venti will print errors when the index fills.

> something that's puzzling me -- can arena sizes be increased to fit a
> modern dvd? would venti benefit from this?

there's nothing wrong with writing multiple arenas to a dvd,
so if your arena size is 500M, you can just write nine of them.

venti mostly doesn't care about the size of the arena.
the total number of arenas determines some of the
memory footprint (two disk blocks per arena) but
even that is usually pretty small (one megabyte per
64 arenas assuming 8k blocks).

russ

Re: [9fans] new arenas from the same disk

[Russ Cox]

> ah, i have no extra partition to use as tmp for buildindex.

also, i have a buildindex in progress that does not need tmp.

russ