[9fans] Venti r/o directory

[9fans] Venti r/o directory

[maht]

Hi,

I'm doing Windows -> Venti using Limbo

In general all is well.

But when I unvac the resulting score with 9p9 on Debian it segfaults
because 'My Documents' is dr-xr-x-- so unvac creates a read only
directory and then tries to write into it.

I've got round it for now by chmoding 770 'My Documents' 'My
Documents/My Pictures'  'My Documents/My Music' but in the general case
I plan to not be in control of that, plus if we copy anything from
DVD/CD-ROM  it ends up r/o on Windows.

The only general purpose solution I can think of is two passes for unvac
but that doesn't sound very nice.

btw. it is a great way to backup. < 1% of CPU while running, which is
doubly fortunate because vacput doesn't have an option to compare
against previous backups

Re: [9fans] Venti r/o directory

[erik quanstrom]

> But when I unvac the resulting score with 9p9 [sic] on Debian it segfaults
> because 'My Documents' is dr-xr-x-- so unvac creates a read only
> directory and then tries to write into it.
>
[...]
>
> The only general purpose solution I can think of is two passes for unvac
> but that doesn't sound very nice.

wouldn't it suffice to set temporary permissions of 777 and fixup
when leavinging that directory?

> btw. it is a great way to backup. < 1% of CPU while running, which is
> doubly fortunate because vacput doesn't have an option to compare
> against previous backups

so you're completely disk bound?  if disk activity on the windows
box is also low, your venti machine must be suffering.

- erik

Re: [9fans] Venti r/o directory

[maht]

>
> wouldn't it suffice to set temporary permissions of 777 and fixup
> when leavinging that directory?
>
depth first, so it could be a while in between. Not really a massive
problem but still an issue

>
>> btw. it is a great way to backup.<  1% of CPU while running, which is
>> doubly fortunate because vacput doesn't have an option to compare
>> against previous backups
>>
> so you're completely disk bound?  if disk activity on the windows
> box is also low, your venti machine must be suffering.
>
>
>
seems so. It is an old windows box but the activity light isn't
constantly on. The only way I can tell it's doing anything top (venti is
around 20% CPU (2Ghz) on a RAID1 or by watching http://127.0.0.1/storage

Re: [9fans] Venti r/o directory

[maht]

>> so you're completely disk bound?  if disk activity on the windows
>> box is also low, your venti machine must be suffering.

It took just over 8 hours to copy 2.2Gb of data from an idle system to a
mostly idle system. The network is 1gbit.

So it's not maxing out the disk, not maxing out the cpu and not maxing
out the lan but taking an inordinate amount of time.

Maybe it's XP's scheduler, I suspect Scheduled Tasks (their cron) run at
quite low priority, though on an idle machine .....

I just looked at the Limbo and there's scope for adding multi-threading,
that should stir things up a bit.