[9fans] Moving venti to another disk

[9fans] Moving venti to another disk

[Heiko Dudzus]

Unfortunately, the disk on which my venti is stored has more and more
read/write errors. (I will put venti on mirrored disks next time)

First I used venti/rdarena to get the arenas on cdrom. I initialized a
venti on another disk and tried:

# venti/wrarena -h <host> <arenafile on cdrom>

I tried to boot my fossil backed by the new venti. But fossil doesn't
find what it searches for. So, I think, I did not really understand,
how to use wrarena.

The second try was to directly do

# venti/wrarena -h <host> -o 335872 /dev/sdC0/arenas

(On my disk was the same offset as in ventiaux(8))

When I boot with this venti, the error is:
"mntgen: venti i/o error block <score>: no block with that score exists"

How to to this task right? I'm about to dd the partitions arenas and
isect from one disk to another. How would you do it?

Thanks in advance, Heiko

--
dudzus@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

Re: [9fans] Moving venti to another disk

[vdharani]

i have done similar thing (except fossil) before and i didnt face any
problem.

but i noticed a couple of things:

- if i invoke 'wrarena' twice, it took twice the space. so i think it
blindly copies rather than checking for existing data. this raises 2
questions: is venti still in good shape (since now two blocks for the same
score may exist)? if i backup up same or similar files in different venti
servers and later on i merge the venti server data using readarena and
wrarena, will it leave duplicate data blocks unnecessarily?

- you have to keep the venti score details (vac) seperately all the time.
else there is no way to get the signatures and venti may become useless
without it.

thanks
dharani

> Unfortunately, the disk on which my venti is stored has more and more
> read/write errors. (I will put venti on mirrored disks next time)
>
> First I used venti/rdarena to get the arenas on cdrom. I initialized a
> venti on another disk and tried:
>
> # venti/wrarena -h <host> <arenafile on cdrom>
>
> I tried to boot my fossil backed by the new venti. But fossil doesn't
> find what it searches for. So, I think, I did not really understand,
> how to use wrarena.
>
> The second try was to directly do
>
> # venti/wrarena -h <host> -o 335872 /dev/sdC0/arenas
>
> (On my disk was the same offset as in ventiaux(8))
>
> When I boot with this venti, the error is:
> "mntgen: venti i/o error block <score>: no block with that score exists"
>
> How to to this task right? I'm about to dd the partitions arenas and
> isect from one disk to another. How would you do it?
>
> Thanks in advance, Heiko
>
> --
> dudzus@sdf.lonestar.org
> SDF Public Access UNIX System - http://sdf.lonestar.org
>

Re: [9fans] Moving venti to another disk

[Heiko Dudzus]

vdharani@infernopark.com <vdharani@infernopark.com> wrote:
> i have done similar thing (except fossil) before and i didnt face any
> problem.
>
> but i noticed a couple of things:
>
> - you have to keep the venti score details (vac) seperately all the time.
> else there is no way to get the signatures and venti may become useless
> without it.

That was my problem with the first try. I used the score given by
! main: vac archive/2004/somedate

I still don't understand the difference between such a score and one
given on the fossil console after an archival snapshot. But now I know I
need the last type of score for flfmt.

My problem with venti/wrarena -o <offset> .. was that I thougt this would copy
all arenas following at <offset>.

After copying all arenas and using the right 'type' of score to format a
fossil, it works. But when fossil starts there appears an error message:

"err 2: arena creation time after last write time"

Initially, this was right, of course. But after the first archival
snapshot to the new venti this message shouldn't get displayed, should
it? But it's still there.

Regards, Heiko