[Server-devel] Server Spec (blueprints) Comments

[Martin Langhoff]

On Wed, Aug 6, 2008 at 4:20 AM, Greg Smith <gregsmitholpc at gmail.com> wrote:
> Also, is that the right place for them? Are they in 0.3 and is it
> "released" with both those features implemented? When a new release
> comes out, maybe we should note that its released in the road map and
> link to its release notes?

Yes, but I don't think we have achieved all the goals in it, so I
won't call it "done" -

> Great job describing scenarios and motivation on both. That's key
> element in understanding the motivation and use of the features!

Thanks - normal practice from my moodling days :-)

> Some comments and questions:
> http://wiki.laptop.org/go/XS_Blueprints:Datastore_Simple_Backup_and_Restore
>
> 1 - What files are backed up from the XO?

Everything that is tracked by the datastore. The hint is in the name :-)

> 2 - Is there any GUI on the XO for this feature? Is it always on or
> always off or how do you know when it is moving files from the XO view?

- always on
- a ui improvement could be to add a hint that ds-backup is working

> 3 - How many XOs can backup at the same time? If they start to swamp the
> BW during class, is there any way to know that and possibly prevent it
> if needed? Looks like the traffic control script does some of that but
> could use more details on the algorithm.

Impossible to know how many. There are several mechanisms we use to
control this. It will be *fantastic* if someone can document this to
the last detail, and update it every time we change the code. In the
meantime, read the source.

The traffic control algorithm is here - line 17 and 28-37 are interesting:
http://dev.laptop.org/git?p=users/martin/ds-backup.git;a=blob;f=server/backup-available.py;h=b7a2dab0115601737c641cb5e2bb2038a9963461;hb=413237674d734101dc8c22639a96eba35ddac2a4

> 4 - Can you set the "quota" per XO? What is the default? How about max
> age? Do you turn this feature on with the XS and what is the interface
> to it on XS?

No. Dynamic based on a per-service quota. Again, need for
documentation helpers. Good docs take at least as much time to write
as the code itself.

> On http://wiki.laptop.org/go/XS_Blueprints:OTP_root_passwords
>
> 1 - My only question is if we have a lead customer for this. I would
> like to hear Bryan's comments on it too.

The blueprint talks about deploying large numbers of XSs, some of them
w/o internet. Who could that be? :-)

cheers,



m
-- 
 martin.langhoff at gmail.com
 martin at laptop.org -- School Server Architect
 - ask interesting questions
 - don't get distracted with shiny stuff - working code first
 - http://wiki.laptop.org/go/User:Martinlanghoff