[Server-devel] Journal backup on school server

[George Hunt]

Hi Tony,

I'm playing with ds-backup now, because one of the dependencies for
ds-backup is mod_python which was dropped from fedora 18, in favor of
mod_wsgi. It seems like a great time to rethink the issue.

I cannot find the working code you mention in this email in my google
stack.  Can you send it to me again?

I'm also talking with Tim Moody, about using puppet client as a way of
pushing and modifying the configuration of XO's in the classroom.  Do you
have any experience, or ideas, about such a proposal? I'm not sure whether
ds-backup might be used to introduce puppet client back into XOs.

George

On Sun, Dec 9, 2012 at 12:25 PM, Tony Anderson <tony_anderson at usa.net>wrote:

> Hi,
>
> I will send you the scripts as soon as I have a chance to try them on
> 12.0.1 and XS-0.7. Last year they were running on xs-0.6 and build 852 at
> Saint Jacob. There shouldn't be too much difference, although so far on
> most of the code I have been wrong by about 3 days!
>
> The identity problem really isn't that hard. A lot of the mailing list
> discussion seems related to running Sugar on something besides an XO.
>
> The user is identified on the server by the serial-number. For the backup,
> this is not a problem. The problem comes from <OLPC where an XO is shared.
> Then there needs to be something like a login to identify the actual user.
> There also needs to be separate Journals on the XO and separate backups on
> the school server.
>
> I should be able to give you working code within a week (I leave Kigali on
> 12/23 so it must be before then).
>
> Yours,
>
> Tony
>
>
> On 12/09/2012 04:11 PM, George Hunt wrote:
>
>> Wow Tony,
>>
>> Your solution definitely needs to be part of the mix as we go forward.
>> Can you send me copies of the scripts, or the changes you made to
>> accomplish these objectives?  If we are going to look at the
>> serialnumber-user-identity issue, we might be making changes to the same
>> packages.
>>
>> Have you worked through the changes needed to add user identity to
>> journal backups? As Paul Fox was suggesting, I think there will be lots
>> of ripple effects, if and when we start adding additional users, in
>> addition to the user "olpc".  Or maybe, someone will come up with a
>> simplifying assumption, or approach.
>>
>> George
>>
>>
>>
>> On Sun, Dec 9, 2012 at 4:49 AM, Tony Anderson <tony_anderson at usa.net
>> <mailto:tony_anderson at usa.net>**> wrote:
>>
>>     Hi, Sameer
>>
>>     I got an email from Nick Doiron re his visit to the Marshall
>>     Islands. He mentioned that you gave him a script to create a csv
>>     from the Journal backup.
>>
>>     As I have mentioned several times on the list, I believe Martin's
>>     backup scheme while elegantly implemented is not adequate. His model
>>     is the traditional backup/restore.
>>
>>     The problem, as always, is storage space. When an XO-1 is out of
>>     space, the user gets a message 'Journal is full'. The only practical
>>     solution often is to reflash the XO losing all of the Journal
>>     objects. If a user deletes an object from the Journal on the XO, the
>>     rsynch also removes it from the backup.
>>
>>     I modified the scripts ds-backup.sh and ds-backup.py on the XO to
>>     use a different paradigm. The registration process creates two
>>     scripts in the /library/users/serial-number folder on the school
>>     server: journal and log. The backup script uploads the object to
>>     journal if there is an associated data file; otherwise, it is
>>     uploaded to the log folder and deleted from the local store. The
>>     remaining objects are marked as favorites in the Journal Activity to
>>     show that the data file is available on the XO. If the user clears
>>     the star, the data file is deleted from the datastore but remains on
>>     the school server. If the user fills a clear star, the backup script
>>     downloads the data file from the school server.
>>
>>     At Saint Jacob, all of the laptops are 4gb XO-1.5 so I have not had
>>     to implement storage management. The plan would be to set limits on
>>     the size of the datastore and the /home/olpc/Activities folders. If
>>     a datastore outgrows the limit, data files can be deleted LRU.
>>     Similarly, activities can be deleted LRU. This way the user will not
>>     have to be involved. The user can always request a needed file to be
>>     restored to the local datastore and can request an activity be
>>     downloaded and installed from the school server repository. I expect
>>     this will be needed in Lesotho for XO-1.
>>
>>     This method also supports restoring the users Journal after a reflash.
>>     It also enables a replacement laptop by renaming the serial-number
>>     folder on the school server (and updating the registration
>> information).
>>
>>     I am not sure if you are trying to implement this functionality, but
>>     it is important at a deployment.
>>
>>     Yours,
>>
>>     Tony
>>
>>
>>
>
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