[Building Sakai] [Management] avoid duplicate files in courses

[Matthew Jones]

There's nothing built into Sakai that does this automatically. There have
been some feature requests that might have gotten part of the way to making
this happen, like SAK-12340 [1] (Create a resource-type that functions as a
"symbolic link" or "alias" for another resource) but it was marked as a
Won't Fix a while ago. To get it to work you'd have to change the content
hosting back-end to keep track of unique files and make symbolic links on
the file system when identical files are created. Not sure which algorithm
you'd go with for that. This process is somewhat described in [2] but not
implemented at all in Sakai.

Typically if you need this, what you can do this is either get some hardware
or software that does this for you. (Which there is a lot of) The most
popular commercial hardware are probably the NetApp Filers which have the
DeDup technology built into their NAS. [3] But there are also a bunch of
other vendors listed on [2]. The open source filesystem link listed here,
LessFS [4] looks like it's a pretty active product that (passed 1.0 release)
could give you this type of functionality is of high importance to you. With
Sakai you can store all of your binary content on the file system [5], and
use fuse running on linux with a LessFS formatted partition.

Probably more work than you were expecting but it looks like the best you'll
get easily.

I'm not sure if deduplication is in the plan for Sakai 3 or not.

[1] http://jira.sakaiproject.org/browse/SAK-12340
[2] http://www.linux-mag.com/cache/7535/1.html
[3] http://en.wikipedia.org/wiki/NetApp
[4] http://www.lessfs.com/wordpress/
[5]
http://confluence.sakaiproject.org/display/DOC/Sakai+Admin+Guide+-+Binary+Content+and+Filesystem+Settings

-Matthew


On Tue, Mar 16, 2010 at 7:57 PM, Eduardo Ponce de León Carreto <
eponcedeleon at sicom.com.mx> wrote:

>  does anybody know how can I avoid duplicate files... I have a file that is
> used in 100+ courses...If i upload that file to every course that would mean
> a lot of space for those 100files. Is there a way to avoid this. I am asking
> this because we are planning on moving from blackboard to sakaii as content
> system in blackboard is way too expensive. Is this possible in sakai?
>
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