- Dspace stores data like bitstreams, metadata, and licenses in its assetstore directory, while information about communities, collections, users, and permissions is stored in PostgreSQL databases. - The export and import functions in Dspace deal only with bitstreams, metadata, licenses, and handles, but do not transfer information about communities, collections, users, and permissions. - To export a collection, the export command is run with options to specify the type as collection, collection ID, destination directory, and sequence number. A shell script can then automate exporting multiple collections.

1. Export/Import in Dspace & Backup
ARD Prasad

2. Where Dspace stores data

/dspace/assetstore directory will have all the
− Bitstreams and licenses

PostgreSQL databases contains information on
− Metadata
− Information about Communities
− Information about Collections
− Information about e-groups & authorizations
− Information about E-persons & authorizations
− Host of other information

3. Export/Import in Dspace

Export and import deal only with bitstreams,
metadata, license and handles.

But NOT information about communities,
collection, members, reviewers etc., access
permissions/restrictions

You can export or Import
− An item or
− All items in a collection

4. Export command syntax
/dspace/bin/dsrun org.dspace.app.itemexport.ItemExport
--type=COLLECTION --id=collID
--dest=dest_dir --number=seq_num
Where
--type can have either the value COLLECTION or ITEM
--id is the handle/collection_or_Item_Id ex: 1849/2
(or 123456789/2 in case you do not have handle)
--dest is destination directory
(directory be created prior before running the script)
--number is sequence number, it can be just 1

5. Shell Script for exporting
#!/bin/sh
if test $# != 1
then
echo "Usage: $0 <export-directoryname>"
exit
fi
declare collection_id[5]=(2 3 4 5 6 7)
for((i=0; i<=5; i++))
do
mkdir $1/${collection_id[$i]}
/dspace/bin/dsrun
org.dspace.app.itemexport.ItemExport
--type=COLLECTION
--id=1849/${collection_id[$i]}
--dest=$1/${collection_id[$i]}
--number=1
done

6. In the shell script...

Look for the line

declare collection_id[5]=(2 3 4 5 6 7)

Change 2 3 4 etc with your collection ids

Clue: collection ids are the one that appear in the
browser URL after handle prefix, ie. If you have not
registered with CNRI, the number that appears after
123456789/

Also create the directory where the data should be
exported to

7. Shell Script for Import
#!/bin/sh
declare collection_id[5]=(2 3 4 5 6 7)
for((i=0; i<=5; i++))
do
/dspace/bin/dsrun
org.dspace.app.itemimport.ItemImport
-a -e dspace@localhost.localdomain
-c 123456789/${collection_id[$i]}
-s $1/${collection_id[$i]}
-m mapfile
done

8. 
Here also change the collection ids in the import
progam

-e option, should have the dspace admin id (i.e. e-
mail address)

9. What is exported

The following files will be created for every item
− dublin_core.xml ( metadata)
− Handle ( one line having the handle number)
− license.txt
− Actual file ( bitstream: could be pdf or doc or an
image file)
− Contents (with two lines – license file name, and
actual bitstream name)

10. However

Import and Export are meant for data exchange

It can however, be used for partial back up

It takes care of only items

It does not back up
− Your communities, collection, e-groups, e-persons

11. How to backup postgresql

pg_dump as dspace user

Example:

$ pg_dump dspace > backupfile

Note: where dspace is name of the database

backup file will have all the table definitions and
contents.

pg_dump has lots of options

12. How to restore database

psql -d dspace –f dumpedfile

Note: pgsql has lots of options, to know more
about options, you can use

13. Alternative (using tar)

To dump a database called mydb that contains
large objects to a tar file:

$ pg_dump -Ft -b mydb > db.tar

To reload this database (with large objects)
to an existing database called newdb:

$ pg_restore -d newdb db.tar

14. Upgrading

This procedure should be first step when you are
upgrading DSpace to newer version

Even if upgradation fails, you have back to fall
back

15. Upgrading Tip

Have different database and as a different user, so
that you do not have to touch the existing DSpace
insallation

16. Extra care

It is a good idea to take a tape (hard disk) back up
of
− Entire /dspace directory
− pg_dump out put file
− And the export directory

17. Final Lesson

Learning dspace is too easy.
− can be learnt in a week
− Can be mastered in a month

Creating content is continuous, long-term,
perhaps no end

Be more careful with the Content

18. Thank You