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Checksum Checker is program that can run to verify the checksum of every item within DSpace. Checksum Checker was designed with the idea that most System Administrators will run it from the cron. Depending on the size of the repository choose the options wisely.

Command used:

[dspace]/bin/dspace checker

Java class:

Arguments short and (long) forms):


-L or --continuous

Loop continuously through the bitstreams

-a or --handle

Specify a handle to check

-b <bitstream-ids>

Space separated list of bitstream IDs

-c or --count

Check count

-d or --duration

Checking duration

-h or --help

Calls online help

-l or --looping

Loop once through bitstreams

-p <prune>

Prune old results (optionally using specified properties file for configuration

-v or --verbose

Report all processing

There are three aspects of the Checksum Checker's operation that can be configured:


Optionally, you may choose to receive automated emails listing the Checksum Checkers' results to the email address specified in the  mail.admin  configuration property. Schedule it to run after the Checksum Checker has completed its processing (otherwise the email may not contain all the results).  As of DSpace 4.1, an email is only generated if the selected report contains at least one bitstream needing attention.

Command used:

[dspace]/bin/dspace checker-emailer

Java class:


Arguments short and (long) forms):


-a or --All

Send all the results (everything specified below)

-d or --Deleted

Send E-mail report for all bitstreams set as deleted for today.

-m or --Missing

Send E-mail report for all bitstreams not found in assetstore for today.

-c or --Changed

Send E-mail report for all bitstreams where checksum has been changed for today.

-u or --Unchanged

Send the Unchecked bitstream report.

-n or --Not Processed

Send E-mail report for all bitstreams set to longer be processed for today.

-h or --help


You can also combine options (e.g. -m -c) for combined reports.

Cron. Follow the same steps above as you would running checker in cron. Change the time but match the regularity. Remember to schedule this after Checksum Checker has run. For an example cron setup, see Scheduled Tasks via Cron.

Database Query

A query like the following can be used to check the results of the checker:

Code Block
    substring(b.internal_id for 2) || '/' || substring(b.internal_id from 3 for 2) || '/' || substring(b.internal_id from 5 for 2) || '/' || b.internal_id AS bitstream_path, 
    hi.handle AS item_handle,
    hc.handle AS collection_handle
FROM checksum_history ch
JOIN bitstream b
ON ch.bitstream_id = b.bitstream_id
JOIN bitstreamformatregistry bfr
ON b.bitstream_format_id = bfr.bitstream_format_id
LEFT JOIN bundle2bitstream bb
ON b.bitstream_id = bb.bitstream_id
LEFT JOIN item2bundle ib
ON bb.bundle_id = ib.bundle_id
LEFT JOIN item i
ON ib.item_id = i.item_id
LEFT JOIN handle hi
ON i.item_id = hi.resource_id
AND hi.resource_type_id = 2
LEFT JOIN handle hc
ON i.owning_collection = hc.resource_id
AND hc.resource_type_id = 3
AND date_trunc('day', process_start_date) = CURRENT_DATE
ORDER BY ch.check_id DESC