Media Files
Fixity Tutorial v.0.4
AVP Videos
Creator AVP
created 2014
digital preservation
A short how-to and introduction to AVP's Fixity tool (v 0.4), a free, open source application that can support organizations or individuals by providing automated review, documentation and reporting on the integrity and attendance of stored files. In this video, we explore the Fixity version 0.4 release for the Apple OS, and highlight additional features available on the Windows version. Find out more at

Primary English
created 2014
Creator AVP
Rights Statement:
CC BY 4.0

Preferred Citation:
Fixity Tutorial, AVP, 2014

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Thank you for your interest in AVPreserve's Fixity tool, it is a free,
open source application that can help organizations and individuals ensure
the data integrity of their collections of digital files through automated
review documentation, and reporting. In this video, we will explore The
Fixity version 0.4 release for the Apple operating system and highlight
additional features available on the Windows version. The Fixity tool scans
one or more folders or directories creating a manifest of files,
including their file paths, checksums and index values against which a regular
comparative analysis can be run. The comparative analysis is run automatically
according to a user defined schedule. The utility monitors both file integrity
and file attendance, reporting on new, moved, removed, renamed and changed
files. Fixity emails identified addresses with reports on the status of
all files within a project. It's an easy to use tool that automates
repetitive, but essential functions related to fixate checking, monitoring
and reporting. To begin a new project, click file>new project. I named my
new project fixitydemo and click okay, or hit enter.
In Fixity you can choose to run monthly, weekly, or daily scans.
I choose weekly on Saturdays at 9 AM. Fixity uses military time,
so 9 AM is 0 900 and 9 PM is 2100.
Below the schedule information are preference check box options. In the
Windows version of Fixity, these are options for whether or not the application
should run when a laptop is running on battery power and/or to run
upon restart if the computer is off at the time of the scheduled
scan. On the macOS, the application will run on battery power by default
and missed scans are not run upon restart. If missed, the next scan
will be performed at the next scheduled time.
The email check box preference allows you to decide when you want to
receive email reports. If unchecked, emails are sent to the identified recipient
email addresses every time a scan is performed, regardless of the results.
Since this is a project level preference, and I want to see all
results of my scan, I leave the check box for email report preference
Select the directory to be scanned. Fixity allows up to seven different
directors to be included in each project. You may also enter up to
seven recipient email addresses for reports to be sent, please note
although it visually appears as if there is an email address assigned per
directory, this is not the case. Fixity scans all selected directories and
emails the report to all recipient email addresses.
In order for Fixity to be able to send these email notifications,
you will need to configure the sender email.
Under preferences, click on email settings. Fixity provides the server,
port, and security information for Gmail authentication by default. These
are the same settings that you have in your email application,
such as Outlook, or macmail, so you may find the information by looking
into your account settings within your mail application.
Click check credentials this will sign to test email to your address.
If you received this email you have successfully configured the sender email
address. It is critical that the sender email is configured, otherwise Fixity
will not be able to send notifications or reports. Click Save and Close,
then save the Project Settings. Under preferences, click Filter Files
this window allows you to create filters to prevent Fixity from scanning
certain files. For example, files such as DS store or thumbs.db are automatically
created by certain operating systems, but you may not be concerned about
preserving them and may wish to exclude them from your scan. This can
be done by adding them to the filter. Select the desired project from
the drop down menu. I choose to filter out .thm which are thumbnail
files. Tthis text box allows separated case sensitive filters.
Save filters settings by clicking Save and Close and save the project again.
Fixity checksum algorithm setting allows for projects to use either SHA
256 or MD5 to calculate checksums. Click on Preferences, and then select
Checksum algorithm. In this scenario, I choose MD5. Save checksum settings,
and save the project. It is best to select the checksum you will
use before running a project, however, if you change the checksum algorithm
after a project has already generated fixity values for its files,
the project will safely generate new values for each file using the new
algorithm in the next run. Under file, click Run Now to run a
fixity scan immediately instead of using scheduling. The scan runs in the
background. Upon completion a report is generated and depending on notification
settings recipients may or may not receive an email. Fixity saves all reports
locally to your computer. In the Fixity directory within the Reports folder
you will find a tab separated value or TSV file.
In addition to automatically saving reports to your machine, Fixity sends
an email notification of the scans results, with the same TSV file attached
in a summary report in the body of the email.
To understand what file attendance alerts are in Fixity, I altered some
of the previously scanned files to demonstrate the results of the scan.
I changed the content of a text file by opening it,
adding a new text and saving it. I edit the file name of
a different file without opening it, I create a sub directory in one
of the scan directories and move a file to it, I delete a
different file and I add another file from the desktop into one of
the directors being scanned.
For this demonstration I can either update Fixity scheduled run to happen
momentarily, so I can review the resulting report, or just click File and
Run Now. Note every time I choose Run Now Fixity saves the project
One way to view the scans results is to import data from the
TSV report into Excel, the report states that some of my files weren't altered
and confirmed to be in the same location and generate the same checksum
as they did in the last scan. Notice Fixity detected and identified the
changes I made to the files in my target directories.
For moved or renamed files, the report captures what the file was changed
to, seen here in column D.
These TSV reports provide a record of actions taken or not taken on
files and targeted directories. The processes during products of any actions
are captured and made available in the extendable TSV format and the tool
can be slotted into most workflows easily due to its simplicity and effective
management of Fixity and file attendance.
Each time a scan is run a snapshot of the data,
as it exists at that moment, is saved to the history folder in
the Fixity directory, this provides an audit trail over time and the ability
to refer to a previous snapshot or state of the target data.
A fixity report represents the differences and similarities between two
history snapshots. The snapshot TSV file is named with project name,
the date and the time of capture in military time.
History snapshot headers include: the directory selected for scanning for
a given project, recipient emails for a given project,
schedule information, including codes identifying project schedule settings,
the date and time that the project was run and the file was
created and excluded files from the scan as entered into the filtering feature.
The bulk of the snapshot details the hash value, file path and index
value for each file scanned. History snapshots provide a granular record
of the state of your files at a specified time.
Fixity and its accompanying documentation from AVPreserve were designed
to address the importance of checksums in file attendants and satisfy the
need for routine verification and management. Ideally, organizations could
use the automation that Fixity provides to save a tremendous amount of staff
time and work towards overcoming the challenges that keep many organizations
from properly managing digital collections. We would love to hear how you
are using the tool, as well as any feedback you may have.
Please contact us at fixitytool at AVpreserve dot com. Thanks!