The management issue of PST files is still very much present, even if many firms have taken steps to centralise PST data, as shown by the abundance of inquiries on industry forums asking why OneDrive cannot back up PST files. Let us quickly review how we ended up in this situation.
Causes of the PST Files issue
Due to the high cost of the disks required by the early versions of Microsoft Exchange, IT departments had to impose severe size restrictions on each mailbox. Users frequently drop emails into offline files with the extension.pst (Personal Storage Table) when they reach their storage limit, allowing content to be saved locally without impacting the server.
PST files, however, can provide serious risks. They functioned more like a zip file for your email and were not intended for secure storage. Sadly, various programs to remove or “crack” passwords are readily available, even though the passwords do not offer encryption; they merely serve as a prompt for people to open the file. As a result, moving PSTs (Personal Storage) around is simple for users and malicious actors, leading to data exposure.
Numerous enterprises have deployed sophisticated Email Archive platforms to reduce the strain on Exchange servers over the years. Users thought these offered bottomless email but in a more affordable setting. The re-centralisation of the data in the archive systems addressed many security issues. These were used by organisations for eDiscovery and other purposes as well.
However, most enterprises today find PSTs and Email Archive Systems unnecessary because cloud-based email solutions (like Exchange Online) offer almost unlimited storage and robust eDiscovery features. As a result, the previous workarounds are no longer effective, even if dragging emails off the server is still far too familiar because it is so established in user behaviour.
Email PST migration to Exchange Online is essential to centralise the data because PSTs cannot linger in the background due to the hazards. The critical question for this post is why OneDrive cannot back up PST files because migrating the data might be challenging. Many businesses incorrectly think OneDrive is a natural home in the cloud.
Why using OneDrive for PST files is not a good backup plan?
Although PSTs are considered outdated data, this is not the case for many users. For their professional functions, these files frequently contain crucial and up-to-date information. Many businesses that switch to OneDrive for user storage wish to abandon desktop backup programs in favour of the OneDrive sync client. Although this makes sense in theory, it is not feasible.
Small database files are called PSTs. Although administrators can transport email data, Microsoft Outlook users often use them. These files are locked once opened and can be accessed by one user at a time.
Local caches of the files you store in OneDrive are kept on your computer. The cache settings, which regulate what is cached, determine which files are locally stored. The OneDrive sync client will start and download the chosen file if it is not already downloaded so that you may open it. The sync client will upload new versions of the files behind the scenes. Using specific policy settings, you can require devices to upload files from numerous popular places to OneDrive.
Many businesses use this to remove backup software from endpoint devices. All the data is stored in OneDrive and can be easily downloaded again if the device is lost or stolen. This satisfies the demands and expectations of numerous businesses.
PST files, however, negate this idea.
First, flow and access violations are a problem. Microsoft Outlook is typically used all day long. This will freeze the file for users dependent on PST files and stop the OneDrive sync client from uploading it to the server. Although you might initially succeed in uploading the file, changes might never upload. The second problem with PSTs being database files is now brought up.
The complete database file needs to be transferred to OneDrive whenever a user makes even the most minor update to an item in the PST file. The entire 20GB PST file will need to synchronise back to OneDrive to “backed up” if you have a 20GB PST file and add a 75K email.
Due to these two problems, users must shut down Outlook and allow the OneDrive sync client to perform its job before PST files are frequently backed up to OneDrive. This may take a long time if the user has enormous files and a slow connection. These files will never return to OneDrive in reality.
As a result, a lot of customers will see the following start caution in Microsoft’s instructions for backing up files to OneDrive:
Outlook database files (.pst) cannot be protected as the following file type.”
Microsoft also changed the version retention policy for PST files stored on SharePoint/OneDrive in August 2021. This shows how much room these files have been consuming and the necessity to reduce their size. Future versions are only stored for users for 30 days. This offers consumers 30 days to identify problems and save earlier versions. If a user does not discover this within 30 days, they will have to try to repair the file, which has conflicting outcomes.
Things to do
Data protection is essential for organisations on many levels. This keeps users engaged and guarantees that businesses follow data retention rules and standards.
You have four choices:
Organisations with local PST files should be aware of this danger and take steps to address it. These backup concerns will continue to be problematic for users who frequently use PST files. If you do not look for other ways to delete PSTs completely, you need to centralise this data into Exchange or another system.
One thing is sure: OneDrive is not your backup for storing PST files locally.
There are various PST migration options available to you:
- PST Import Service by Microsoft
You might be able to use the Microsoft PST Import Service for businesses with a modest number of PSTs or when files are already centralised. It costs money but knowing where every file is and to whom it belongs can be the best way to migrate to Exchange Online. Files are either physically sent on a hard disk or transferred to Azure cloud storage. You include a mapping in this upload scenario and start importing data into user mailboxes.
- External resources
You need advanced tooling if your PST files are dispersed and you are unsure to whom the files belong. These third-party PST migration solutions will aid in the data transfer, de-duplicate emails, filter out unnecessary emails, apply retention tags, delete the source files, scan for ownership, and remove PST file passwords.
Conclusion
It would help if you considered removing PST files from these computers to eliminate desktop backups using OneDrive for Business.
Using PST file migration to network shares is also not advised as a remediation strategy. Bear in mind that, although being a frequent practice, storing PST files on network shares is not supported by Microsoft and is very susceptible to corruption.