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GlossaryUnstructured Data BasicsROT data
ROT data
ROT stands for redundant, obsolete, and trivial. Redundant is duplicated, obsolete has passed its useful life, and trivial never had value. It is the part of an estate that can be removed with the least argument, which makes it the first capacity most teams reclaim.
Key takeaways
- Duplicates, outdated versions, and files nobody uses make up most ROT data.
- Teams keep ROT data because removing it feels riskier than keeping it.
- It is found from metadata such as duplicates, last access date, and owner, then reviewed before cleanup.
What are examples of ROT data?
Every organization has some of each kind:
- Redundant: the same video or design file copied into several project folders, backups of backups, and email attachments saved to shared drives again and again.
- Obsolete: old versions of documents, files from projects that ended years ago, data past its retention period, and folders left by people who have left.
- Trivial: temporary files, caches, logs, thumbnails, and failed or partial transfers that were never cleaned up.
How much ROT data do enterprises store?
There is no single current figure, but every measurement points to a large share. Veritas’s Global Databerg Report found that 33% of stored data was ROT, although that study dates from 2016. In Diskover deployments, 30% to 50% of storage is typically reclaimed by tiering and removing ROT data, and one global advertising group found that 39% of its 1.6 PB of Amazon S3 storage was ROT. The only reliable figure for a given organization comes from measuring its own storage.
What is data hoarding, and why does it happen?
Data hoarding is retaining data past its useful life because removing it feels riskier than keeping it. It happens when three things are unrecorded:
- What the file is for
- Who owns it
- Whether anyone still needs it
The fix is description rather than persuasion. Once those three have answers, the decision stops being a gamble.
How do you find ROT data?
Each of the three parts has its own signals, and all of them can be read from metadata:
- Redundant: copies of the same file, found by duplicate detection across storage systems.
- Obsolete: files past their retention period, from closed projects, or owned by people who have left.
- Trivial: temporary files, caches, logs, and failed transfers, usually found by file type and path.
Is it safe to delete ROT data?
Most of it, once it has been reviewed. Trivial data such as caches and temporary files is usually safe to remove after a short check. Redundant data is safe to remove once one copy is kept as the original. Obsolete data needs the most care: check retention periods and legal holds first, and confirm with the owner or the owner’s manager. A common approach is to move ROT to low-cost storage first, wait a set period, and delete it only if nobody asks for it back.
How does Diskover help?
Diskover finds duplicate, old, and abandoned files across your storage systems from their metadata, so your team can review the list and clean up with confidence.
Sources
- Veritas, Global Databerg Report (Vanson Bourne), March 2016: 33% of stored data is redundant, obsolete, or trivial.
- Diskover customer results, self-reported: 30% to 50% of storage reclaimed through tiering and removing ROT data; a global advertising group found 39% of 1.6 PB of Amazon S3 storage was ROT.
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Last updated: November 13, 2026.
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