# Does kopia scan always all file content when creating a snapshot?

**URL:** <https://kopia.discourse.group/t/does-kopia-scan-always-all-file-content-when-creating-a-snapshot/644>\
**Category:** Support\
**Created:** [September 21, 2021, 8:10pm UTC](https://kopia.discourse.group/t/does-kopia-scan-always-all-file-content-when-creating-a-snapshot/644 "2021-09-21T20:10:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![guerby](https://yyz2.discourse-cdn.com/free1/user_avatar/kopia.discourse.group/guerby/32/222_2.png) [@guerby](https://kopia.discourse.group/u/guerby)\
**Post date:** [September 21, 2021, 8:10pm UTC](https://kopia.discourse.group/t/does-kopia-scan-always-all-file-content-when-creating-a-snapshot/644/1 "2021-09-21T20:10:46Z")

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Hi,

I couldn’t find reference to file metadata like ctime/mtime/size to avoid re-reading all data an unchanged file in the kopia documentation, some backup software have this feature:

[https://borgbackup.readthedocs.io/en/stable/usage/create.html#description](https://borgbackup.readthedocs.io/en/stable/usage/create.html#description)

Does kopia implement this and if no is it planned?

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**Author:** ![jkowalski](https://yyz2.discourse-cdn.com/free1/user_avatar/kopia.discourse.group/jkowalski/32/3_2.png) [@jkowalski](https://kopia.discourse.group/u/jkowalski)\
**Post date:** [September 21, 2021, 8:31pm UTC](https://kopia.discourse.group/t/does-kopia-scan-always-all-file-content-when-creating-a-snapshot/644/2 "2021-09-21T20:31:36Z")

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Yes. Kopia does that by default. To force rereading file even if modification time matches you can pass —force-hash flag set to a percentage (0…100). This will apply to the specified percentage of files.