# Error reading big file of a backup

**URL:** <https://kopia.discourse.group/t/error-reading-big-file-of-a-backup/220>\
**Category:** Support\
**Created:** [December 8, 2020, 10:44pm UTC](https://kopia.discourse.group/t/error-reading-big-file-of-a-backup/220 "2020-12-08T22:44:08Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![enboig](https://avatars.discourse-cdn.com/v4/letter/e/3be4f8/32.png) [@enboig](https://kopia.discourse.group/u/enboig)\
**Post date:** [December 8, 2020, 10:44pm UTC](https://kopia.discourse.group/t/error-reading-big-file-of-a-backup/220/1 "2020-12-08T22:44:08Z")

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I have problems restoring a backup of a VirtualBox disks (configured as VMDK, top file 2Gb).  
I use kUbuntu 20.04, latest version of [kopia.io](http://kopia.io) from repos, and S3 (wasabi) for repo storage.  
System reports a I/O error; how could I debug this? I would like to gather more information before posting an issue at github.

Thanks

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**Author:** ![enboig](https://avatars.discourse-cdn.com/v4/letter/e/3be4f8/32.png) [@enboig](https://kopia.discourse.group/u/enboig)\
**Post date:** [December 9, 2020, 10:03pm UTC](https://kopia.discourse.group/t/error-reading-big-file-of-a-backup/220/2 "2020-12-09T22:03:04Z")

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I restored the files with `kopia restore *snapshot*` and it worked; so the problem only appear on mounted snapshots. It may be a timeout?

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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:** [December 10, 2020, 3:25am UTC](https://kopia.discourse.group/t/error-reading-big-file-of-a-backup/220/3 "2020-12-10T03:25:25Z")

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Can you file an issue on GitHub with repro steps. This is probably a bug with vfs used when mounting.