# Backup size 170mb, userdata/core most of it

**URL:** <https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055>\
**Category:** Beginners\
**Created:** [March 8, 2022, 11:35pm UTC](https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055 "2022-03-08T23:35:15Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Chura](https://community.openhab.org/user_avatar/community.openhab.org/chura/32/37400_2.png) [@Chura](https://community.openhab.org/u/Chura)\
**Post date:** [March 8, 2022, 11:35pm UTC](https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055/1 "2022-03-08T23:35:15Z")

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Hi

What is userdata/core ?  
Mybackup’s are 178mb big, and most of the size is coming from that file

 ![image](https://community-openhab-org.s3.dualstack.eu-central-1.amazonaws.com/original/3X/a/d/ad412a97ddd616a4c21600ec56045d563707d789.png)

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**Author:** ![Wolfgang\_S](https://community.openhab.org/user_avatar/community.openhab.org/wolfgang_s/32/52719_2.png) [@Wolfgang\_S](https://community.openhab.org/u/Wolfgang_S)\
**Post date:** [March 9, 2022, 6:46am UTC](https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055/2 "2022-03-09T06:46:48Z")

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In the same directory next to this file you find directories like cache, etc, jsdondb ? Is that correct ?  
Then I assume that the core file is a [core dump](https://en.wikipedia.org/wiki/Core_dump).

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<div class="post-metadata">

**Author:** ![Chura](https://community.openhab.org/user_avatar/community.openhab.org/chura/32/37400_2.png) [@Chura](https://community.openhab.org/u/Chura)\
**Post date:** [March 9, 2022, 1:12pm UTC](https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055/3 "2022-03-09T13:12:06Z")

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Not that I can see

 ![image](https://community-openhab-org.s3.dualstack.eu-central-1.amazonaws.com/original/3X/d/f/df632de55aa1730ba05cd9095ef3128892d6e81e.png)

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<div class="post-metadata">

**Author:** ![Chura](https://community.openhab.org/user_avatar/community.openhab.org/chura/32/37400_2.png) [@Chura](https://community.openhab.org/u/Chura)\
**Post date:** [March 9, 2022, 1:24pm UTC](https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055/4 "2022-03-09T13:24:31Z")

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Inside core file

 ![image](https://community-openhab-org.s3.dualstack.eu-central-1.amazonaws.com/original/3X/c/7/c7eb8d15ffe7cd138215f9baff910b1ad10fc3da.png)

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<div class="post-metadata">

**Author:** ![Chura](https://community.openhab.org/user_avatar/community.openhab.org/chura/32/37400_2.png) [@Chura](https://community.openhab.org/u/Chura)\
**Post date:** [March 9, 2022, 1:28pm UTC](https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055/5 "2022-03-09T13:28:50Z")

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Well, you was right

@daled:/openhab/userdata# cat hs\_err\_pid697.log | grep core

# Core dump will be written. Default location: /openhab/userdata/core

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<div class="post-metadata">

**Author:** ![bolemo](https://community.openhab.org/user_avatar/community.openhab.org/bolemo/32/49266_2.png) [@bolemo](https://community.openhab.org/u/bolemo)\
**Post date:** [June 25, 2025, 11:09am UTC](https://community.openhab.org/t/backup-size-170mb-userdata-core-most-of-it/134055/6 "2025-06-25T11:09:05Z")

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This is still currently an issue (OH 4.3.X) for backups as it creates a lot of iowait and huge backup files…  
Why not simply exclude core dumps from backups?

Right now, the backup is made like this: `tar --exclude=/openhab/userdata/backup -c -f /openhab/userdata/backup/userdata-YYYY-MM-DDThh-mm-ss.tar /openhab/userdata`

Why not do it like this? `tar --exclude=/openhab/userdata/backup --exclude=/openhab/userdata/core* -c -f /openhab/userdata/backup/userdata-YYYY-MM-DDThh-mm-ss.tar /openhab/userdata`