# UnableToWriteStatus error in backup-agent when number of backups grows large

**URL:** <https://forums.foundationdb.org/t/unabletowritestatus-error-in-backup-agent-when-number-of-backups-grows-large/4810>\
**Category:** Using FoundationDB\
**Created:** [March 26, 2025, 11:29am UTC](https://forums.foundationdb.org/t/unabletowritestatus-error-in-backup-agent-when-number-of-backups-grows-large/4810 "2025-03-26T11:29:39Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![sighol](https://sea1.discourse-cdn.com/foundationdb/user_avatar/forums.foundationdb.org/sighol/32/1932_2.png) [@sighol](https://forums.foundationdb.org/u/sighol)\
**Post date:** [March 26, 2025, 11:29am UTC](https://forums.foundationdb.org/t/unabletowritestatus-error-in-backup-agent-when-number-of-backups-grows-large/4810/1 "2025-03-26T11:29:39Z")

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We are running weekly backups of our FDB clusters. In our most long-lived clusters, there is now around 180 backups under the `\xff\x02/backup-agent/tag->uid/`prefix.

For the biggest clusters, we are observing that the backup-agents fail with `UnableToWriteStatus` and `value_too_large`.

```auto
<Event Severity="30" 
       Time="1742394753.496389"
       DateTime="2025-03-19T14:32:33Z"
       Type="UnableToWriteStatus"
       ID="0000000000000000"
       Error="value_too_large"
       ErrorDescription="Value length exceeds limit"
       ErrorCode="2103"
       Machine="10.240.230.198:1"
       ClientDescription="primary-7.1.43-18304034715893442826" />

```

It looks like it is trying to write information about all backups to a single key under `\xff\x02/backupstatus/backup/json/`, and fails because the value is more than 100kb.  
For the affected clusters, the `status json` no longer has any information about backups.  
`cluster.layers.backup` is set to `null`

The backups themselves succeed.

It does not look like the `fdbbackup` command supports deleting backup information from FDB. So far we have created a script to delete the backups from `\xff\x02/backup-agent/tag->uid` and `\xff\x02/backup-agent/uid->config`.

Is this a know issue?

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<div class="post-metadata">

**Author:** ![jzhou](https://sea1.discourse-cdn.com/foundationdb/user_avatar/forums.foundationdb.org/jzhou/32/445_2.png) [@jzhou](https://forums.foundationdb.org/u/jzhou)\
**Post date:** [March 29, 2025, 6:22pm UTC](https://forums.foundationdb.org/t/unabletowritestatus-error-in-backup-agent-when-number-of-backups-grows-large/4810/2 "2025-03-29T18:22:51Z")

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Yes, there is a github issue related this [Backup metadata cleanup · Issue #7367 · apple/foundationdb · GitHub](https://github.com/apple/foundationdb/issues/7367)