# Single Database Backup/Restore - Sharded cluster \[Discussion\]

**URL:** <https://forums.percona.com/t/single-database-backup-restore-sharded-cluster-discussion/17397>\
**Category:** Percona Server for MongoDB\
**Tags:** mongodb, closed-no-reply\
**Created:** [September 11, 2022, 1:34pm UTC](https://forums.percona.com/t/single-database-backup-restore-sharded-cluster-discussion/17397 "2022-09-11T13:34:28Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![reab](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@reab](https://forums.percona.com/u/reab)\
**Post date:** [September 11, 2022, 1:34pm UTC](https://forums.percona.com/t/single-database-backup-restore-sharded-cluster-discussion/17397/1 "2022-09-11T13:34:28Z")

</div>

I Have two Percona Mongodb sharded clusters running version Mongodb 4.4 and 4.0.6 versions.  
Currently I’m in the process of migrating Mongodb databases running as a standalone into Percona Sharded cluster using logical backup method.

**What I want to achieve:**

- To be able to backup a single database using Mongodump [This database can be located in a standalone mongodb or in a Percona sharded cluster]
- Restore it to Percona sharded cluster.

But, I am having issue when backing up a single database (Either running individually as a standalone or from other sharded clusters) and restore it into a sharded cluster.

**Steps to reproduce:**  
Take a Backup using Mongodump from either a standalone mongodb or from a sharded cluster.  
Restore it into a Percona sharded clusters running versions 4.4 and 4.0.6

**Error** :

```auto
2022-09-11T12:56:19.636+0000 Failed:: error restoring from archive '/tmp/collection.archive': connection() error occurred during connection handshake:  
auth error: sasl conversation error: unable to authenticate using mechanism "SCRAM-SHA-256": (KeyNotFound) Cache Reader No keys found for HMAC that is valid for time: { ts: 
Timestamp(1662900979, 20003) } with id: 0 2022-09-11T12:56:19.636+0000 305064 document(s) restored successfully. 0 document(s) failed to restore.

```

The user used here has

```auto
mechanisms: ["SCRAM-SHA-1", "SCRAM-SHA-256"]})

```

Note that this issue happens usually only with big databases. But for small dbs mongodump and mongorestore works fine in sharded cluster.