```
I inspected the database’s filesystem and can confirm that the file existed before starting the backup, but after PBM reported the error, the file name changed from `33` to `35`.
Currently, I have a single instance of PSMDB with an initialized replica set.
I can confirm that I created the required role and user according to the documentation.
Here is the connection string I’m using:
```auto
mongodb://pbmuser:secretpwd@mongodb:27017/?authSource=admin
```
My config file
```auto
storage:
type: filesystem
filesystem:
path: /pbm/backup
pitr:
enabled: true
oplogSpanMin: 10
compression: s2
backup:
oplogSpanMin: 0
compression: s2
restore:
batchSize: 500
numInsertionWorkers: 10
mongodLocation: /opt/pbm/bin/mongod
```
Running in container environment, pbm-agent and mongo are in separated containers
---
### Author:  [@Ivan\_Groenewold](https://forums.percona.com/u/Ivan_Groenewold)
#### Post date: [January 27, 2025, 1:38pm UTC](https://forums.percona.com/t/unable-to-take-incremental-physical-backup-using-pbm/36355/2 "2025-01-27T13:38:02Z")
Hi, for physical backups, pbm container needs to access the data volume and also to run under the same user id as mongod. Please see [Run in Docker - Percona Backup for MongoDB](https://docs.percona.com/percona-backup-mongodb/install/docker.html?h=docker#prerequisites) for more details
---
### Author:  [@turbozjeb](https://forums.percona.com/u/turbozjeb)
#### Post date: [January 27, 2025, 1:50pm UTC](https://forums.percona.com/t/unable-to-take-incremental-physical-backup-using-pbm/36355/3 "2025-01-27T13:50:09Z")
Hi, thanks for your answer
Please be informed that these processes run with the same uid
psmdb
```auto
bash-5.1$ id
uid=1001(1001) gid=0(root) groups=0(root),1001(1001)
bash-5.1$ whoami
1001
bash-5.1$ ps aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
1001 1 1.1 0.7 4061508 205272 ? SLsl 13:43 0:01 /opt/mongodb/bin/mongod --config=/opt/mongodb/conf/mongodb.conf
```
pbm
```auto
bash-5.1$ id
uid=1001(1001) gid=0(root) groups=0(root),1001(1001)
bash-5.1$ whoami
1001
bash-5.1$ ps aux
bash: ps: command not found
bash-5.1$ top
bash: top: command not found
bash-5.1$ cat /proc/1/status | grep Uid
Uid: 1001 1001 1001 1001
```
---
### Author:  [@Ivan\_Groenewold](https://forums.percona.com/u/Ivan_Groenewold)
#### Post date: [January 27, 2025, 1:52pm UTC](https://forums.percona.com/t/unable-to-take-incremental-physical-backup-using-pbm/36355/4 "2025-01-27T13:52:38Z")
does PBM container also have read-write access to MongoDB data volume ?
---
### Author:  [@turbozjeb](https://forums.percona.com/u/turbozjeb)
#### Post date: [January 27, 2025, 1:57pm UTC](https://forums.percona.com/t/unable-to-take-incremental-physical-backup-using-pbm/36355/5 "2025-01-27T13:57:35Z")
> [@Ivan\_Groenewold](#):
>
> for physical backups, pbm container needs to access the data volume and also to run under
Shoud I mount mongodb data volume right into pbm container or the read write operations are going to be executed via network?
---
### Author:  [@Ivan\_Groenewold](https://forums.percona.com/u/Ivan_Groenewold)
#### Post date: [January 27, 2025, 2:01pm UTC](https://forums.percona.com/t/unable-to-take-incremental-physical-backup-using-pbm/36355/6 "2025-01-27T14:01:59Z")
it should be mounted
---
### Author:  [@turbozjeb](https://forums.percona.com/u/turbozjeb)
#### Post date: [January 27, 2025, 2:14pm UTC](https://forums.percona.com/t/unable-to-take-incremental-physical-backup-using-pbm/36355/7 "2025-01-27T14:14:51Z")
Jesus Christ, I thought these operation are gonna be established via network, instead of local file system.
Thank you so much for your assistance
Mounting data volume in the same path as it is on mongodb container to the pbm container resolved an issue