Description of problem:

While running Backup cycle using Restic plugin on single namespace with 5k pods , with 32MB PVC ,  running BusyBox 

the backup failed on "PartiallyFailed"
the errors from velero 

 time="2023-05-10T19:06:46Z" level=info msg="1 errors encountered backup up item" backup=openshift-adp/backup-restic-busybox-perf-single-5000-pods-cephfs logSource="/remote-source/velero/app/pkg/backup/backup.go:431" name=busybox-perf-single-ns-5000-pods-59 time="2023-05-10T19:06:46Z" level=error msg="Error backing up item" backup=openshift-adp/backup-restic-busybox-perf-single-5000-pods-cephfs error="an empty namespace may not be set during creation" logSource="/remote-source/velero/app/pkg/backup/backup.go:435" name=busybox-perf-single-ns-5000-pods-59 

backup name , CR name "backup-restic-busybox-perf-single-5000-pods-cephfs"

Version-Release number of selected component (if applicable):

OCP : 4.11.7

ODF :  4.11.7 
OADP: 1.2.0-63

Steps to Reproduce:
1. create single namespace with 5k pods using BusyBox with PVC size of 32MB  on ocs-storagecluster-cephfs

2. run a backup CR  on this ns using restic 

Actual results:

PartiallyFailed

Expected results:

Completed