Repeat this for each volume used for the PostgreSQL Cluster.
If the databases are separated using tablespaces on multiple volumes then each tablespace volume must be mounted to the same location as the original database cluster.
Assuming the volume is already connected to the host and has been discovered proceed by mounting the volume.
If a new volume has been created there could be a need to rescan for new devices. To discover new devices do the following:
Microsoft Windows
In Disk Management select Action and then Rescan Disks.
Linux
To scan for new devices use the rescan-scsi-bus.sh script with the -a qualifier.
rescan-scsi-bus.sh
Microsoft Windows - Press the Win + R keys to open Run, type diskmgmt.msc into Run, and click/tap on OK to open Disk Management. Right click or press and hold on the drive (ex: "MySQL_Base") you want to mount, and click/tap on Change Drive Letter and Paths.
In Change Drive Letters and Paths for <Volume> select the Add... button. Choose either a drive letter or an empty NTFS folder to mount to volume to and select OK when done.
The new drive letter or path should be displayed in the dialog. Select OK when complete to mount the volume.
Linux - In a terminal execute the mount command for the device:
mount /dev/mapper/<device> /var/lib/pgsql
If there is an entry in fstab and the original volume was overwritten with a snapshot then the mount command for the directory can be used without the device:
mount /var/lib/pgsql