I cannot find any thing in /var/blobstorage

I want to backup my Plone site but facing problem with the blob storage. The are the necessary files in filestorage but nothing is in blob strorage despite me loading images into plone.

One possibility is that you did a root install and are now trying to view the folder with a user that doesn't have permissions.

The issue was permission. Ensure that the owner of the backup buildout is the same as that for the blobstorage file or the backup script will not be allow to write to blobstorage