Using backup to disk (B2D) as a backup destination is becoming more and more common. I attribute much of this to the rock bottom prices of disk based storage as well as simplicity. It is much more convenient to point a backup to device A and call it a day, as opposed to tape and rotations etc..
Lets face it, you need to have that backup data available for as long as possible because end users often tell you about lost data when its too late. I cannot count the number of times I have been asked to retrieve files and email from 3 months prior… So retention retention retention.
Using a high capacity NAS with Symantec Backup Exec is a reliable way to achieve consistent backups and retain them for a long time. Several of the clients that I manage use Symantec Backup Exec and a large NAS for daily backups. Even though most of the NAS’ are 1TB and larger, it is not uncommon to run out of disk space when you are trying to achieve maximum backup retention.
When configuring your media set overwrite protection and append rules, it is pretty easy to make a mistake. These mis-configurations often result in media not be reused properly, thereby increasing the space used on the NAS. This will eventually lead to Backup Exec flagging the B2D device as low on space and cause all of your backups to be missed / failed.
At this point your have probably resolved the media set issues, removed the media from your device in Backup Exec, and physically removed the B2D files from your devices. Most likely, you will also notice that Backup Exec still lists the device as low on space. Restarting services and everything else you try will not clear this flag. The way that I clear this warning is actually very simple. Go to the Devices tab, and right click on your device. Click on enabled or online to set the device to disabled or offline. Secondly, right click again and pause the device. Next, right click and unpause. Finally you need to enable / online the device. At this point you should be good to go.