DataDomain Randomly filling - Not sure if NetBackup or DataDomain issue
Recently, I've noticed that my DataDomain seems to randomly start filling up, approaching 90%. It has historically been hovering between 73% and 79% full depending on recent cleaning and will hover in that range for weeks. But, from time to time, cleaning will only drop it down by a percent or two, and it will start climbing up into the mid to high 80's over a few days. Its like something builds and hangs there, and then will suddently release the logjam, and drop back down into the mid-70's range, OR the cleanings just stop being effecting for a while. I cant tell where the hangup is. Currently, it is building back up toward 90%. Ive surfed the catalog to see if jobs arent expiring properly, but they appear to be. Any of you seen this behavior before? I'm concerned that it will not return to normal, and I'll have to start manually expiring images.
NBU 18.104.22.168 Windows 2008R2, DataDomain DD670, OS 22.214.171.124