Fred, > > What is your kernel version? It's 2.6.13-15. Thus, if we have a kernel bug, the newest known leaky version is 2.6.13-15, whereas the oldest fixed version should be 2.6.16.27. As many people run pg on older kernel versions, I would expect many others having memory problems in that case. However, we are going to a dead end. Although I am very sure that I can stop the postmaster without getting the 10 M shmem back, my real problem is worse, because I loose up to 800 M in a continuous way within 14 days. Tom Lane raised the question whether there is more than one bug. Any ideas? Andreas