I am doing some tests with creating and deleting large files in a sles12 installation on our AHV environment. I use an ext4 filesystem and have enabled the trim/discard feature for the filesystem and lvm. But when i delete a large file with random data (5g size) the storage backend of the cluster does not see that the former used storage is now not longer used. I tried fstrim to initiate the cleanup but that doesn´t work. If I write zeros to the file/partition/filesystem then the backend gets backs the storage.
Is trim/discard supported to tell the storage backend that filesystem space is no longer needed or does anybody has experience with such a setup ?
Thank you for your help.
Best answer by JonView original