Hi, I just tried to benchmark nilfs and then the file system and benchmark process got stuck. dmesg output is attached. The problems start with nilfs_sufile_do_cancel_free: segment 0 must be clean nilfs_sufile_do_cancel_free: segment 1 must be clean NILFS warning (device sdb1): nilfs_clean_segments: segment construction failed. (err=-28) I'm using Kernel 2.6.33 (Debian 2.6.33-1~experimental.2) nilfs-tools 2.0.16 (Debian 2.0.16-1) The processes are unkillable and the file system cannot be unmounted. The machine will be reset when I get back in physical range on Wednesday and the stuck file system will be removed. If there is anything I can do remotely to help you debug that problem before the file system is gone, let me know. The file system got into this state after writing several times the capacity of the file system, creating a single file until the file cannot be extended any more. # df -k /dev/sdb1 Filesystem 1K-blocks Used Available Use% Mounted on /dev/sdb1 136716284 136372220 0 100% /stxxl/sdb Can't do a ls on the file systen, gets stuck as well. Please keep me CCed, I'm not on the list. Andreas