Hi, It seems that the dead umount process keeps freezing on the same place according to its call trace: umount D C03F93E0 0 15738 15706 (NOTLB) de3bbd68 00000082 d5c53540 c03f93e0 00000040 00000000 cbbba954 00000012 0003640e a7439200 000f5fe6 d5c53540 d5c53690 de3ba000 d8c7ba4c 00000282 d5c53540 c02ea6e0 d8c7ba54 00000001 d5c53540 c01170c0 d8c7ba54 d8c7ba54 Call Trace: [<c02ea6e0>] __down+0x90/0x110 [<c01170c0>] default_wake_function+0x0/0x20 [<c017c511>] __mark_inode_dirty+0xd1/0x1c0 [<c02ea8ab>] __down_failed+0x7/0xc [<e0d1fda0>] .text.lock.balloc+0x8/0x128 [udf] [<e0d25767>] udf_write_aext+0xf7/0x170 [udf] [<e0d1fbac>] udf_free_blocks+0xcc/0x100 [udf] [<e0d2cda4>] extent_trunc+0x124/0x180 [udf] [<e0d2d025>] udf_discard_prealloc+0x225/0x2e0 [udf] [<e0d21301>] udf_clear_inode+0x41/0x50 [udf] [<c017285e>] clear_inode+0xde/0x120 [<c01728df>] dispose_list+0x3f/0xb0 [<c0172a92>] invalidate_inodes+0x62/0x90 [<c015e9ad>] generic_shutdown_super+0x5d/0x140 [<c015f69d>] kill_block_super+0x2d/0x50 [<c015e84d>] deactivate_super+0x6d/0x90 [<c0175e6f>] sys_umount+0x3f/0xa0 [<c014bc8d>] do_munmap+0x13d/0x180 [<c014bd14>] sys_munmap+0x44/0x70 [<c0175ee7>] sys_oldumount+0x17/0x20 [<c0103263>] syscall_call+0x7/0xb If my memory serves me well, I've seen something very similar on alt +sysreq+T in previous freezes Hope it helps finding out what the hell could happen... Thanks, compi