Hello all, I have observed the following behaviour with the crypto mapper and the linear mapper in 2.6.9. Since I have found no explanation I am now asking here. What I have done is the following: 1. Map /dev/hdX (real disk) to /dev/mapper/xx 2. Write to /dev/mapper/xx (with 'dd_rescue /dev/urandom /dev/mapper/xx' or 'cat /dev/urandom /dev/mapper/xx', does not matter). 3. Read from /dev/hdX. The data read from /dev/hdX does not reflect the write to /dev/mapper/xx or only after a lot of data ( > main memory) has been written. Waiting does not help. (After 1 hour still no change.) Note: If I write to /dev/hdX, the change is seen immediately in /dev/mapper/xx. My questions: 1. Does /dev/mapper/xx or /dev/hdX reflect the true state of the data on disk after the above sequence? 2. What is the problem here? Christophe Saout suggested to me that this could be a problem with independent buffers for both devices. If this is the case, then it seems the buffer of /dev/mapper/xx gets notified of changes made via /dev/hdX, but the buffer of /dev/hdX does not get notified of changes made via /dev/mapper/xx. Would this be a bug? Thanks for any insights, I searched the list-archives and the web without result. Arno -- Arno Wagner, Dipl. Inform., CISSP --- CSG, ETH Zurich, wagner@xxxxxxxxxxxxxx GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans