Hi! Recently I got access to a tape library and as a side project I try to turn it into something useful. First tests showed that it seems to work fine until it tried to fill a tape: dd if=/dev/urandom of=/dev/st0 ibs=1M obs=512K After around 1.8TiB dd terminates with EIO and in dmesg I see: [535116.858716] st 0:0:0:0: [st0] Sense Key : Medium Error [current] [535116.858720] st 0:0:0:0: [st0] Add. Sense: Write error [535116.874357] st 0:0:0:0: [st0] Sense Key : Medium Error [current] [535116.874370] st 0:0:0:0: [st0] Add. Sense: Write error [535116.874373] st 0:0:0:0: [st0] Error on write filemark. After a reinsert of the tape it works fine again. But any other attempt to fill it results into EIO. Every single time after ~1.8TiB (-/+ 10GiB) have been written. I expected to terminate dd after around 2.5TiB with ENOSPC. First I thought the tape is bad, but even with a new one I face the same issue. Tape is LTO-6 and drive a IBM ULTRIUM-HH6. Is my test wrong? There is a high chance that I'm doing something horrible wrong, I fear I'm a little too young for tape drives. ;-) Maybe the tape drive is faulty but why is it always failing after 1.8TiB? According to the tape library the drive is good and passes all self-tests. And yes, I have a cleaning tape in my library too. -- Thanks, //richard
