On 10/4/23 11:17, Martin K. Petersen wrote:
Hi Bart!
In other words, also for the above example it is guaranteed that
writes of a single logical block (512 bytes) are atomic, no matter
what value is reported as the ATOMIC TRANSFER LENGTH GRANULARITY.
There is no formal guarantee that a disk drive sector
read-modify-write operation results in a readable sector after a
power failure. We have definitely seen blocks being mangled in the
field.
Aren't block devices expected to use a capacitor that provides enough
power to handle power failures cleanly?
How about blacklisting block devices that mangle blocks if a power
failure occurs? I think such block devices are not compatible with
journaling filesystems nor with log-structured filesystems.
Thanks,
Bart.
