string const read_digest = read (i.from, i.to, total_remaining, total, nanomsg);
LOG_DISK ("Read %1 %2 was %3 on write, now %4", i.from.string(), i.to.generic_string(), i.write_digest, read_digest);
if (read_digest != i.write_digest) {
string const read_digest = read (i.from, i.to, total_remaining, total, nanomsg);
LOG_DISK ("Read %1 %2 was %3 on write, now %4", i.from.string(), i.to.generic_string(), i.write_digest, read_digest);
if (read_digest != i.write_digest) {