If I have 'dd' running, and want to see stats, the manpage says I can send it
a USR1 signal and it will print "I/O statistics to standard error and then resume
copying". I see something like:
18335302+0 records in 18335302+0 records out 9387674624 bytes
(9.4 GB) copied, 34.6279 seconds, 271 MB/s
The same I/O statistics are displayed at the end of a 'dd' session:
18335302+0 records in
18335302+0 records out
9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s
The man page says I can use the
"status=noxfer" to suppress transfer statistics".
But when I use it the number of records transfered into 'dd'
and out of 'dd' are still displayed. Suppressed is the
sum of the bytes transferred in and out, and the time+rate.
So... it seems status=noxfer isn't fully suppressing the statistics
but more accurately only suppresses the summary, time and rate
stats and not the # records transfered in and out.
Either way... shouldn't it just suppress the whole message,
or what's the point? What switch would one use to suppress
all I/O statistics?