Description
Collectd reports /proc/PID/io
fields io_rchar/io_wchar
as ps_disk_octets
type and io_syscr/io_syscw
as ps_disk_ops
type.
The names of these types do not match values they represent.
-
For
io_rchar/io_wchar
data type should be named asps_io_octets
. In Linux, these values represent any I/O of process, not disk I/O only: they include sockets, pipes, console I/O, etc.
Theps_io_octets
type can be added in addition to the existingps_disk_octets
for which values can be obtained fromread_bytes/write_bytes
of /proc/PID/io. These values will be much more correct for reporting asps_disk_octets
than existingio_rchar/io_wchar
. Please note whatread_bytes/write_bytes
is real disk I/O, it does not account file I/O from cache. -
For
io_syscr/io_syscw
correct type should be namedps_io_ops
.
Reported values do not match any real disk ops.
My proposal is to fix these issues.
Related documentation: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/filesystems/proc.txt?id=HEAD#n1558