Hi list, I need a pointer, please. Something is amiss on my laptop’s setup. When I copy a number of big files (i.e. videos) from one USB device to another, it starts to read the file, then after a few seconds starts to write to the destination and only *after* that file has been completely written, it continues with the next file.
I never knew this behaviour before and my PC does not do this -- it copies
in one continuous go.
I noticed it first in KDE’s transfer speed graph. Then I could reproduce it
with a simple `cp`, but also with rsync and mc. It must be a kernel setting
regarding power saving or writeback size or what have you.
Can you give me a nudge? My sysctl.conf has only one active line besides
some netfilter stuff:
vm.swappiness = 1
(This is an SSD, I don’t even have swap on this machine unless I know I
definitely need it temporarily)
Here is the output of dstat whilst I copied a number of videos from a USB stick
to an external USB 2 harddrive in mc:
----system---- ----total-cpu-usage---- -dsk/total- ----most-expensive----
time |usr sys idl wai hiq siq| read writ| block i/o process
12-01 20:00:49| 1 1 73 25 0 0| 0 34M|
12-01 20:00:51| 1 1 73 25 0 0| 0 37M|
12-01 20:00:53| 3 2 72 22 0 0| 20M 20M|mc 20M 20M
12-01 20:00:55| 5 3 71 21 0 0| 34M 0 |mc 34M 34M
12-01 20:00:57| 5 4 70 21 0 0| 33M 812k|mc 33M 33M
12-01 20:00:59| 1 1 73 25 0 0| 0 36M|
12-01 20:01:01| 1 1 73 25 0 0| 0 34M|
12-01 20:01:03| 3 2 73 22 0 0| 25M 17M|mc 25M 25M
12-01 20:01:05| 4 2 73 21 0 0| 34M 0 |mc 34M 34M
12-01 20:01:07| 4 3 73 21 0 0| 34M 0 |mc 34M 34M
12-01 20:01:09| 2 2 73 23 0 0| 12M 29M|mc 12M 12M
12-01 20:01:11| 2 1 64 34 0 0|4096B 34M|
12-01 20:01:13| 1 1 49 49 0 0| 0 34M|
12-01 20:01:15| 4 2 71 23 0 0| 31M 9381k|mc 32M 32M
12-01 20:01:17| 4 2 73 21 0 0| 34M 17k|mc 34M 34M
12-01 20:01:19| 3 3 73 21 0 0| 34M 3132k|mc 35M 35M
12-01 20:01:20| 3 3 68 26 0 0| 35M 34M|mc 35M 35M
Cheers
--
Gruß | Greetings | Qapla’
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