$ sync
$ echo 3 | sudo tee /proc/sys/vm/drop_caches
brings HDD write speed up again. I'm running 16.04 LTS; 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:15 UTC 2016 i686 i686 i686 GNU/Linux. (I observed the same write speed slow down in 14.04 LTS kernel.)
for a work around see post by Volker Siegel Aug 3 '14 at 22:40 in unix.stackexcha nge.com/ questions/ 17936/setting- proc-sys- vm-drop- caches- to-clear- cache :
http://
$ sync vm/drop_ caches
$ echo 3 | sudo tee /proc/sys/
brings HDD write speed up again. I'm running 16.04 LTS; 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:15 UTC 2016 i686 i686 i686 GNU/Linux. (I observed the same write speed slow down in 14.04 LTS kernel.)