Ubuntu
linux package

  1. Bug #1208993
  2. Comment #10

Comment 10 for bug 1208993

Revision history for this message
Ubfan (ubfan1) wrote :

The default cache setup on Ubuntu 14.04 (no explicit settings in sysctl.conf) seems to use bytes instead of a ratio:
$ cat /proc/vmstat | egrep "dirty|writeback"
nr_dirty 43
nr_writeback 0
nr_writeback_temp 0
nr_dirty_threshold 169462
nr_dirty_background_threshold 84731

This default is for a system with 8G memory, so are probably too small.

The problem caused by this default settings is slow file copies (10 MB/sec) from a SATA hd to a USB3 (SATA disk).

Using a ratio for the default settings instead of a number of bytes might allow better use of memory for machines with memory to spare.