access to hard drives is "blocked" by writes to a flash drive

[Edward Tomasz Napierała]

Wiadomość napisana przez deeptech71 w dniu 2 mar 2013, o godz. 18:29:
> When one of my flash drives is being heavily written to; typically by ``svn update'' on /usr/src, located on the flash drive; the following can be said about filesystem behavior:
> 
> - ``svn update'' seems to be able to quickly update a bunch of files, but is then unable to continue for a period of time. This behavior is cyclical, and cycles several times, depending on the amount of updating work to be done for a particular run of ``svn update''.
> - Access to any filesystem, whether on the said flash drive or not, seems to be hindered a lot, typically during the said "unable to continue" time. Reading of a file on a hard drive was once delayed for more than 10 seconds. Seemingly as a consequence, the starting of top(1) is also typically delayed.

When that happens, could you do "ps axl" and see the WCHAN column
for the affected processes?  Is it "wdrain"?

-- 
If you cut off my head, what would I say?  Me and my head, or me and my body?