kern/71968: [usb] USB disk triggers swap activity

Walter C. Pelissero walter at
Tue Oct 5 03:00:47 PDT 2004

The following reply was made to PR kern/71968; it has been noted by GNATS.

From: "Walter C. Pelissero" <walter at>
To: freebsd-gnats-submit at,
	Kris Kennaway <kris at>, walter at
Subject: Re: kern/71968: [usb] USB disk triggers swap activity
Date: Tue, 5 Oct 2004 11:58:43 +0200

  > > 	Sony Vaio PCG-XG9, LaCie 160G USB2 disk with UFS2 filesystem
  > > 	mounted automatically by amd.
  > > >Description:
  > > 	When I do a substantial activity on a 160G USB2 disk the
  > > 	system starts an heavy ATA disk activity that looks like
  > > 	swapping because, even though there is still 50MB RAM
  > > 	available, the swap usage jumps up to 14% and then slowly
  > > 	reaches 17%.  Soon, one by one, the programs become
  > > 	irresponsive and the system grinds to a halt (but the ATA
  > > 	activity).  If I don't try it immediately, ssh from another
  > > 	node yields a connection timeout.  Needless to say the USB
  > > 	keyboard and mouse die immediately, while I can still use the
  > > 	trackpad on the laptop.
  > > >How-To-Repeat:
  > > 	dd if=/dev/zero of=/path/to/the/usb/filesystem
  > Does the problem persist with 5.3?
 Sorry for the late answer.  It took me a while to upgrade to
 I don't seem to be able to reproduce the problem under the new system,
 so I'd consider this PR closed.
  > Does 'top' or 'ps' show any unusual activity?
 The swap stats above came indeed from top.  It was indeed unusual for
 me to see a stadily increasing swap allocation while still having 20%
 of RAM untouched.  In the meanwhile no process showed any substantial
 increase in size.
 walter pelissero

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