Re: ZFS Hangs

From: Kris Kennaway <kris_at_FreeBSD.org>
Date: Sun, 04 Nov 2007 11:12:58 +0100
Peter Schuller wrote:
>> For example, pkg_delete seems to be _extremely_ slow and ^T reports that
>> it is stuck waiting on zfs:(&zio->io_cv) for an unreasonable (IMO) amount
>> of time.
> 
> FWIW, I have seen pkg_install (and possibly other pkg_* tools) being extremely 
> slow seemingly as a result of the active set of files it touches exceededing 
> the amount cached. In particular I had this problem after converting to ZFS, 
> but prior to switching to amd64 and more RAM.
> 
> It would sit and churn on disk I/O forever, entirely seek bound. Tracing the 
> processes showed it traversing the package database over and over (presumably 
> recursively following dependencies or some such). So the same files were 
> touched any number of times. As a result, with too little cached, runtime 
> exploded (it took hours and hours upgrading my desktop using *binary* 
> pre-built packages because the larger packages with a lot of dependencies 
> would take forever to install and delete).

It certainly could be a caching effect but the particular problem you 
were seeing should have been fixed.  Are you still seeing it?

Can the OP report whether e.g. gstat shows disk activity?

Kris
Received on Sun Nov 04 2007 - 09:12:59 UTC

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