Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 25 Oct 1999 11:02:48 -0600
From:      Greg Lehey <grog@lemis.com>
To:        Dennis Glatting <dennis.glatting@software-munitions.com>, freebsd-current@freebsd.org
Subject:   Re: Strangeness with vinum
Message-ID:  <19991025110248.57032@mojave.worldwide.lemis.com>
In-Reply-To: <Pine.BSF.4.10.9910240838520.4574-100000@btw.plaintalk.bellevue.wa.us>; from Dennis Glatting on Sun, Oct 24, 1999 at 08:53:28AM -0700
References:  <Pine.BSF.4.10.9910240838520.4574-100000@btw.plaintalk.bellevue.wa.us>

next in thread | previous in thread | raw e-mail | index | archive | help
On Sunday, 24 October 1999 at  8:53:28 -0700, Dennis Glatting wrote:
>
> I just want to document some strangeness I see with vinum, in case it
> has been noticed before but not identified, or someone knows a cure.

You should read vinum(4).  It tells you what kind of information I
need for resolving problems.  It also tells you to send the message to
me personally so that I don't miss them.

> I have a Dell XPS D333 with two Adaptec 2940 Ultra SCSI adapters, one
> assigned to fast things and the other to slow things, generally. On
> the slow adapter I have two SEAGATE ST43400N disks I placed under
> vinum. Below is my config file.
>
> drive a device /dev/da3e
> drive b device /dev/da4e
> volume vol1
>  plex org striped 16k

This is too small.  Choose 257 kB unless you have a good reason not
to.  But it has nothing to do with your problem.

>   sd length 2777m drive a
>   sd length 2777m drive b
>
> When I run "iozone -aR" against the volume the entire disks subsystem
> seems to take a pause from time to time when the file sizes get large
> (>= 32 MB).

You don't really want to run iozone.  Use rawio instead.  But of
course you shouldn't get this behaviour.

> By this I mean the pause encompasses both disk controllers.
> Specifically, if I enter a command in a window, such as "ls,"
> against a disk on the fast controller and my cwd is on that
> controller too, then there is a big delay before the disk is listed,
> on the order of 5-10 seconds. My PATH variable does not include any
> devices on the slow controller. The window system still runs fine as
> does the network.

We seem to have buffer management problems in the kernel.  I suspect
what you're seeing here is some kind of yo-yo effect where the system
uses up all its buffers and doesn't recover until a large number have
been flushed.  I've added some additional checks to -CURRENT, but
they're not in -STABLE yet.

> FreeBSD 3.3-STABLE #23: Sat Sep 25 08:27:04 PDT 1999

This isn't really a question for -CURRENT then, is it?  But since
you're here, try the same tests with -CURRENT and see if it happens
there too.

Greg
--
Finger grog@lemis.com for PGP public key
See complete headers for address and phone numbers


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19991025110248.57032>