Subject: Re: install/31297
To: Peter <plp@actcom.co.il>
From: Rui Paulo <rpaulo@NetBSD.org>
List: netbsd-bugs
Date: 09/12/2005 02:14:55
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On 2005.09.12 04:09:48 +0300, Peter wrote:
|=20
| On Mon, 12 Sep 2005 rpaulo@netbsd.org wrote:
|=20
| >Synopsis: mounting volumes with -o async speeds up file write=20
| >operations 500% (5 times)
| >
| >State-Changed-From-To: open->feedback
| >State-Changed-By: rpaulo@netbsd.org
| >State-Changed-When: Mon, 12 Sep 2005 00:52:06 +0000
| >State-Changed-Why:
| >
| >Mouting file systems with the async is evil and very dangerous.
|=20
| >>From the mount(8) man page:
| >            async       All I/O to the file system should be done asyn-
| >                        chronously.  In the event of a crash, it is
| >                        impossible for the system to verify the integrit=
y=20
| >                        of
| >                        data on a file system mounted with this option. =
=20
| >                        You
| >                        should only use this option if you have an appli=
ca-
| >                        tion-specific data recovery mechanism, or are=20
| >                        willing
| >                        to recreate the file system from scratch.
| >
| >
| >I think this PR should be closed.
|=20
| Mounting filesystems without -o async while plugged into an UPS is=20
| not so dangerous.

Most of the times, systems that are to be taken to a datacenter after
instalation and configuration were not installed using an UPS, so this
probahly not a very common case.

| Imho not using -o async is dangerous to the installer's health. It=20
| increases the coffee consumption 5 times over the -o async option, and=20
| the blood pressure upon seeing that the data throughput on UDMA2 disks=20
| is only about 150kB/sec without -o async in the conditions shown (many=20
| small files unpacked from tar).

You can make sysinst more silent about that. :-)

| Also during install the worst thing that can happen is that one has to=20
| reinstall. Since installs wipe nearly everything (esp. if the disklabel=
=20
| was edited).

You are not considering the updates made through sysinst.

		-- Rui Paulo

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