Subject: Re: install/31297
To: None <>
From: Peter <>
List: netbsd-bugs
Date: 09/12/2005 04:09:48
On Mon, 12 Sep 2005 wrote:

> Synopsis: mounting volumes with -o async speeds up file write 
> operations 500% (5 times)
> State-Changed-From-To: open->feedback
> State-Changed-By:
> 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.

>> 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 integrity of
>                         data on a file system mounted with this option.  You
>                         should only use this option if you have an applica-
>                         tion-specific data recovery mechanism, or are willing
>                         to recreate the file system from scratch.
> I think this PR should be closed.

Mounting filesystems without -o async while plugged into an UPS is 
not so dangerous.

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

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