Subject: Re: Extension of fsync_range() to permit forcing disk cache flushing
To: None <wrstuden@netbsd.org>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: tech-kern
Date: 12/17/2004 11:20:51
hi,

> Also, you're implicitly assuming that disks don't fail. If an admin has
> taken steps, either in configuration or product choice (good UPS or RAID
> box w/ battery backup for cache), to ensure that writing to the disk drive
> is as good as writing to the media, why penalize him or her by forcing
> cache flushing. And since disks fail (even in RAID), all we have to do is
> make sure that the cache failure probability is less than the disk drive
> failure probability, and then the cache doesn't matter.

while you says "permanent storage" is device and environment dependent,
why do you think flushing disk cache is always needed for your application?

YAMAMOTO Takashi