Date: Wed, 21 Apr 2004 13:37:49 -0700 From: steve@Watt.COM (Steve Watt) To: Julian Elischer <julian@elischer.org> Cc: hackers@freebsd.org Subject: Re: how to flush out cache.? Message-ID: <200404212037.i3LKbnpT069214@wattres.Watt.COM> In-Reply-To: Julian Elischer <julian@elischer.org> "Re: how to flush out cache.?" (Apr 21, 13:28)
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On Apr 21, 13:28, Julian Elischer wrote: } Subject: Re: how to flush out cache.? } } On Wed, 21 Apr 2004, Steve Watt wrote: } } > In article <Pine.BSF.4.21.0404211219460.31770-100000@InterJet.elischer.org> you write: } > > } > >Ok so I have an application where I need to } > >reread a file I have just written to ensure that it went to disk } > >correctly.. } > } > What are you hoping to accomplish? There are probably other ways } > to solve the larger problem. } } I thought I was being clear.. } I need to remove all the pages from cache so that a reread of the file } is forced to go to disk. } and I don't want to go read a 2GB dummy file to force the flush.. No, my question is "what are you trying to accomplish with the reread", at a higher level than "I want to know it's on disk". Is there some reason you have for not trusting the hardware? Are you trying to do a database commit protocol? Debugging the storage system? } Someone suggested that I read the file usign 'dump' through the raw } device.. Even doing that doesn't necessarily mean the bits have made it onto the rotating media. There can also be caches in the disk controller, and/or caches on the drive itself. If you're trying for a case where you want to pull the power, unmounting and remounting the filesystem will get it about as close as you can. -- Steve Watt KD6GGD PP-ASEL-IA ICBM: 121W 56' 57.8" / 37N 20' 14.9" Internet: steve @ Watt.COM Whois: SW32 Free time? There's no such thing. It just comes in varying prices...
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