From owner-freebsd-newbies Wed Oct 10 1:24:43 2001 Delivered-To: freebsd-newbies@freebsd.org Received: from dark4ce.com (dark4ce.com [194.109.74.197]) by hub.freebsd.org (Postfix) with ESMTP id 4018737B408 for ; Wed, 10 Oct 2001 01:24:39 -0700 (PDT) Received: (from freebsd@localhost) by dark4ce.com (8.11.6/8.11.6) id f9A8ObG37153; Wed, 10 Oct 2001 10:24:37 +0200 (CEST) (envelope-from freebsd) Date: Wed, 10 Oct 2001 10:24:37 +0200 From: Hanno Liem To: Martin Vana Cc: freebsd-newbies@freebsd.org Subject: Re: need to clarify some terms Message-ID: <20011010102437.B30118@dark4ce.com> References: <000701c15162$b2ba8e60$1198e693@kolej.vslib.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <000701c15162$b2ba8e60$1198e693@kolej.vslib.cz>; from martin.vana@vslib.cz on Wed, Oct 10, 2001 at 10:08:08AM +0200 Sender: owner-freebsd-newbies@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org My shot at explaining - any additions/comments welcome :-) On Wed, Oct 10, 2001 at 10:08:08AM +0200, Martin Vana wrote: > can anyone tell me what is Q.O.S. Quality of Service. I've mostly heard it used in a network environment, where it means that different applications/users/protocols have different 'levels' of service. For instance, a packet containing a telephone conversation arriving in time is more important than a download in progress, so the first type of packet should have priority over the second one. > Soft Updates FreeBSD implementation of a journalling file system > Journaling Assuming you mean "journalling file system" here, in the context of the last word. File systems contain data and meta-data. The data are the contents of your files, the meta-data are things like date, file name, but also where on the disk parts (clusters) of the file are stored. In a working environment, 10s or 100s or 1000s of files are opened, closed, modified, written, created etc. at the same time. The OS takes care that the meta-data is updated and reflects the current state of the file system. In the event of a crash, it is possible that meta-data has not been written to disk yet, resulting in an inconsistent file system. Data could get lost this way: for example, the 'content' of a file has been written to disk, but the metadata (location where the file is stored on the disk) hasn't. A journalling file system keeps a 'logfile' of all activities in the file system. Then, when 'half' an operation has been executed, the system can just 'roll back' to a previous state. > MFC (probably verb) ? Microsoft Foundation Classes ? (eludes me at the moment, not so MS minded these days) Han To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-newbies" in the body of the message