From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: Date: Thu, 17 May 2012 18:00:09 +0200 From: cinap_lenrek@gmx.de To: 9fans@9fans.net In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Subject: Re: [9fans] Thinkpad T61 Installation Experience Topicbox-Message-UUID: 91b66978-ead7-11e9-9d60-3106f5b1d025 no. lets look at a cwfs config. filsys main c(/dev/sdC0/fscache)(/dev/sdC0/fsworm) filsys dump o filsys other (/dev/sdC0/fsother) main is composed from fscache and fsworm. the cache contains the current working set of blocks. when data is requested and its not in the cache, it is read from the worm and copied to the cache. when you write new files, they are allocated in the cache. every day, the filesystem runs a dump process wich copies the blocks that are in the cache but not written to worm (dirty blocks) to the worm. and then flags them as dumped so they can be replaced for other data in the cache. its like a write cache to accumulate changes before they get written to stable storage (worm). only blocks that are new or got modified are dumped. this is like a incremental backup. just that its not just backup, its the main storage. just read the fs paper erik linked. it explains it mutch better and in more detail. -- cinap