From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryusuke Konishi Subject: Re: Number of CheckPoints Date: Thu, 30 Jul 2009 23:52:14 +0900 (JST) Message-ID: <20090730.235214.104764541.ryusuke@osrg.net> References: <4A711C80.1040500@epoch.com> <20090730.233849.87826385.ryusuke@osrg.net> Reply-To: NILFS Users mailing list Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090730.233849.87826385.ryusuke-sG5X7nlA6pw@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: users-bounces-JrjvKiOkagjYtjvyW6yDsg@public.gmane.org Errors-To: users-bounces-JrjvKiOkagjYtjvyW6yDsg@public.gmane.org To: users-JrjvKiOkagjYtjvyW6yDsg@public.gmane.org, dfuller-ZE272gM1l1AAvxtiuMwx3w@public.gmane.org On Thu, 30 Jul 2009 23:38:49 +0900 (JST), Ryusuke Konishi wrote: > For example, a 32-bit Linux kernel can handle up to 2 ^ 32 blocks. > Since NILFS2 stores 21 checkpoints in a standard 4KB block, 32-bit > nilfs can handle up to > > 90,194,313,215 (= about 90.2 giga) checkpoints > > If we create a checkpoint per 5 seconds, it corresponds to > > 18,038,862,643 seconds = 5,010,795 days = 13,728 years > > So the conclusion is, you know, up to the capacity of your drive ;) I made a miscalculation. 90,194,313,215 checkpoints = 450,971,566,080 seconds = 125,269,879 days = 343,205 years. In either case, the conclustion is the same. Ryusuke