From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Message-ID: <23387.29464.233937.89557@quad.stoffel.home> Date: Fri, 27 Jul 2018 15:31:36 -0400 From: "John Stoffel" In-Reply-To: <20180727182658.GI23157@merlins.org> References: <20180726163145.pywehjailovwjv2a@merlins.org> <393829ca-b3ea-77c5-9cc0-9fd12e5eec07@redhat.com> <20180727182658.GI23157@merlins.org> Subject: Re: [linux-lvm] Why use thin_pool_autoextend_threshold < 100 ? Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development Cc: Zdenek Kabelac >>>>> "Marc" == Marc MERLIN writes: Marc> Hi Zdenek, Marc> Thanks for your helpful reply. Marc> On Fri, Jul 27, 2018 at 02:59:28PM +0200, Zdenek Kabelac wrote: >> Dne 26.7.2018 v 18:31 Marc MERLIN napsal(a): >> >Still learning about thin volumes. >> >Why do I want my thin pool to get auto extended? Does "extended" mean >> >resized? >> >> yes extension == resize Marc> Gotcha. Then I don't want to have to worry about my filesystem being resized Marc> multiple times, especially since I'm not sure how it will help. >> man lvmthin. Marc> Thanks. Had read it, but not carefully enough. Marc> So, I just re-read "Automatic extend settings" Marc> I'm still I'm not entirely sure how using extension would help me there. I Marc> can't set it to 10% for all 10 filesystems (50% is minimum). Marc> If I set it to anything less than 100%, it could later that it can block, Marc> and try to extend and resize later, but ultimately I'll still have multiple Marc> filesystems that together exceed the space available, so I can run out. Marc> I'm not seeing how the automatic extend setting is helpful, at least in my case. Marc> Am I missing something? Marc> To be clear, my case is that I will have 10 filesystems in a Marc> place where the same data was in a single filesystem that sadly Marc> I must segment now. More than a few will take more than 1/10th Marc> of the space, but I don't want to have to worry about which ones Marc> are going to use how much as long as all together they stay Marc> below 100% of course. Marc> I don't want to have to manage space for each of those 10 and Marc> have to resize them by hand multiple times up and down to share Marc> the space, hence dm-thin. Why don't you run quotas on your filesystems? Also, none of the filesystems in Linux land that I'm aware of supports shrinking the filesystem while live, it's all a unmount, shrink FS, shrink volume (carefully!) and then re-mount the filesystem. But again, I think you might really prefer quotas instead, unless you need complete logical seperation. John