From mboxrd@z Thu Jan 1 00:00:00 1970 From: thornber@redhat.com Subject: Re: Default low water mark threshold for a new thin pool Date: Tue, 5 Feb 2013 12:18:47 +0000 Message-ID: <20130205121846.GB3082@raspberrypi> References: <87ehgv16gf.fsf@in.ibm.com> Reply-To: LVM2 development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <87ehgv16gf.fsf@in.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: lvm-devel-bounces@redhat.com Errors-To: lvm-devel-bounces@redhat.com To: LVM2 development Cc: dm-devel@redhat.com List-Id: dm-devel.ids On Tue, Feb 05, 2013 at 02:30:00PM +0530, M. Mohan Kumar wrote: > > Hello, > > We are adding a lvm2api for creating a thin pool. During thin pool > creation if user does not specify anything for the low water mark > thresold, it would result in 0 and no events will be generated when thin > pool capacity is reaching its full size. An event will be generated. > I am not sure what should be the default low water threshold > percentage. Is there any recommended value for low water threshold value > in dm thin pools? It's very hard to say since it depends on your use case. In general you want to allow dmeventd plenty of time to extend the pool before you run out of space. So if you're seeing a _peak_ provisioning rate of 100meg a minute, I'd set the lwm to about 100meg. It would be nice if LVM could help you through this process. - Joe -- lvm-devel mailing list lvm-devel@redhat.com https://www.redhat.com/mailman/listinfo/lvm-devel From mboxrd@z Thu Jan 1 00:00:00 1970 From: thornber@redhat.com Date: Tue, 5 Feb 2013 12:18:47 +0000 Subject: Default low water mark threshold for a new thin pool In-Reply-To: <87ehgv16gf.fsf@in.ibm.com> References: <87ehgv16gf.fsf@in.ibm.com> Message-ID: <20130205121846.GB3082@raspberrypi> List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, Feb 05, 2013 at 02:30:00PM +0530, M. Mohan Kumar wrote: > > Hello, > > We are adding a lvm2api for creating a thin pool. During thin pool > creation if user does not specify anything for the low water mark > thresold, it would result in 0 and no events will be generated when thin > pool capacity is reaching its full size. An event will be generated. > I am not sure what should be the default low water threshold > percentage. Is there any recommended value for low water threshold value > in dm thin pools? It's very hard to say since it depends on your use case. In general you want to allow dmeventd plenty of time to extend the pool before you run out of space. So if you're seeing a _peak_ provisioning rate of 100meg a minute, I'd set the lwm to about 100meg. It would be nice if LVM could help you through this process. - Joe