Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752939AbbHRPKe (ORCPT ); Tue, 18 Aug 2015 11:10:34 -0400 Received: from zimbra13.linbit.com ([212.69.166.240]:56802 "EHLO zimbra13.linbit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751785AbbHRPKc (ORCPT ); Tue, 18 Aug 2015 11:10:32 -0400 X-Greylist: delayed 428 seconds by postgrey-1.27 at vger.kernel.org; Tue, 18 Aug 2015 11:10:32 EDT Date: Tue, 18 Aug 2015 17:03:19 +0200 From: Lars Ellenberg To: Nick Wang Cc: Philipp Reisner , drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drbd: Support zeroout device instead of initial full sync Message-ID: <20150818150319.GL19958@soda.linbit> Mail-Followup-To: Nick Wang , Philipp Reisner , drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org References: <1950665.2mvfrclfR5@fat-tyre> <1438855462-3757-1-git-send-email-nwang@suse.com> <1438855462-3757-2-git-send-email-nwang@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1438855462-3757-2-git-send-email-nwang@suse.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1269 Lines: 40 On Thu, Aug 06, 2015 at 06:04:22PM +0800, Nick Wang wrote: > Patch set for zeroing out device on both side > instead of initial full sync. Useful for high > latency network environment. > > Implement --zeroout-devices and --discard-devices > for new-current-uuid I still think this does not belong into the kernel at all. I may not yet have properly explained why. This is a lot of stuff to add to the DRBD module, introducing write protocol incompatibility/protocol version bump. For no good reason. you want to create a new drbd, and want to make sure the backing devices are discarded: # blkdiscard /dev/backing and then proceed with # drbdadm create-md ... as normal, and skip the initial sync as documented. You want to grow an existing drbd, you have to grow the backend first, anyways, you can then (if necessary) # blkdiscard --offset $o --length $l /dev/backing, # drbdadm resize ... --assume-clean ... No need to touch either the DRBD module, or the DRBD utils at all. All there already. Lars Ellenberg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/