From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dan Williams" Subject: Re: Roadmap for md/raid ??? Date: Fri, 19 Dec 2008 10:01:40 -0700 Message-ID: References: <32298247.1229677293053.JavaMail.ngmail@webmail11.arcor-online.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <32298247.1229677293053.JavaMail.ngmail@webmail11.arcor-online.net> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: piergiorgio.sartor@nexgo.de Cc: neilb@suse.de, linux-raid@vger.kernel.org List-Id: linux-raid.ids On Fri, Dec 19, 2008 at 2:01 AM, wrote: > In case of HD failure and resync, the md will start > the operations from the beginning to the end. > On the other hand, it would be wise to sync first the > used blocks (20% in the example) and later the others, > if necessary at all. > Because the array will get faster to a "safe state". > One idea/question is whether we can take advantage of the trim/discard commands added for SSD support to allow filesystems to tell MD which parts of the array it cares about. So for a lightly populated array we can try to treat free space as a second class citizen. -- Dan