From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jes Sorensen Subject: Re: deprecating /proc/mdstat Date: Tue, 02 Feb 2016 09:33:31 -0500 Message-ID: References: <56A9102D.4030304@prgmr.com> <87twly1jc7.fsf@notabene.neil.brown.name> <20160128124121.Horde.YKtbZL0CUYKTuEkxLcmmhQ4@www3.nde.ag> <20160128182102.GA23378@kernel.org> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20160128182102.GA23378@kernel.org> (Shaohua Li's message of "Thu, 28 Jan 2016 10:21:02 -0800") Sender: linux-raid-owner@vger.kernel.org To: Shaohua Li Cc: "Jens-U. Mozdzen" , NeilBrown , linux-raid@vger.kernel.org List-Id: linux-raid.ids Shaohua Li writes: > On Thu, Jan 28, 2016 at 12:41:21PM +0100, Jens-U. Mozdzen wrote: >> If there's to be a "new mdstat" in /sys, I'd be fine with that. That would >> help migration for those "old scripts grep'ing /proc/mdstat" you rightfully >> care about. >> >> I suggest to include a file format version information on line 1 >> "/sys/.../mdstat", that way any client parsing such an interface could >> verify the file format first, and bail out if it doesn't support the >> currently presented format. > > All the info you can get from /proc/mdstat can be found in /sys/xxx. There > isn't a central mdstat file in sysfs entry, each sysfs entry only export single > type info. Version info is uncessary, if we need add new info, we'd just add a > new sysfs entry. > > though the /proc/mdstat will not be deprecated soon, it's highly encouraged app > switches to /sys. sysfs entry is easy to parse. And as Neil said, /proc/mdstat > is hard to extend, so new info will likely only appear in sysfs. I think the strong argument for /proc/mdstat is that it's easy for visual inspection, but should not be scripted. I certainly use it quite regularly, but maybe I am just old and lazy :) Cheers, Jes