From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nao Nishijima Subject: Re: [-v3 PATCH 0/3] Persistent device name using alias Date: Fri, 02 Sep 2011 21:51:54 +0900 Message-ID: <4E60D16A.8060802@hitachi.com> References: <20110825090359.2288.91057.stgit@ltc197.sdl.hitachi.co.jp> <20110825101602.GI3286@htj.dyndns.org> <4E58C3BD.3000609@hitachi.com> <20110827102655.GJ2632@htj.dyndns.org> <4E58E905.4020704@hitachi.com> <16628.1314734537@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <16628.1314734537@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org To: Valdis.Kletnieks@vt.edu Cc: Tejun Heo , linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, Jens Axboe , James.Bottomley@HansenPartnership.com, dle-develop@lists.sourceforge.net, Masami Hiramatsu , yrl.pp-manager.tt@hitachi.com, kay.sievers@gmail.com List-Id: linux-scsi@vger.kernel.org Hi Valdis, (2011/08/31 5:02), Valdis.Kletnieks@vt.edu wrote: > On Sat, 27 Aug 2011 21:54:29 +0900, Nao Nishijima said: >=20 >> A kernel device names (e.g. sda) is not useful information because i= t >> doesn't always point the same disk at each boot-up time. >=20 > If this is important to you, can't you use a udev rule, similar to wh= at most > distros already stick in 70-persistent-net.rules and 70-persistent-cd= =2Erules? >=20 > (Yes, this *does* involve finding a UUID or label or something on th= e disk > that you can identify as "same entity as last time". As you said, it is able to identify a disk at the expense of checking cost. However to introduce "alias" is an advantage of reducing both the cost and the risk of miss-communication, and it can easily identify it. And also, currently, kernel log and command output do not accord with the device name which a user uses (e.g. by-id, by-uuid). I would try to solve those mismatches using "alias". In other words, I'd like to introduce aliases for integrating the name of devices to control and re= cord. Of course I will modify commands using a device name to use a persisten= t device names. Best regards, --=20 Nao NISHIJIMA Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., YOKOHAMA Research Laboratory Email=EF=BC=9A nao.nishijima.xt@hitachi.com