From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: RE: How to add/drop SCSI drives from within the driver? Date: Fri, 21 Jan 2005 15:58:14 -0800 Message-ID: <1106351894.5932.12.camel@mulgrave> References: <0E3FA95632D6D047BA649F95DAB60E5705A70B74@exa-atlanta> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from stat16.steeleye.com ([209.192.50.48]:27610 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S262624AbVAUX6b (ORCPT ); Fri, 21 Jan 2005 18:58:31 -0500 In-Reply-To: <0E3FA95632D6D047BA649F95DAB60E5705A70B74@exa-atlanta> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Mukker, Atul" Cc: Matt Domsch , "'Salyzyn, Mark'" , "Bagalkote, Sreenivas" , "'brking@us.ibm.com'" , Linux Kernel , SCSI Mailing List , "'bunk@fs.tum.de'" , Andrew Morton , "Ju, Seokmann" , "Doelfel, Hardy" On Fri, 2005-01-21 at 17:11 -0500, Mukker, Atul wrote: > All right! The implementation is complete for this and the driver has > thoroughly gone through testing. Everything looks good except for a minor > glitch. That's good news. > After the new logical drives are created with "- - -" written to the > scsi_host scan attribute, there is a highly noticeable delay before device > names (e.g., sda) appears in the /dev directory. If the management > application tried to access the device immediately after creating new, the > access fails. Putting a 1 second delay helped, but of course this is not a > deterministic solution. > > What are the other possibilities? Well, how about hotplug. The device addition actually triggers a hot plug event already (there's no need to add anything, it's done by the mid-layer), so if you just listen for that, you'll know when the scan has detected a device. James