From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 08/16] scsi_dh_alua: parse target device id Date: Fri, 14 Feb 2014 13:21:58 +0100 Message-ID: <52FE0A66.6050200@suse.de> References: <1391160600-19652-1-git-send-email-hare@suse.de> <1391160600-19652-9-git-send-email-hare@suse.de> <52FE0793.9040505@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:54537 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752103AbaBNMV7 (ORCPT ); Fri, 14 Feb 2014 07:21:59 -0500 In-Reply-To: <52FE0793.9040505@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Bart Van Assche , James Bottomley Cc: Sean Stewart , Martin George , linux-scsi@vger.kernel.org On 02/14/2014 01:09 PM, Bart Van Assche wrote: > On 01/31/14 10:29, Hannes Reinecke wrote: >> + if (!target_id_size) { >> + /* Check for EMC Clariion extended inquiry */ >> + if (!strncmp(sdev->vendor, "DGC ", 8) && >> + sdev->inquiry_len > 160) { >> + target_id_size =3D sdev->inquiry[160]; >> + target_id =3D sdev->inquiry + 161; >> + strcpy(target_id_str, "emc."); >> + memcpy(target_id_str + 4, target_id, target_id_size); >> + } >> + /* Check for HP EVA extended inquiry */ >> + if (!strncmp(sdev->vendor, "HP ", 8) && >> + !strncmp(sdev->model, "HSV", 3) && >> + sdev->inquiry_len > 170) { >> + target_id_size =3D 16; >> + target_id =3D sdev->inquiry + 154; >> + strcpy(target_id_str, "naa."); >> + memcpy(target_id_str + 4, target_id, target_id_size); >> + } >> + } >=20 > Being able to identify a storage array unambiguously is essential for > the new ALUA device handler algorithm introduced by this patch series= =2E > What if a new storage array is introduced that is not covered by one = of > the heuristics in this patch ? Has it been considered to let storage > array identification occur in user space instead of in the kernel ? >=20 As noted in the other mail, if we cannot decipher the array identifier the whole thing degrades into one pg per sdev. IE we cannot bunch RTPG / STPG for those. The idea here is that those arrays do not have any limitations, so that no special treatment is required. Adding identifiers from userspace are a bit tricky; there is no actual sysfs structure for the device handler. Which we would need if we were to use these tricks. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html