From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christophe Varoqui Subject: Re: Adding/removing multi-pathed disk partitions Date: Thu, 17 Feb 2005 23:38:40 +0100 Message-ID: <42151CF0.90709@free.fr> References: Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids goggin, edward wrote: >Should one be using the multi-path device-mapper mapped device >name or one of the SCSI target device names for the whole disk >device when modifying a SCSI disk's partition table with fdisk(8)? > >If the former, drivers/block/ioctl.c:blkdev_reread_part() >currently returns EINVAL since the mapped device is not >partitionable. I can't imagine the recommendation is the >latter, since there is no mechanism in place to synchronize >the kernel's partition table handling amongst multiple target >devices. > >-- > As discussed earlier, one face of this problem is that kpartx does buffered reads to grab the on-disk partition table, leading to situations where kpartx ->fdisk -> kpartx sequence does not garanty partitons-to-maps layout will reflect reality. To address this particular problem, do you think adding O_DIRECT to the open() call in kpartx.c would be enough ? Regards, cvaroqui -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel