Hi Paul and all, Thanks for your workaround. I followed exactly with kpartx command, it does works for mkfs when using /dev/mapper/* entries. But there is still no /dev/loop0p* entries created. Do you have any ideas why? I've tried to use a loopback /dev/loop0 to simulate drive type storage pool for KVM virtualization tests, and so that always fails because no /dev/loop0p* entries created. Please shed a light on this. Thanks a lot. --Robin ________________________________ From: Paul Heinlein <heinlein at madboa.com> To: CentOS mailing list <centos at centos.org> Sent: Friday, May 24, 2013 11:05 AM Subject: Re: [CentOS] Failed to create /dev/loop0p* entries for partitions inside loopback devices On Fri, 24 May 2013, Gelen James wrote: > centos 6 failed to create entries under /dev for newly created loopback devices. Any one know why? and how to fix/workaround it? > > The steps to duplicate is pretty simple > > dd if=/dev/zero of=/tmp/deleteme bs=1M count=100 > losetup /dev/loop0 /tmp/deleteme > fdisk /dev/loop0 ## created partitions 1, 2, etc. > fdisk -l /dev/loop0 ## confirmed that the partitions do exist At this point, you need to run "kpartx -a /dev/loop0" (fdisk should have told you so). > mkfs.ext3 /dev/loop0p1 ## failed here [...] kpartx drops partitions into /dev/mapper, so the actual invocation would be mkfs.ext3 /dev/mapper/loop0p1 You can also use partprobe instead of kpartx, but I'm not as familiar with its operation. -- Paul Heinlein heinlein at madboa.com 45°38' N, 122°6' W _______________________________________________ CentOS mailing list CentOS at centos.org http://lists.centos.org/mailman/listinfo/centos