Description of problem: Install a RHEL5.5-64 guest and create snapshot chains Base image (RHEL5.5-64.qcow2) -- > sn1 --> sn2 --> sn3 --> sn4 --> sn5 Then rebase sn2 to base image, failed. #qemu-img rebase -b sn3 -F qcow2 -f qcow2 sn5 Version-Release number of selected component (if applicable): kvm-83-172.el5 2.6.18-194.el5 How reproducible: 100% Steps to Reproduce: 1.Install a rhel5.5-64 qcow2 format image and create snapshot chain. 2.Rebase snapshot 3. Actual results: #qemu-img rebase -b sn3 -F qcow2 -f qcow2 sn5 qemu-img: Error while writing to COW image: Permission denied Expected results: Rebase successfully. Additional info:
Does this work with 170? Looks like it's related to Naphtali's read-only support which was added in 171. Adding him to CC.
Re-test in kvm-170, and this issue does not exist. This time I only create sn1,sn2 and sn3, write some file in each snapshot, and then rebase sn3 to sn1. # qemu-img rebase -b sn1 -F qcow2 -f qcow2 sn3 in kvm-170: # qemu-img rebase -b sn1 -F qcow2 -f qcow2 sn3 # qemu-img info sn3 image: sn3 file format: qcow2 virtual size: 80G (85899345920 bytes) disk size: 230M cluster_size: 65536 backing file: sn1 (actual path: sn1) in kvm-172: [root@localhost ~]# qemu-img rebase -b sn1 -F qcow2 -f qcow2 sn3 qemu-img: Error while writing to COW image: Permission denied
Verified on kvm-83-180.el5, passed.
Verified on kvm-83-207.el5, host install tree: RHEL5.6-Server-20101029.0, with the steps in bug description. passed. So, I will change the status to VERIFIED.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0028.html