Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Bug 1166476

Summary: fail to specify the cache mode for qemu-img to bypass the host cache (amend)
Product: Red Hat Enterprise Linux 7 Reporter: Sibiao Luo <sluo>
Component: qemu-kvmAssignee: Ademar Reis <areis>
Status: CLOSED NOTABUG QA Contact: Virtualization Bugs <virt-bugs>
Severity: high Docs Contact:
Priority: high    
Version: 7.1CC: chayang, famz, hhuang, hreitz, juzhang, kwolf, michen, pbonzini, qzhang, rbalakri, virt-maint, xfu
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-11-24 09:05:22 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Sibiao Luo 2014-11-21 04:42:01 UTC 
Description of problem:
From qemu-kvm-1.5.3-35.el7, qemu-img adds the "amend" subcommand option which allows changing image options on existing image files(BZ#1033490). But fail to specify the cache mode for 'qemu-img amend' to bypass the host cache with "amend: invalid option -- 'T'" error.

Version-Release number of selected component (if applicable):
host info:
# uname -r && rpm -q qemu-kvm
3.10.0-205.el7.x86_64
qemu-kvm-1.5.3-79.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1.qemu-img amend -f qcow2 -o compat=0.10 image-1.qcow2 -T none
amend: invalid option -- 'T'
qemu-img version 1.5.3, Copyright (c) 2004-2008 Fabrice Bellard
usage: qemu-img command [command options]
QEMU disk image utility

Command syntax:
  check [-q] [-f fmt] [--output=ofmt] [-r [leaks | all]] [-T src_cache] filename
  create [-q] [-f fmt] [-o options] filename [size]
  commit [-q] [-f fmt] [-t cache] filename
  compare [-f fmt] [-F fmt] [-T src_cache] [-p] [-q] [-s] filename1 filename2
  convert [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-o options] [-s snapshot_name] [-S sparse_size] filename [filename2 [...]] output_filename
  info [-f fmt] [--output=ofmt] [--backing-chain] filename
  map [-f fmt] [--output=ofmt] filename
  snapshot [-q] [-l | -a snapshot | -c snapshot | -d snapshot] filename
  rebase [-q] [-f fmt] [-t cache] [-T src_cache] [-p] [-u] -b backing_file [-F backing_fmt] filename
  resize [-q] filename [+ | -]size
  amend [-q] [-f fmt] [-t cache] -o options filename
......

Actual results:

Expected results:
It should just like qemu-img check/compare/convert/rebase which support specifying the cache mode.

Additional info:
Comment 1 Hanna Czenczek 2014-11-24 09:05:22 UTC 
Hi Sluo,

This is because qemu-img amend modifies the given image. Therefore, it is a destination rather than a source, which means you have to use "-t" to specify the desired caching mode.

Max
Comment 2 Sibiao Luo 2014-11-28 02:54:48 UTC 
(In reply to Max Reitz from comment #1)
> Hi Sluo,
> 
> This is because qemu-img amend modifies the given image. Therefore, it is a
> destination rather than a source, which means you have to use "-t" to
> specify the desired caching mode.
> 
Ok, thanks for your kindly reminds.