similar to: compression method for qcow2?

I know there's lots of functions that can access/modify the internal fs of img or qcow2 through libguestfs. I want to know is there any library can modify the raw/qcow2 image directly in Python? For example, there's function called read_qcow2(), and I can know the content of tmp.qcow2 through the function read_qcow2().

Hi, I ran into a strange behavior with libvirt snapshots. I have some vms running with thin-provisioned qcow2 disk images (libvirt 1.1.3 with fedora 20). * When I create a snapshot on the VM, the qcow file suddenly grows big, somewhat bigger than the maximum size of the disk. * When I delete the snapshot, the allocated disk space is not freed up, the qcow image remains the same size. However, if

After snapshot-delete, the qcow2 image file size doesn't decrease, isn't that a waste of disk space? Would someone please tell me how to decrease the file size when snapshot-delete, if that's possible? The image file name of my virtual machine is d0.qcow As follows: [root at test1 ]# virsh list Id Name State

Hi all, on a fully patched CentOS 7.4 x86-64, I see the following behavior: - when creating a new volumes using vol-create-as, the resulting file is a qcow2 version 2 (compat=0.10) file. Example: [root@gdanti-lenovo vmimages]# virsh vol-create-as default zzz.qcow2 8589934592 --format=qcow2 --backing-vol /mnt/vmimages/centos6.img Vol zzz.qcow2 created [root@gdanti-lenovo vmimages]# file

Hi There, I''ve been trying to get this to work for the last couple of days, but found no information on the internet that would help. Essentially, a tap-ctl opencommand with a qcow2 image does not work (error code 2) and produces the following line in syslog: tap-ctl: tap-err:tap_ctl_open: open failed, err -2 I have attached a shell script that reproduces the problem on my machine. The

Recently we had a try of stubdom, whose general status is good. One issue we found is with aio/sync blktap as backend, disk performance is obviously slower, and there are some IDE kernel error messages (like irq timeout) at boot time. Another issue (not stubdom specific) comes from blktap''s support for QCOW image which is based on a backing file. We never tried this configure

Hi Martin, in the meantime, I've found a solution which I consider at least acceptable: 1. create zfs snapshot of domain disk (/dev/zstore/test-volume) 2. save original XML domain definition 3. create snapshot in libvirt like this: virsh snapshot-create --xmlfile snap.xml --disk-only --no-metadata test-domain snap.xml: <domainsnapshot> <disks> <disk

Hi! Changeset 17913 breaks build on *BSD: block-qcow.c:36:20: error: gcrypt.h: No such file or directory cc1: warnings being treated as errors block-qcow.c: In function ''gen_cksum'': block-qcow.c:160: warning: implicit declaration of function ''gcry_md_hash_buffer'' block-qcow.c:160: error: ''GCRY_MD_MD5'' undeclared (first use in this function)

As I'm new to qemu/kvm, to figure out how networking performance can be improved, I went over the code and took some notes. As I did this, I tried to record ideas from recent discussions and ideas that came up on improving performance. Thus this list. This includes a partial overview of networking code in a virtual environment, with focus on performance: I'm only interested in sending

As I'm new to qemu/kvm, to figure out how networking performance can be improved, I went over the code and took some notes. As I did this, I tried to record ideas from recent discussions and ideas that came up on improving performance. Thus this list. This includes a partial overview of networking code in a virtual environment, with focus on performance: I'm only interested in sending

From: Mark McLoughlin <markmc at redhat.com> We can handle receiving partial csums, so set the appropriate feature bit. Signed-off-by: Mark McLoughlin <markmc at redhat.com> Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> --- drivers/net/virtio_net.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c

Hey When I want to take a snapshot for a Domain by using virDomainSnapshotCreateXML. The Error as below happen: libvir: QEMU error : Requested operation is not valid: Disk '/var/lib/libvirt/images/fedora-qcow.qcow2' does not support snapshotting The snapshot Configuration is : <domainsnapshot> <description>Snapshot of OS install and updates</description>

From: Mark McLoughlin <markmc at redhat.com> hdr->csum_start is the offset from the start of the ethernet header to the transport layer checksum field. skb->csum_start is the offset from skb->head. skb_partial_csum_set() assumes that skb->data points to the ethernet header - i.e. it computes skb->csum_start by adding the headroom to hdr->csum_start. Since

Hi all, I'm using ZFS on Linux block volumes as my VM storage and want to do live migrations between hypervisors. If I create ZFS snapshot of used volume on source host, send it do destination host (zfs send/recv) and then run live migration with VIR_MIGRATE_NON_SHARED_DISK flag, the migration works OK. But this procedure copies the whole disk twice which is a huge downside. The best

Hi, List, I''m trying xl create a pv guest with qcow/qcow2 image, it always fails at libxl_device_disk_local_attach. #xl create pv_config_file libxl: error: libxl.c:1119:libxl_device_disk_local_attach: cannot locally attach a qdisk image if the format is not raw libxl: error: libxl_create.c:467:do_domain_create: failed to run bootloader: -3 disk configuration is: disk=[

I have numerous qcow2 images which need to be reduced in size and have their maximum size (virtual size) reduced. Physical disk space became so low that VMs "auto-paused" themselves, I moved enough images to solve the immediate problem but need to rectify the underlying issue. It seems that qcow[2] files are grown in size such that the data inside of them takes about 50-60% of the

All, is it possible to create a new KVM machine from an existing qcow (v3) image with snapshots? snapshot-list doesn't show them, when using virt-manager 1:1.5.1-0ubuntu1.1 to create the machine. * t-ad5.img: QEMU QCOW Image (v3), 42949672960 bytes chris@cd:/data/md0$ qemu-img snapshot -l t-ad5.img Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1

Hi guys, I had to move to the new laptop week ago and I screw migration of my virtual machines. I recovered my virtual machines on the new laptop (virsh define) using the backed up xml files, but I am missing any file with metadata about snapshots. The original storage is cleaned so I cannot take these files anymore. Using qemu-info I can see my snapshots inside the qcow images, but libvirt

I''ve been using lvm under centos to create the backing store for domUs and although the performance seems acceptable it has some shortcomings. The biggest of which is the LVM bug which prevents me from removing an lv (it says it is still mounted and it definitely isnt). I thought this was just a centos bug but it appears to be evident in debian and ubuntu too and I really can''t

Hi Is it true that the GPLPV drivers is incompatible with QCOW images? The Windows DomU works fine with raw standard "file:/" images, and paravirtualized Linux DomU works fine with QCOW and raw images. If i use QCOW images with my Windows DomU''s i get a stop error: 0x00000007b (inaccessible boot device). It looks like the blkback.3.hda process, that normally starts with