Re: [libvirt-users] Whether libvirt can support all backing chain layer are iscsi network disk type

[Peter Krempa]

On Tue, Jan 09, 2018 at 22:12:00 -0500, Meina Li wrote:
> Hi,
> 
> For backing chain that all images are iscsi network disk type , such as
>  iscsi://ip/iqn../0(base image) <-iscsi://ip/iqn../1(active image).
> Currently,  'qemu-img info --backing-chain' command can display correct
> backing file info, but after starting guest with the active image in
> backing chain,  it don't include the related  element in
> dumpxml.
> 
>  So, Whether libvirt can support all backing chain layer are iscsi
> network disk type?

Libvirt can't introspect the backing chain for certain storage
technologies, thus the  elements are missing for them.

Note that the chain should show up as unterminated (not having
 in the last visible layer) which indicates that there
may be images libvirt can't inspect.

This will eventually be solved by keeping the full backing chain in the
XML.


signature.asc
Description: PGP signature
___
libvirt-users mailing list
libvirt-users@redhat.com
https://www.redhat.com/mailman/listinfo/libvirt-users

[libvirt-users] Whether libvirt can support all backing chain layer are iscsi network disk type

[Meina Li]

Hi,

For backing chain that all images are iscsi network disk type , such as
 iscsi://ip/iqn../0(base image) <-iscsi://ip/iqn../1(active image).
Currently,  'qemu-img info --backing-chain' command can display correct
backing file info, but after starting guest with the active image in
backing chain,  it don't include the related  element in
dumpxml.

 So, Whether libvirt can support all backing chain layer are iscsi
network disk type?




Best Regards
Meina Li

On Wed, Jan 3, 2018 at 6:39 AM, Meina Li  wrote:

> Hi,
>
> I am a libvirt qe, I am testing the function about the new location of
> disk auth element (as sub-element of the source element) in Backing Chain
> Management. And I have a questions:
>
> When all the backing chain are iscsi network disk type(no matter if the
> authentication is exist), start the guest ,  it will only has  the top
> level disk in xml and there are no other backingStore in it. The test step
> is below.
>
> So can this function support all backing chain with network disk type
> actually, or only use network authentication as the base image for backing
> chain of file disk type?
>
> Can you help reviewing it? Thanks very much in advance!
>
> Test step:
> 1.  iSCSI server:
>   o- iscsi 
>  [Targets: 2]
>   | o- iqn.2003-01.org.linux-iscsi.localhost.x8664:sn.9cba196611e6
> ... [TPGs: 1]
>   | | o- tpg1 
> .
> [gen-acls, tpg-auth, 1-way auth]
>   | |   o- acls ..
> 
> [ACLs: 0]
>   | |   o- luns ..
> 
> [LUNs: 4]
>   | |   | o- lun0 ..
> .. [fileio/file1 (/tmp/lun1.img)
> (default_tg_pt_gp)]
>   | |   o- portals ..
> ..
> [Portals: 1]
>   | | o- 0.0.0.0:3260 ..
> ...
> [OK]
>   | o- iqn.2003-01.org.linux-iscsi.localhost.x8664:sn.a8d92ebb4ece
> ... [TPGs: 1]
>   |   o- tpg1 
> .. [gen-acls, no-auth]
>   | o- acls ..
> 
> [ACLs: 0]
>   | o- luns ..
> 
> [LUNs: 3]
>   | | o- lun0 ..
> .. [fileio/file3 (/tmp/lun3.img)
> (default_tg_pt_gp)]
>   | o- portals ..
> ..
> [Portals: 1]
>   |   o- 0.0.0.0:3260 ..
> ...
> [OK]
>
> 2. Set iscsi secret.
> # cat iscsi-secret.xml
> 
> iSCSI secret
> 
> libvirtiscsi
> 
> 
> # virsh secret-define iscsi-secret.xml
> Secret 47bd2f3e-023f-44ba-85a3-e8fa7f16ff23 created
> # MYSECRET=`printf %s "redhat" | base64`
> # virsh secret-set-value 47bd2f3e-023f-44ba-85a3-e8fa7f16ff23 $MYSECRET
> Secret value set
>
> 3. Create backing chain.
> # qemu-img create -f qcow2 -b iscsi://redhat:redhat@10.66.7.
> 27:3260/iqn.2003-01.org.linux-iscsi.localhost.x8664:sn.9cba196611e6/0
> iscsi://10.66.7.27:3260/iqn.2003-01.org.linux-iscsi.localhost.x8664:sn.
> a8d92ebb4ece/0 -o backing_fmt=qcow2
>
> 4. Start guest.
> # qemu-img info iscsi://10.66.7.27:3260/iqn.2003-01.org.linux-iscsi.
> localhost.x8664:sn.a8d92ebb4ece/0 --backing-chainimage: json:{"driver":
> "qcow2", "file": {"lun": "0", "portal": "10.66.7.27:3260", "driver":
> "iscsi", "transport": "tcp", "target": "iqn.2003-01.org.linux-iscsi.
> localhost.x8664:sn.a8d92ebb4ece"}}
> file format: qcow2
> virtual size: 5.0G (5368709120 <0536%20870%209120> bytes)
> disk size: unavailable
> cluster_size: 65536
> backing file: iscsi://redhat:redhat@10.66.7.27:3260/iqn.2003-01.org.linux-
> iscsi.localhost.x8664:sn.9cba196611e6/0
> backing file format: qcow2
> Format specific information:
> compat: 1.1
> lazy refcounts: false
> refcount bits: 16
> corrupt: false
>
> image: json:{"driver": "qcow2", "file": {"lun": "0", "portal": "
> 10.66.7.27:3260", "driver": "iscsi", "transport": "tcp", "user":
> "redhat", "password": "redhat", "target": "iqn.2003-01.org.linux-iscsi.
> localhost.x8664:sn.9cba196611e6"}}
> file format: qcow2
> virtual size: 5.0G (5368709120