similar to: Support for NBD block status in nbdkit & qemu NBD client

We had a query yesterday about the VDDK plugin and making it actually obey the weird "Multithreading Considerations" rules in the VDDK documentation (https://vdc-download.vmware.com/vmwb-repository/dcr-public/8f96698a-0e7b-4d67-bb6c-d18a1d101540/ef536a47-27cd-481a-90ef-76b38e75353c/vsphere-vddk-671-programming-guide.pdf) This patch is my attempt to implement this. The idea is that the

As I've spent really too long today investigating this, I want to document this in a public email, even though there's nothing really that interesting here. One thing you find from search for VDD 6.7 / VixDiskLib_QueryAllocatedBlocks issues with Google is that we must be one of the very few users out there. And the other thing is that it's quite broken. All testing was done using

Couple of fixes to return correct data and one nice-to-have clean-up which is not needed. I just find it nicer to read. Martin Kletzander (3): vddk: Use a separate handle for single-link=true vddk: Do not report hole extents to be zero with single-link=true vddk: Eliminate one needless goto plugins/vddk/vddk.c | 48 +++++++++++++++++++++++++++++++++------------ 1 file changed, 36

I believe this roughly implements Nir's proposal here: https://www.redhat.com/archives/libguestfs/2020-August/msg00028.html Unfortunately it doesn't work for me. It actually slows things down quite a lot, for reasons I don't understand. Note the adjustment of the pool-max parameter and how it affects the total time. The results are quite reproducible. $ ./nbdkit -r -U - vddk

In can_extents we test whether the VDDK function VixDiskLib_QueryAllocatedBlocks works before declaring that extents are supported. This VDDK function can fail in several ways but most notable if the server doesn't support querying extents. In this case VDDK raises an error message through the error_function callback, which we turn into a call to nbdkit_error. In most cases this will cause

On 3/20/19 5:11 PM, Richard W.M. Jones wrote: > This uses a new API VixDiskLib_QueryAllocatedBlocks provided in > VDDK >= 6.7. > > Thanks: Martin Kletzander. > --- > plugins/vddk/vddk-structs.h | 15 +++- > plugins/vddk/vddk.c | 138 ++++++++++++++++++++++++++++++++++++ > 2 files changed, 152 insertions(+), 1 deletion(-) > > +static int >

Not sure what version we're up to, but this reimplements extents using the new simpler structure described in this thread: https://www.redhat.com/archives/libguestfs/2019-March/msg00077.html I also fixed most of the things that Eric pointed out in the previous review, although I need to go back over his replies and check I've got everything. This needs a bit more testing. However the

I'm not sure exactly which version we're up to, but let's say it's version 4. I'm a lot happier with this version: - all filters have been reviewed and changed where I think that's necessary - can_extents is properly defined and implemented now - NBD protocol is followed - I believe it addresses all previous review points where possible The "only" thing

I want to post this but mainly for discussion and early review. It's not safe for these patches to all go upstream yet (because not all filters have been checked/adjusted), but if any patches were to go upstream then probably 1 & 2 only are safe. File, VDDK, memory and data plugins all work, although I have only done minimal testing on them. The current tests, such as they are, all

I posted this patch for vdsm, adding NBD APIs: https://gerrit.ovirt.org/c/96079/ The main purpose of these APIs are enabling incremental restore, but they also enable a more efficient rhv-upload via NBD, and importing to thin disks, which is not possible with current solution. The same idea can work for KubeVirt or other targets, minimizing specific target code. Here is how rhv-upload can work

This has already been pushed upstream. I am simply posting these here so we have a reference in the mailing list in case we find bugs later (as I'm sure we will - it's a complex patch series). Great thanks to Eric Blake for tireless review on this one. It also seems to have identified a few minor bugs in qemu along the way. Rich.

This uses a new API VixDiskLib_QueryAllocatedBlocks provided in VDDK >= 6.7. Thanks: Martin Kletzander. --- plugins/vddk/vddk-structs.h | 15 +++- plugins/vddk/vddk.c | 138 ++++++++++++++++++++++++++++++++++++ 2 files changed, 152 insertions(+), 1 deletion(-) diff --git a/plugins/vddk/vddk-structs.h b/plugins/vddk/vddk-structs.h index dbed94a..df88322 100644 ---

When using VIXDISKLIB_FLAG_OPEN_SINGLE_LINK, parent images are not taken into account. However, the data we get from VixDiskLib_QueryAllocatedBlocks() has such granularity that it might return incorrect information. For example when the top image has only one block allocated, we get information about the whole chunk being allocated. This results in the consequent read to return invalid data -

On Thu, Apr 11, 2019 at 06:55:55PM +0100, Richard W.M. Jones wrote: >As I've spent really too long today investigating this, I want to >document this in a public email, even though there's nothing really >that interesting here. One thing you find from search for VDD 6.7 / >VixDiskLib_QueryAllocatedBlocks issues with Google is that we must be >one of the very few users out

I've posted a couple of patches towards the ultimate goal of implementing NBD_CMD_BLOCK_STATUS / base:allocation in nbdkit. Before I can do the final patch I think we need to discuss how this would be exposed to plugins since at the end of the day they need to implement the feature. Background reading: - preparatory patches:

Since it is required, it might as well be magic ;) Signed-off-by: Eric Blake <eblake@redhat.com> --- As written, applies on top of my v3 patch for dlopen; but it would be easy enough to rebase and take this one now even if we aren't sure about the dlopen stuff plugins/vddk/nbdkit-vddk-plugin.pod | 5 ++++- plugins/vddk/vddk.c | 3 ++- tests/test-vddk.sh

We were previously dlopen-ing it in the load() method. This is very early and in particular means that the only possible way to configure where we find the library is through environment variables and not through config parameters. Also it's not necessary as we don't call any functions from the library (such as VixDiskLib_InitEx) until config_complete. This change is neutral refactoring

Proposed small change to the command line of virt-v2v when specifying that you want VDDK mode. Rich.

I couldn't get this to work in the end. This is the latest non-working version. This email documents what doesn't work for the permanent record. The central problem is that VDDK InitEx() appears to dlopen() various of its own plugins. Although I wasn't able to capture exactly what dlopen() command it is running, the plugins cannot be loaded because they rely on the recompiled

That version depends on libexpat.so but does not ship it, and it appears that VMware no longer supports it. Since VDDK 5.5.5 (the next oldest version) dropped support for 32-bit platforms, we can slightly simplify our code by documenting our minimum supported version. Signed-off-by: Eric Blake <eblake@redhat.com> --- v2: scrub for more places to clean up, based on Rich's review of v1