OpenVDDK 0.7.4

In short

OpenVDDK 0.7.4 is a drop-in replacement for VMware's VDDK disk library on Linux.

This release adds one thing: it can read disks straight from an ESXi host, including a host that no vCenter manages.

Here you can download the ready-built kits, built from tag v0.7.4.

Why it matters

Before this release, a backup or migration tool that signed in directly to an ESXi host could not open any disk; every open failed with error 1. This affected, for example, a standalone host, or ESXi with the free licence.

0.7.4 reads those disks over NBDSSL (the encrypted network transfer) and NBD (the plain one). Through vCenter, nothing changes.

Situation	0.7.3	0.7.4
Read a disk through vCenter (HotAdd, NBDSSL, NBD)	works	works, unchanged
Read a disk directly from an ESXi host over NBDSSL or NBD	every open fails with error 1	works; the data is the same as through VMware's library
HotAdd on a direct ESXi connection	not available	still not used: the library moves on to the next transport you listed and logs why

Which file to download

File	For whom
openvddk-evalkit-0.7.4-94926da2f764.tar.gz	User kit. For people who run an existing tool, such as nbdkit or virt-v2v, on top of the library. It has the library, the openvddk-admin tool, the header files, one example, ADMIN.md and KNOWN-DIFFERENCES.md.
openvddk-devkit-0.7.4-94926da2f764.tar.gz	Developer kit. For people who write their own program against the library. It has everything in the user kit, plus GUIDE.md, OPERATIONS.md, five examples and a pkg-config file.
sbom.spdx.json	The software bill of materials: every component inside, in SPDX format.
SHA256SUMS	Checksums of the three files above.

Check a download before you use it:

sha256sum -c SHA256SUMS

Not covered

• HotAdd on a direct ESXi connection. Not in this release: on a direct connection the library goes on to the next transport you listed and logs why. Backup products built on VMware's library do use HotAdd on a standalone ESXi host when their proxy VM runs on that same host, and support for that case is being considered for 0.7.5. Until then, use NBDSSL or NBD on a direct ESXi connection. (The kit's KNOWN-DIFFERENCES.md still says no change is planned; that text is corrected in the next build.)
• SAN transport. Not supported, by design: the library never lists, selects or falls back to SAN, and a transport list that names only san fails.
• Local VMDK files (VMware's file transport, a connection without a vCenter or ESXi server). Not planned for 1.0.
• Writing to disks. Read-only by design, as before: write calls fail with VIX_E_FILE_READ_ONLY (11), so restores are not possible.
• Other platforms. Linux x86-64 only (glibc 2.28 or newer); there is no Windows build.

Details

Build

• Built from tag v0.7.4 (commit 94926da2f764) in the pinned AlmaLinux 8 builder (glibc 2.28, gcc 8.5.0, Go 1.26.8), with no network.
• make check, make repro, make sbom, make evalkit and make devkit all passed.

Library

• libvixDiskLib.so.8.0.3, 23,732,320 bytes.
• SHA-256 d39bf157aae96283c8f0ccfadc26b9aec104a5ef9708c4d15cc6945db1dc7daf.
• The same file in both kits and in two independent reproducibility builds.

Admin tool

• openvddk-admin, SHA-256 80453638364c31d4701b3c3b5867fd564a91c3d39a938a6b1ee1612d0ebda01b. It reports 0.7.4 (94926da2f764).

Files

File	Bytes	SHA-256
openvddk-evalkit-0.7.4-94926da2f764.tar.gz	17,494,418	4f50188fcfe9dc8c0e523a05359bee16c12f990f812332548f5b00a4c2252687
openvddk-devkit-0.7.4-94926da2f764.tar.gz	17,506,938	4dac090faa7ccc0cebf0f6c26cb7b8f4ac47fabad7066a5aad24850f4a90f623
sbom.spdx.json	6,635	2cbedc37df3d70ac24f1803fc08851266550eaeccbee482695583bda7c166eb2
SHA256SUMS	298	f70072e6a1706f440efd133526740a99a8931a84309de822316342920d8ca3ce

More

• The full release notes, with what was verified on ESXi 6.7, 7.0 and 8.0.3: docs/RELEASE-NOTES-0.7.4.md.
• Licence: Apache-2.0. See LICENSE, NOTICE and THIRD-PARTY-NOTICES in each kit.