vhdx

VHDX, or Virtual Hard Disk v2, is a file format used to store virtual hard disk images. It is an evolution of the VHD format, offering enhanced features and improved reliability. VHDX files are commonly used with Microsoft virtualization technologies, such as Hyper-V.

One of the key advantages of VHDX over its predecessor is its increased storage capacity. VHDX supports virtual disks up to 64 terabytes in size, significantly larger than the 2 terabyte limit of VHD. This scalability is crucial for modern enterprise environments that require large storage volumes for virtual machines.

VHDX also incorporates resilience against data corruption. It employs a more robust logging mechanism and performs writes to the virtual disk in a manner that protects against power failures and system crashes. This means that if a host system experiences an unexpected shutdown, the VHDX file is less likely to become corrupted, ensuring data integrity.

Another significant improvement is performance. VHDX introduces optimizations for storage performance, particularly on modern hardware. It supports features like 4KB sector size, which can improve performance for certain workloads compared to the 512-byte sectors used in VHD.

VHDX files are also more efficient in terms of space utilization. They support dynamic provisioning, meaning the virtual disk file only grows as data is written to it, rather than allocating the full specified size upfront. This can lead to significant space savings, especially when creating many virtual machines. Additionally, VHDX supports a feature called "trim" which allows the underlying physical storage to reclaim unused blocks within the virtual disk, further improving space efficiency.