[* See ldmtool update at bottom of this article *] Linux is a great tool for low-level disk work on Windows systems. Booting from a live distribution like Knoppix allows access to powerful tools for partition and file-system resizing like parted, gparted, etc. This can allow resizing of the “system” partition (usually the Windows “C:” drive).
Recent distributions have added NTFS read-write and resize support, but there is still one major disk management tool missing that would be useful for fixing or recovering data from Windows systems with Linux. The “Dymamic Disk” feature is still not supported out-of-the-box with the major distributions. This means that disks which have been converted to “dynamic” in Windows will not be able to be used or manipulated by most Linux systems.
This may be changing in the near future. I recently heard about the LDM (Logical Disk Manager) feature in the Linux kernel. According to the documentation linked below, this feature can be enabled by re-compiling the kernel and enabling the following two options CONFIG_PARTITION_ADVANCED and CONFIG_LDM_PARTITION. I’m not sure why this is not enabled out of the box by popular distros, but maybe they’re waiting for it to be considered “stable”, “safe”, or “vetted”? I wonder how many years we have to wait before the decision makers at Ubuntu or other distributions decide to turn it on?
- ldm.txt Kernel Driver Documentation (kernel.org, dated 30 March 2007)
- ldm.c (kernel change log for ldm driver, updated in 2012)
- Incomplete LDM FAQ (flatcap.org, by LDM driver author)
- LDM Doc Home Page (flatcap.org, Change log shows work in 2012 for doc v0.3)
The LDM (Dynamic Disk) support may not work with all features. The documentation does mention that GPT-partitioned dynamic disks are NOT supported (the default MBR partitioning scheme must be used).
My vote is for full out-of-the-box dynamic disk support for Linux maintenance of Windows disks.
UPDATE March 2014 – Ubuntu 14.04 LTS “Trusty Tahr” scheduled for April 2014 release will provide the new ldmtool as a supported package. Along with corresponding releases of Debian, these appear to be the first out-of-box Linux distributions supporting Windows LDM. Ldmtool makes Linux support of Windows LDM volumes more accessible to end-users (from the command-line). See the following related articles for more:
- ldmtool: accessing Microsoft Windows dynamic disks from Linux (mikas blog)
- GitHub libldm (source code for ldmtool and supporting libraries)
- Windows … (LDM) … with Linux (Christian Hudon answer on stackoverflow.com)