Arch Linux

nhStar

Member

Registered: 2019-06-29

Posts: 1

[Solved] Getting LDMTool to mount Dynamic Disks at startup

I recently installed Arch, having been a Debian/Ubuntu user for years.  Using those distros, most things just kinda worked, but in slow motion.

Due to the nature of my work-flows, I have a triple-boot desktop setup (Linux/Windows/FreeBSD).  The OSes are setup on SSDs, however, I have the need to share large storage amongst them, so I decided to go with MS's Dynamic Disk setup (twin 5G drives in a mirror set).

When setting up my Arch installation, I followed the instructions located at the Dynamic Disks wiki page.  Most of it worked out perfectly, as one would expect.

One frustration that I had, was that, the systemd init would run at start, however, it would not find and create the ldm volumes.  Looking through journalctl I would see the normal ldmtool output but when it normally listed the volumes found/created when run from the command line, only an empty array was diplayed ( a "[ ]" surrounding a carriage return).

The Wiki article gave an example unit file:

/etc/systemd/system/ldmtool.service

[Unit]
Description=Windows Dynamic Disk Mount
Before=local-fs-pre.target
DefaultDependencies=no
[Service]
Type=simple
User=root
ExecStart=/usr/bin/ldmtool create all
[Install]
WantedBy=local-fs-pre.target

After some tinkering, and reading, I changed it to read:

/etc/systemd/system/ldmtool.service

[Unit]
Description=Windows Dynamic Disk Mount
After=local-fs-pre.target
DefaultDependencies=no
[Service]
Type=simple
User=root
ExecStart=/usr/bin/ldmtool create all
[Install]

This caused the ldmtool command to be run after the local-fs-pre.target (since I'm not booting from this mirror), and now I can mount the volume via /etc/fstab

Hope this helps!

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 24,075

Re: [Solved] Getting LDMTool to mount Dynamic Disks at startup

Don't use the boards to post presolved information, add a note to the wiki that one might want to change that line to After= if it isn't the boot disk, detection of volumes is late. That way it can be properly documented and preserved.

Last edited by V1del (2019-07-03 15:06:04)