New install onto a SAS dual path system


New Member
Apr 2, 2021

I'm trying to install the latest PVE onto a host for which ALL disks are dual port SAS units. This system was formerly an Oracle Solaris box hosting ZFS.
The dual ported SAS disks seem to confuse the installer.

I try to make a raid1 array for the boot system (see images) but I get the error "Warning: device '/dev/<device>' is used more than once Please fix ZFS setup first.

I also try to install the PVE onto a PCIe based storage device (see images) but it also fails (using a raid0 config).

Must I create a zfs root pool using a live CD first?

I'm not sure how to proceed.



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So all disks show up twice? The PVE installer does not support multipath so you need to select the second disk manually. From the screenshot I can see that they are both the very same disk, just different by which controller it is visible to the system. That is why it is complaining.

May I ask which ISO you are using to install it? Is it the latest 6.3-1one?
Yes, all disks show up twice.

The PVE installer does not support multipath so you need to select the second disk manually.

I understand, but what does this mean operationally? Does that mean bring in the second disk to complete a raid1 after the install is complete?

How do I manually select the second disk?

Also - the installer is 6.3-1

Last edited:
A good way not to get confused with those double disks is to use dm-multipath. It handles the whole multipathing thing and exposes each physical device under/dev/mapper/<wwn>. Those devices can than be used with zfs or md or whatever as those system should not care about the underlying multipath.
Probably the Proxmox installer is not capable of doing this so I would set this up in a regular Debian install and install Proxmox afterwards.
Debian docs suggest that this is possible:


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