Disk Timeout on xcp virtual block devices

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Dear xcp-ng community,
I try to avoid RO filesystems on Debian because of disks disconnecting for some longer time. My xcp-ng-server uses a central NetApp NAS as its storage for virtual machines, virtual disks, etc.. To avoid the RO behaviour, I try to set the disk timeout to a longer time in /sys/block//device/timeout. The ultimate goal is to achieve this timeout for all disks on all my machines automatically using puppet as automation platform.

What is my Problem?
The following command fails with a Permission denied error
Command: echo 3600 > /sys/block/xvda/device/timeout
Error: cannot create /sys/block/xvda/device/timeout: Permission denied

What have I tried?

• running the command as root
• running the command using puppet
• manually touching the file
• use vim to create the file
• creating a udev rule

After some research I think this issue has something to do with the XCP-ng/Xen storage drivers.

Any help is greatly appreciated!

Thanks in advance