Self-Service Restore (SSR) - Dateiwiederherstellung in Nutanix VMs
The Nutanix infrastructure allows an administrative user to mount virtual hard disks from so-called VM Recovery Points to the virtual machine directly from the operating system in order to restore individual files from them. This process allows access to both user-created VM Recovery Points and those automatically created by the system. No separate incident to the service desk is required to perform this task.
Procedure
Linux
The necessary command-line tool, ngtcli, is already preinstalled on the LRZ Linux VMs. All commands must be executed with root privileges.
Listing the available VM Recovery Points
ngtcli ssr list-snapshots
Communicating with Nutanix Data Protection Service...
Snapshot Id Disk Labels Logical Drives Create Time
------------ ------------ -------------------- --------------------
180319617 scsi0:0 2026.07.02 02:02 AM
scsi0:1 2026.07.02 02:02 AM
scsi0:2 2026.07.02 02:02 AM
scsi0:3 2026.07.02 02:02 AM
179165234 scsi0:0 2026.07.01 02:01 AM
scsi0:1 2026.07.01 02:01 AM
scsi0:2 2026.07.01 02:01 AM
scsi0:3 2026.07.01 02:01 AM
177579513 scsi0:0 2026.06.30 02:01 AM
scsi0:1 2026.06.30 02:01 AM
scsi0:2 2026.06.30 02:01 AM
scsi0:3 2026.06.30 02:01 AM
175838078 scsi0:0 2026.06.29 02:01 AM
scsi0:1 2026.06.29 02:01 AM
scsi0:2 2026.06.29 02:01 AM
scsi0:3 2026.06.29 02:01 AM
174460821 scsi0:0 2026.06.28 02:01 AM
scsi0:1 2026.06.28 02:01 AM
scsi0:2 2026.06.28 02:01 AM
scsi0:3 2026.06.28 02:01 AM
173267563 scsi0:0 2026.06.27 02:01 AM
scsi0:1 2026.06.27 02:01 AM
scsi0:2 2026.06.27 02:01 AM
scsi0:3 2026.06.27 02:01 AM
In this example, there are 6 VM Recovery Points. Each of the 4 virtual hard disks (scsi0:0 through scsi0:3) of the example VM was taken into account.
Identifying the hard disk from which files are to be recovered
The lsscsi tool is useful for identifying the correct hard disk.
lsscsi
[0:0:0:0] disk NUTANIX VDISK 0 /dev/sda [0:0:1:0] disk NUTANIX VDISK 0 /dev/sdb [0:0:2:0] disk NUTANIX VDISK 0 /dev/sdc [0:0:3:0] disk NUTANIX VDISK 0 /dev/sdd [1:0:0:0] cd/dvd QEMU QEMU DVD-ROM 2.5+ /dev/sr0
Here, we are only looking at the lines of type “disk”. The second and third digits correspond to the SCSI ID (“Disk Label”) from the previous output.
Example: scsi0:2 → [0:0:2:0] → /dev/sdc
Mounting a specific hard disk from a VM Recovery Point
ngtcli ssr attach-disk snapshot-id=173267563 disk-label=scsi0:2
Communicating with Nutanix Data Protection service Verifying if the disk is attached Disk attached successfully, bringing it online Hiding system reserved disks, if any ... Disk attached successfully. Snapshot Id Original Disk Label Attached Disk Label Detach Time ------------ -------------------- -------------------- -------------------- 173267563 scsi0:2 () scsi0:4 (/dev/sde) 2026.07.04 12:14 PM
In this example, the third virtual hard disk, scsi0:2 (usually visible in the system as /dev/sdc), from the VM Recovery Point dated June 27, 2026, was mounted as an additional hard disk, scsi0:4 (/dev/sde), in the system.
Please be sure to note the “Detach Time”!
Hard disks mounted in this way are automatically and forcibly removed from the system after 1 day. This setting cannot be changed!
Therefore, once the recovery process is complete, the hard disk should be unmounted as soon as possible!
Mounting the recovery disk
mount -o nouuid /dev/sde /mnt/
It is essential to specify the mount option nouuid here, since this is a file system that already exists in the VM with the same UUID! However, this is legitimate for recovery purposes, so it must be ignored at this point. If you forget to specify the mount option, you will get an error.
Error message if the mount option nouuid is omitted
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sde, missing codepage or helper program, or other error. dmesg(1) may have more information after failed mount system call.
Restoring the desired files
Now you can restore the relevant files by copying them from the recovery disk to one of the “normal” virtual disks.
Immediately after the process is complete, you should unmount the recovery disk right away.
Unmounting the recovery disk
umount /mnt
List the recovery disks mounted in the VM
ngtcli ssr list-attached-disks
Communicating with Nutanix Data Protection Service... Snapshot Id Original Disk Label Attached Disk Label Detach Time ------------ -------------------- -------------------- -------------------- 173267563 scsi0:2 () scsi0:4 (/dev/sde) 2026.07.04 12:14 PM
Unmounting the recovery disk from the VM
ngtcli ssr detach-disk attached-disk-label=scsi0:4
Unmounting the disk Communicating with Nutanix Data Protection service Verifying if the disk is detached Disk detached successfully.
This completes the recovery process.