Disks
Disks are virtual versions of physical storage devices, such as SSD and HDD.
Disks are designed for storing data and are attached to VMs. Detaching a disk does not delete its data.
Each disk is located in an availability zone, where it is replicated (unless it is a non-replicated disk) to provide data protection.
Disk types
Nebius AI VMs can use the following disk types:
- Network SSD (
network-ssd
): Fast network drive, which is an SSD based network block storage. - Network HDD (
network-hdd
): Standard network drive, which is an HDD based network block storage. - Non-replicated SSD (
network-ssd-nonreplicated
): Network drive with enhanced performance without redundancy. - High-performance SSD (
network-ssd-io-m3
): Network drive with the same performance characteristics asnetwork-ssd-nonreplicated
, plus redundancy.
Network SSDs, high-performance SSDs, and network HDDs provide sufficient redundancy for reliable data storage and enable continuous read and write operations, even when multiple physical disks fail at the same time. Non-replicated disks do not ensure data security.
If a physical disk hosting a network drive fails, the VM will continue running and will quickly regain full access to its data.
Non-replicated disks and high-performance SSDs
Non-replicated disks and high-performance SSDs outperform network SSDs but have the following limitations:
-
Disk size must be a multiple of 93 GB.
In all calculations, 1 GB = 230 bytes.
Alert
Our recommendation is to avoid using a non-replicated disk as your boot drive. This is because, in case it fails, your virtual machine may become unavailable.
If you need enhanced performance and guaranteed fault tolerance, we recommend using high-performance SSDs.
Attaching and detaching disks
You can only attach each disk to one VM at a time.
To successfully boot a VM up, you will need a boot drive. Optionally, you can then attach more disks to your VM.
Note
Empty disks do not have a file system. If you attach an empty disk, partition and mount it manually. Alternatively, instead of attaching an empty disk, you can create a snapshot of the boot disk and create a VM based on such a snapshot.
When selecting a disk to attach to a VM, you can specify that the disk should be deleted once you delete the VM. This option is available when you create a VM, reconfigure it, or attach a new disk to it.
If a VM had any previously created disks attached, they will be detached when you delete the VM. The data on the disk will be still there, and you will be able to attach the disk to a different VM later.
If you would like to delete a disk with a VM, specify this option when creating the VM, reconfiguring it, or attaching the disk. Such disks will be deleted along with the VM.
Backups
Backups are required to make sure no data is lost if damaged.
To back up disks of any type, use disk snapshots. You can create them manually or set up scheduled snapshots.
You cannot recover a boot disk of an existing VM from a snapshot. However, you can create a new VM to recover a boot disk from a snapshot.
For more information on backing up and restoring VMs, see Backups in Compute Cloud.