Network disks
Network disks are scalable block devices that can be easily transferred between cloud servers. Suitable for scaling server disk space without changing the boot disk. Triple replication of disk volumes ensures high data integrity.
The network drive can be create with the cloud server or set up separately and then create a server from it or connect it to a server as an additional disk.
You can work with network disks in control panel with the help of OpenStack CLI or Terraform.
Features of network drives
- five network disk types with different recommended size limits, throughput values and IOPS limits;
- can be used as the boot (system) disk of a cloud server or the mount as an additional disk;
- You can connect up to 255 network disks to a single cloud server if you use a standard disk with virtio-scsi property (up to 4 if you use ide, up to 26 if you use virtio-blk);
- network drive can unsubscribe;
- can enlarge network drive;
- from a network drive can create an image, snapshot or another disk, set up backups;
- can disk drive between pool segments, projects, and accounts.
Types of network disks
- HDD Basic — HDD disk based on enterprise-class SATA disks. Suitable for storing large amounts of data that do not need to be read or rewritten frequently;
- SSD Basic — SSD disk for applications where high read and write speeds are not required. Throughput and IOPS are higher than the basic HDD;
- SSD Universal — SSD disk, suitable for use as a cloud server boot disk;
- SSD Universal v2 — SSD disk with the ability to change the IOPS limit and without fixed division of the number of read and write operations. Suitable for tasks with uneven load. If you select the maximum number of IOPS, it is suitable for CRM-systems, monitoring systems and for working with big data;
- SSD Fast — SSD NVMe disk with lower response time and faster performance than other types. Suitable for workloads that require high read and write speeds.
Disk types differ in recommended size limits, throughput values, and number of read and write operations. See the table for details Network disk limits.
In different pool segments different disk types are available. You can view the availability of the types in the availability matrix Cloud platform network disks.
You can view the list of IDs and type names in the subsection List of network disk types.
Network disk limits
The maximum size of boot and additional network disks, throughput values, and number of IOPS depend on the disk type.
Disks of the same type in different pool segments can have different limits. For example, if two network disks with SSD Universal type are in different segments (the first disk in ru-1c and the second in ru-8a), their limits will be different.
You can test disk performance.
What affects performance
Different types of disks have different IOPS values — the number of read and write operations per second. File system creation and verification are procedures that require a certain number of reads and writes to the disk. The higher the performance of the disk, the faster these operations are completed.
When a cloud server first starts up, the file system on the system disk is "stretched" to fit the size of the disk. The larger the disk size and the lower its IOPS limits, the longer this process will take — hence the longer the cloud server will take to start up.
The size of the file system affects the time to check its state in case of a server crash. Checking is enabled by default for boot (system) disks of all servers that are created from ready-made images.
List of network disk types
To create network disks through the OpenStack CLI and Terraform, IDs or names are used to create network disks network disk types. IDs and names are different in pool segments.
For example, 94350392-3e5c-4b5a-8a51-873f02af833b — ID, a basicssd.ru-9a — name to create a network disk with the SSD Basic type in the ru-9a pool segment.
You can see list of network disk types in all pool segments tabulated or View a list of network disk types in a specific pool through the OpenStack CLI.
List of network disk types in all pool segments
- Saint Petersburg
- Moscow
- Novosibirsk
- Tashkent
- Almaty
- Nairobi
- ru-3
- ru-1
- ru-9
- ru-2
- ru-7
- gis-1
- ru-8
- uz-1
- uz-2
- kz-1
- ke-1
Here:
ID— The ID of the network disk type;Имя— name network drive type and pool segment in the format ofтип.сегмент_пулаfor examplebasic.ru-9a. Available types:basic— HDD type Basic;basicssd— SSD Type Basic;universal— SSD type Universal;universal2— SSD type Universal v2;fast— SSD type Fast.
View a list of network disk types in a specific pool
-
Check out the list of types:
openstack volume type listExample answer for the ru-9 pool:
+--------------------------------------+-----------------+
| ID | Name |
+--------------------------------------+-----------------+
| 8ab097f3-3ffc-4fc4-9771-01fd512936eb | basic.ru-9a |
| 94350392-3e5c-4b5a-8a51-873f02af833b | basicssd.ru-9a |
| 52666f65-ec91-4c09-ad7e-207d10553e4a | universal.ru-9a |
| 2eab725b-4797-4c34-9e1b-4ad083629608 | universal2.ru-9a|
| a67bd670-633b-4c82-bb91-84058140aa05 | fast.ru-9a |
+--------------------------------------+-----------------+Here:
ID— The ID of the network disk type;Name— name network drive type and pool segment in the format ofтип.сегмент_пулаfor examplebasic.ru-9a. Available types:basic— HDD type Basic;basicssd— SSD Type Basic;universal— SSD type Universal;universal2— SSD type Universal v2;fast— SSD type Fast.
Cost
Network disks are charged at cloud platform payment models.
Each GB of network disks is charged. The cost depends on network drive type and the size and pool segment where it's located.
The size of the network disk can be viewed in control panels: from the top menu, press Products → Cloud servers → section Disks → disk row → column Size.
For SSD Universal v2 network drives, the number of IOPS used is also charged. The maximum number of IOPS per hour is taken into account. The first 2,000 IOPS are free of charge. The number of IOPS can be viewed in control panels: from the top menu, press Products → Cloud servers → section Disks → disk page → tab Settings.
The cost per GB (for all network disk types) and per IOPS (for SSD Universal v2 type disks) can be viewed at selectel.ru.