In addition to compute power and RAM, the performance of a system is also dependent on the performance of the storage being used. The following three storage tiers are available as part of DCS:
|Ultra fast storage (1)||Primary storage||as much as 5000 (2)||< 2ms||IOPS-intensive applications|
|Fast storage||Primary storage||as much as 700 (2)||< 8ms||Standard system partition|
|Dynamic Storage (3)||Cloud storage||-||-||Backups, big data|
(1) Ultra Fast Storage is available only for DDC, not for DS
(2) With a block size of 8 KB and a R/W ratio of 4:1
(3) Geo-redundant object-storage
Fast or Ultra Fast Storage can be used as the primary system partition with virtual systems in a DDC. In vCD it is possible via API or GUI to attach different storage-profiled virtual disks to a VM. Please pay attention that when doing that, Automated Snapshot functionality restores the individual virtual disks with a significant time delay. That results in time difference of individual hard disk restoration. Therefore, we strongly recommend to use only the same storage tiers for virtual disks connected to a VM.
Ultra Fast Storage is not available for the DS product version. A "primary partition" with a standard 80 GB of Fast Storage is set up per system. If required, a second system partition with a maximum of 1 TB of Fast Storage can be added.
The IOPS values stated are to be regarded as reference values. By default, no mechanisms for effective IOPS limitation are implemented, which explains why an individual system can draw a variety of the stated values in a short amount of time. In the case of excessive use, Swisscom reserves the right to impose limitations for individual systems or vOrgs in order to adjust them to be in line with the reference values. It is your responsibility to use the proper storage tier for the respective intended use. Our experts will be happy to advise you.
Dynamic Storage involves object storage that is geo-redundantly outsourced and optimised for large amounts of data. For example, Dynamic Storage is suitable for backup data or archiving purposes. This storage category can be used in combination with DS and DDC. Dynamic Storage is available to a virtual system not directly as a system partition. There are several possibilties for access Dynamic Storage (virtual drive tool, S3 API, etc.). Please refer here to the DCS Userguide.
Regarding calculation of storage to be billed: There are some elements which are summarized to calculate the amount of storage you are billed at the end of the month. For more information, please refer to the DCS Userguide as well.