2TS - 2nd Tier Storage
Low-cost data storage with good reliability and availability
MSD IT 2nd Tier storage is a data storage service intended for less mission-critical data such as experimental results files and longer-term storage
MSD IT 2nd Tier Storage for larger data sets, offers a low-cost alternative to purchasing additional space on our existing high-availability storage. Utilising generic components and open-source technologies, we are now able to offer basic reliability and large-scale storage at relatively low cost. Where raw capacity is the main requirement, rather than high availability or longer-term daily file versioning, 2TS aims to be a cost-effective solution.
Our high-availability data is mirrored synchronously – in real time as it is created, modified or deleted – to an identical system on another of our sites. To reduce the cost, and for rapid disaster recovery, 2TS data is backed up overnight to disk stores on another site. Although the service is offered using the same virtual server infrastructure, unlike the high-availability service, there will be occasional downtime outside of standard UK office hours for routine server maintenance *.
In both cases, the filestore is deployed over redundant disk arrays in a RAID 6 configuration, which offers good protection against multiple disk failures. The filestore will be made available over our standard MSD IT networked file system, which gives us the ability to rapidly recover from any server failures.
Whilst our high-availability filestore is backed up daily to our own backup system, with the ability to recover a file version from any day within the previous year, in order to keep the cost of the 2TS system low, 2TS filestores are backed up each day not only to the University central backup service (which keeps the most recent version of a file and just one prior to that), but also to our own internal backup system with a 30 day retention limit. This means the ability to recover a file version from any day within the previous month. For relatively static experimental results data, this will generally be sufficient and acceptable.
Future enhancements to the service will include the ability to migrate data to offline media (tape) by arrangement for even longer term storage and archiving of data.
2TS data storage (per terabyte): £150 per annum **
* Actual uptime figures are expected to be around 99.9% - or 10 minutes of downtime per week. Recovery time to return an individual 2TS filesystem to functionality are expected to be within 3 hours. However in the case of a serious disaster situation in which many or all filestores need to be restored it is not possible to estimate how long it will take to recover an individual filestore. It is assumed that users understand that data stored on 2TS should not be that which must be always immediately accessible
** Charges are applied per annum (or pro rata for the remainder of the University financial year) in advance, per terabyte or part-terabyte requested, with a minimum capacity charge of 1 terabyte (1024GB). In some cases a discount may be given on annual renewal to reflect average disk capacity actually used in the previous year.