We have discussion today about the shared volume storage that can also support streaming. And the conclusion was that to support 100 streams (1GB/hour high resolution recordings) played at the same time, we need a high-performance disk RAID array which may cost at least £20k or rather £50k. The calculation is shown below.
Therefore my question is, whether there is any escape from purchasing such an expensive storage? Many thanks, Leslaw And here is the calculation. Take the case of video encoded at 1GB/hour, equal to 300KB/s, stored on a standard disk array with 4KB blocks. A single "viewer" will require the disk to sustain 300/4 = 75 IOPS (I/O operations per second). 100 streams served simultaneously will require 100 times as much I/O, i.e. 7,500 IOPS. A typical 7200rpm disk can sustain at most 150 IOPS (i.e. two streams); a typical 5-disk RAID5 array (e.g. five 2TB 7200rpm disks) would support perhaps 150*4 = 600 IOPS i.e. just 8 streams! So the solution is a high-performance RAID array. _______________________________________________ Matterhorn-users mailing list [email protected] http://lists.opencastproject.org/mailman/listinfo/matterhorn-users
