EOS Throughput Speed

Hi,

Please confirm my assumption. It looks trivial, but it should help to understand EOS more generally.

Assumption. The speed (data throughput) of the FST (the EOS system) depends on the slowest disk, the slowest disk in all FSTs connected to the MGM.

Corollary 1. The optimal setup is that all FSTs on the same MGM have all disks of approximately the same speed.

Corollary 2. Adding a few faster disks (for example, SSD besides NL-SAS) to the existing EOS configuration does not increase the EOS throughput speed.

Best regards. Gregor

Hi Gregor,
the speed of the FST is the sum of all disks. If one disk is slower read rstreams served by this disk are slower. When you write or use erasure coding you couple disks, so you should couple disks with the same speed between nodes.

Corollary 1: that is good practice to have the same disks behind FSTs

Corollary 2: yes it increases the speed for the streams served from this disk when reading replicated files. When reading or writing erasure coded files, the slowest disk defines the baseline.

Cheers Andreas.

Hi Andreas,

Thanks a lot for your prompt reply with an upgrade of my assumptions.

Best regards, Gregor