Setting SIOC congestion threshhold using EMC FAST storage tiering

[TheVMinator]

I am trying to determine the proper SIOC congestion threshhold when using EMC FAST storage tiering.  For example, suppose I have a Gold, Siver and Bronze Tier.  My Gold tier has LUNs backed as follows:

40% SSD

40% SAS

30% SATA

What should the congestion threshhold be set to?  Should I leave it at the default of 30ms?  Should it be higher or lower based on what percentage of SSD or SATA drives I have?

Any experiences with this setting on FAST?

[mcowger]

We have guidance on that here:

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CC0QFjAA&url=http%3A%2F%...

[OscarDavey]

EMC Symmetrix Storage in VMware vSphere Environments guide can be really helpful for you check plz page 171 for more details http://www.emc.com/collateral/hardware/solution-overview/h2529-vmware-esx-svr-w-symmetrix-wp-ldv.pdf Best regards hope this helped .

Your Oscar

[Alfredj1204]

I would recommend to monitor the performance of your datastores by checking the "Storage I/O Control Normalized Latency ".

To do so:

• rightclick a datastore / Monitor / Performance
• View: performance
• Time Range: Real time

Have a look at "Storage I/O Control Normalized Latency" values (in microsec), this is the value that is used by SIOC to determine wheter or not to kick in.

If you don't have SIOC enabled yet and don't see the "Storage I/O Control Normalized Latency" graph you need to enable the statistics collection:

• rightmouseclick a datastore / all vcenter actions / Configure Storage I/O Control
• deselect "Disable Storage I/O Control Statistics collection"

We have a Symmetrix with FAST and have a SLA with EMC about maximum latencies and we use those values as tresholds. Gold 10ms, Silver 20ms, Bronze 40ms. Your environment can be different so don't take these values for granted.

Regards,

AlfredJ.