During the course of investigating unusually high latencies with some hardware combinations, it was discovered that disk performance is significantly better on smartarray equipped machines when in HBA mode, as opposed to organizing a JBOD configuration from single-disk RAID0s. Many of the HPs in the RESTBase cluster have already been setup this way, the remaining should be converted as well. The (9) machines in question are:
- restbase1010.eqiad.wmnet
- restbase1012.eqiad.wmnet
- restbase1014.eqiad.wmnet
- restbase2003.codfw.wmnet
- restbase2004.codfw.wmnet
- restbase2001.codfw.wmnet
- restbase2002.codfw.wmnet
- restbase2005.codfw.wmnet
- restbase2006.codfw.wmnet
NOTE: Given the findings of T189057, namely that it may be a mistake to correlate the poor IO performance with SmartArray-equipped HPs, I propose we replace the Samsungs in one of the above HPs with Intel SSDs in order to compare it with restbase2009 (which has 5 HP SSDs).