One of the paths of a multipath device was brought down for maintenance. This made the filesystem on top of the multipath device to read-only mode.

Issue

• We have physical server that is running multipathd and have successful dual paths to SAN LUNs. Over the weekend the SAN group did fiber maintenance on one of the paths and we experienced the LUN's being mounted read-only and the databases became not operational.
  lvs command shows actual multipath device is being used

lv3  vg01 -wi-ao---- 100.00g         /dev/mapper/mpath-vg01-pv5(0) 
lv4    vg01 -wi-ao----  50.00g           /dev/mapper/mpath-vg01-pv4(72)