This was originally posted on APC forums on 12/1/2010
We have an DELL/EMC AX-150 storage enclosure (SAN) that relies on a SmartUPS 750 to provide powerfault tolerance. The UPS is used to guarantee that the write cache can be dumped to the drives in the event of a power faillure, without losing any data.
When the UPS fails this information is sent through the USB/serial interface to the SAN and the SAN disables write cache, causing a huge impact in performance.
Our UPS has failed and the write cache is disabled... 😞
While we have replaced the 750 UPS with a 3000 that we had in the stock room (fully functional), it seems that the SAN needs the same UPS (it knows the serial number) and doesn't accept it.
Is there a way to "trick" the 750 so it send "OK status" through the serial port even when the battery is down? we are currently using the 3000 as ups, but we can connect the serial to the 750 if we manage to have it sending OK status.
We also have 3000 spare batteries, so maybe another solution is to plug a 3000 battery in the 750, even when it doesn't fit the box. We could have it connected but out of the enclosure.