How to disable Xserve power saving while running ESXi I'm running Vmware ESXi 6.5 on an Xserve 3.1 and due to the power saving settings it puts the internal drives to sleep a short while after boot which prevents ESXi from saving settings.

I've tried booting into OSX and disabling there but the problem persists in ESXi. I've also tried the usual SMC and NVRAM resets.

The symptom is a 'disk timeout' for all internal and FireWire attached drives (same for SSD and HDD) after about 15 minutes.

Any suggestions greatly appreciated.
This isn't an answer as such but a fudge/hack that stops the timeout issue by writing regular random data to each drive (static data doesn't appear to work).
Create a shell script as below (mine is called .bmreadloop) on VMFS attached boot storage:
#!/bin/sh

while [ 1 -lt 2 ]
do

&lt;/dev/urandom sed 's/[^[:digit:]]\+//g' | head -c10 &gt; /vmfs/volumes/bonoboBoot/.blah

&lt;/dev/urandom sed 's/[^[:digit:]]\+//g' | head -c10 &gt; /vmfs/volumes/bonoboTwo/.blah

&lt;/dev/urandom sed 's/[^[:digit:]]\+//g' | head -c10 &gt; /vmfs/volumes/bonoboHDD/.blah

&lt;/dev/urandom sed 's/[^[:digit:]]\+//g' | head -c10 &gt; /vmfs/volumes/bonoboThree/.blah

sleep 10

done

Add run it on startup in /etc/rc.local.d/local.sh:
/vmfs/volumes/bonoboBoot/.bmreadloop &gt;&gt; /dev/null &amp;

It's ugly but it works!