Unmanaged SAN storage processor (SP)

It could happen that one of the storage processor of your SAN displays as unmanaged in GUI.
This can happen after a SAN reboot and is usually related to the UPS powering this SP.
Since the communication between the UPS and the SAN is broken (not available), the SP goes on unmanaged and disable the cache.
In order to solve this, you'll need to stop the SAN (and everything running on before), stop the UPs, restart the UPS and let it do the check opreations (< 1 minute), and finally start the SAN.
Everything should be ok.

Viewing the Dell Service Tag from Windows

If you ever need to check the Dell Service Tag on a machine from within Windows, run the following command:

wmic bios get serialnumber

To do this remotely you need to add the /node: switch. For example:

wmic /node:<servername> bios get serialnumber

Resizing Samsung hard drives to fit controller size limits

If your hard drives are too large to be managed by your controller (in my case 1.5TB HDD with an adaptec SATA RAID SA2420 card, with 1GB per HDD max.) you can resize them using using the Samsung EsTool available here. All details on the same page.
To resize your disk use the SET MAX ADDRESS feature. After resizing, you will be able to use them with size limited controllers (of course you can restore the initial size if needed).

Delay SAN shutdown on power outage, avoid corrupt databases...

In my case the SAN I have will shutdown immediatly if a power outage is detected : and this cannot be changed.
My hardware : Dell EMC AX150 + APC Smart UPS 750
You cannot delay this shutdown through the NaviSphere software.
This is really annoying since the SAN hosts the Exchange databases (could have been SQL databases too).
When there is a power outage, the Exchange server doesn't have time to shutdown before the SAN turns off.... and this can cause database or logs corrupt...
In order to avoid this and since there is nothing I can parameter, I have added an intermediate UPS as shown below :

SPA and SPB are the 2 power supplies of the SAN

So my servers (connected to another UPS) can shutdown on a power outage (please read the shutdown scripts article) and then once the intermediate UPS battery is low (or you can parameter a delay too) it behaves like a power outage for the SAN+UPS and this one turns off too.