I was in the process of upgrading my DSM 6.2 NAS with 2 TB drives to DSM 7.1 using 16 TB drives.
I figured that my SAS card was not compatible with drives that size and I needed to have 12 ports. I also learned that DSM 6 was not capable of properly handling large drives.
I got me one of these:
It was plug and play. It was immediately recognized by my system and ARPL. However, I noticed a problem with it.
ARPL reported the 12 ports not contiguously used. It reported ports 1-4, and 17-24 as the ports assigned to the actual physical ports.
I am a bit anal with things like this. I need the ports in the DSM Interface to match the actual ports of my drives in case I need to replace them.
I even noticed that some of the assigned ports didn't even follow the proper order. I would have expected all the ports to be contiguous using the sequential numbers.
So here's how I fixed it:
Step 1. Identify which SATA port is mapped to which physical port
1. I plugged a drive to every physical port
2. I made a list of all the Serial Numbers of each disk and their physical location
3. Loaded DSM and checked in the Storage Manager > HDDs to identify the port actually assigned to each disk
I ended up with the following list:
SATA
PHYSICAL
1
1
2
2
3
3
4
8
5
4
6
5
7
6
8
7
9
9
10
10
11
11
12
12
This helped me identify which ports I needed to switch in order for it to be shown contiguously with the proper numbers that correspond to the actual physical ports.
Step 2. Rebuild the ARPL loader
1. I restarted the NAS and made sure to use the option to make changes to the loader
2. Went into the Command Line options by following this:
3. Added the following as the sata_remap command line option:
sata_remap: 16>3:17>4:18>5:19>6:3>7:20>8:21>9:22>10:23>11
This translates to:
Make port 16 be port 3. Make port 17 be port 4. Make port 18 be port 5. Make port 19 be port 6. Make port 3 be port 7. Make port 20 be port 8. Make port 21 be port 9. Make port 22 be port 10. Make port 23 be port 11.
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NOTE THAT: The SATA ports are given values that start at 0. So, if I had 24 ports, it actually meant ports values were 0-23.
That means that 16>3 is actually changing the DSM reported Drive 17 to be the Drive 4.
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4. Built the loader
5. Booted the loader
Step 3. Confirm Changes
After booting, I checked the reported drives and their serials and that they matched the order in which the physical ports were put.
Hope you find this useful.