How to Hot Add a DS4243 Shelf - A Quick Guide

IMPORTANT: Please read the “DS4243, DS2246, DS4486, and DS4246 Disk Shelf Installation and Service Guide” and specifically the section “Hot-adding a SAS disk shelf”

In this post, we’ll run through a hot-add of a DS4243 shelf. To illustrate this, below are two visio diagrams of a pair of FAS3270 heads (with IOXMs) - one cabled from top to bottom, and the other cabled bottom to top - with an existing stack of 3 shelves. Whether you’re hot-adding a new shelf to the bottom of a stack or the top (most likely) the procedure is the same. The commands used in this post are mainly for Data ONTAP 7-Mode.

Image: FAS3270AE SAS cabling and one stack of 3xDS4243 shelves (top to bottom)

Image: FAS3270AE SAS cabling and one stack of 3xDS4243 shelves (bottom to top)

Hopefully, the SAS cables from the controllers have been properly labelled (at both ends) like below:

0a/N1 - An/S1
0b/N1 - Bl/S1
0a/N2 - Bn/S1
0b/N2 - Al/S1

Note: The SAS cables will be black and the use of colour here is to hopefully make things clear.

Step-by-Step Walkthrough

1. Rack and stack the shelf
2. Set the shelf ID to the next available consecutive number (13 in the examples above - must be unique across the HA pair), and power cycle
CTRA/B> sasadmin shelf adapter ID
- can be used to verify IDs already in use.

3. CTRA/B> options autosupport.doit “SHELF HOT-ADD”
4. CTRA&B> options disk.auto_assign off (Do on both controllers!)

5. Unplug the “long” cable from the IOM A circle port from the final shelf in the stack
CTRB> storage show disk -p
- should show the A path having gone down on CTRB, the B path should still be up.
6. Plug the cable into the IOM A circle port on the new shelf

7. Unplug the “long” cable from the IOM B circle port from the final shelf in the stack
CTRA> storage show disk -p
- should show the B path having gone down on CTRA, the A path should still be up.
8. Plug the cable into the IOM B circle port on the new shelf

9. Plug in a SAS “daisy chain” cable from the now empty IOM A circle port to the IOM A square port on the new shelf
10. Plug in a SAS “daisy chain” cable from the now empty IOM B circle port to the IOM B square port on the new shelf

11. The ACP cabling is pretty straight forward - just move the two ACP cables from circle ports on the original last shelf in the stack, into the ACP circle ports on the new shelf, and daisy chain from circle to square the remaining ACP ports.
12. Assign disks and enable options disk.auto_assign on as required.
13. CTRA/B> options autosupport.doit “SHELF HOT-ADD DONE”

Note: “Data ONTAP does not always automatically update the disk drive, disk shelf, and ACP firmware on hot-added SAS disk shelves” - please read the “Installation and Service Guide” for more information.

Other Notes

i. There are different ways of doing the above - some will take both “long cables” out, rather than doing one at a time; some will daisy-chain first …

ii. Useful sasadmin commands:

sasadmin expander_map
sasadmin shelf adapter_name
sasadmin expander_map adapter_name

iii. Useful disk commands:

disk show -n
disk assign {disk name}
disk assign -n {number} -o {owner filer}
disk assign all
disk show -v

iv. Useful ACP commands:

acpadmin list_all
storage show acp
options acp.enabled off
options acp.enabled on

v. Verifying firmwares:

storage show disk -a
sysconfig -v
storage show acp

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