Mapping LMR disk location

IBM Storage Scale Erasure Code Edition uses storcli (LSI HBA) or perccli (DELL HBA) command to mapping SAS disk slot locations.

The ecedrivemapping command assists the user in generating a file that contains a server’s disk layout.

Before you start, ensure that the following conditions are met:

The server that you designate for mapping drives is populated with the lmr disks you want to map.
The storcli (LSI HBA) or perccli (DELL HBA) command is installed on your selected server node.

Note: For Dell PERC RAID controller, perccli command is a substitute of storcli command.

Mapping lmr disks

The creation of a properly formatted slotmap.yaml file is produced by the ecedrivemapping command.

ecedrivemapping [-h] [--mode {nvme,lmr}]
                              [--slotrange {0-MAX_SLOT} {0-MAX_SLOT}] [--report]
                              [--force] [--version {1,2}]

For example, to create a slotmap.yaml file for lmr disks in slots 5-7, run the following command:

# ecedrivemapping  --mode lmr --slotrange 5 7

Note:

If the --slotrange argument is not specified, the slot range is immediately requested upon execution of the ecedrivemapping command.
If the --mode argument is not specified, the slot range is applied to NVMe and lmr disks.

For each lmr disk found, the identifier LED flashes to display the physical slot location of the lmr disk.

>>> 3 Lmr drives were detected
Now blinking path /c0/e134/s5
>>> Enter the slot number: 5
Now blinking path /c0/e134/s6
>>> Enter the slot number: 6
Now blinking path /c0/e134/s7
>>> Enter the slot number: 7

The slots 5-7 represent the physical slot locations that the corresponding lmr disks are mapped too. A slotmap.yaml file is generated and written to /usr/lpp/mmfs/data/gems/. If a slotmap.yaml file exists, it is saved as a backup file while the newly generated slotmap.yaml file is used.

Verifying slotmap.yaml file

The ecedrivemapping command can be used to summarize the current slotmap.yaml file as follows:

# ecedrivemapping --mode lmr --report
Displaying current storcli-slot to machine-slot map file:
------------------------------------------
Controller: 0
------------------------------------------
  storcli-slot : 5 => machine-slot : 5
  storcli-slot : 6 => machine-slot : 6
  storcli-slot : 7 => machine-slot : 7

The storcli-slot identifier contains the disks that are reported by the storcli command. The machine-slot identifier contains physical slot locations where the disks belong.

For example, the line:

storcli-slot : 5 => machine-slot : 5

means the disk in slot 5 reported by the storcli command is mapped to the physical disk slot location 5.

You can check the slotmap.yaml file in the /usr/lpp/mmfs/data/gems/ directory to see whether it matches the following summary output:

# cat /usr/lpp/mmfs/data/gems/slotmap.yaml
controllers:
    - controller: 0
      eids: 134
      - eidx:
        slots:
        - {storcli-slot: 5,  machine-slot: 5}
        - {storcli-slot: 6,  machine-slot: 6}
        - {storcli-slot: 7,  machine-slot: 7}

The storcli-slots are properly mapped to the machine-slots and are categorized under controller 0. The “eids” represents the enclosure ID number that is verified by the storcli command as follows:

Use the tslsenclslot -ad command for further verification.

# tslsenclslot -ad | mmyfields LocationCode Devices LogicalUnits DiskSerial
J1005749-5 /dev/sda naa.5000C500B8620CCF WFJ0GBST0000E843NRY0
J1005749-6 /dev/sdc naa.5000C500B862FAFB WFJ0GWSD0000J746RSZ9
J1005749-7 /dev/sdb naa.5000C500B8632787 WFJ0GVQA0000E8447RZ5

The output verifies that you have three disks that belong to slots 5-7 with corresponding device names and serial numbers.

The serial numbers of the three disks can be checked with the storcli command that displays a standard output as follows.

# /opt/MegaRAID/storcli/storcli64 /call/eall/sall show all j | grep -E "SN|Detailed Information"
"Drive /c0/e134/s5 - Detailed Information" : {
				"SN" : "WFJ0GBST0000E843NRY0",
"Drive /c0/e134/s6 - Detailed Information" : {
				"SN" : "WFJ0GWSD0000J746RSZ9",
"Drive /c0/e134/s7 - Detailed Information" : {
				"SN" : "WFJ0GVQA0000E8447RZ5"

“Drive /cX/eY/sN” displays the controller (cX), enclosure ID (eY), and slot number (sN). You can verify the serial numbers of slots 5-7 match with the outputs of the tslsenclslot and storcli commands.

Manual authentication of disks and their physical slot locations can be achieved with storcli start locate and strocli stop locate commands.

# /opt/MegaRAID/storcli/storcli64 /c0/e134/s5 start locate
CLI Version = 007.0504.0000.0000 Nov 22, 2017
Operating system = Linux 3.10.0-1127.el7.x86_64
Controller = 0
Status = Success
Description = Start Drive Locate Succeeded.

# /opt/MegaRAID/storcli/storcli64 /c0/e134/s5 stop locate
CLI Version = 007.0504.0000.0000 Nov 22, 2017
Operating system = Linux 3.10.0-1127.el7.x86_64
Controller = 0
Status = Success
Description = Stop Drive Locate Succeeded.

The storcli locate command is used to turn the identifier light of a disk on or off. You can turn on the identifier light of a specific disk with an execution of the “/cX/eY/sN” start locate, where cX, eY, and sN represents the controller, enclosure ID, and slot number. After you verify the physical slot location of the disk, turn off the identifier light with “/cX/eY/sN” stop locate.