Overview
Physical DPOD Cell Members that are required to process high transactions per second (TPS) load include 4 CPU sockets and NVMe disks for maximizing server I/O throughput.
DPOD is using NUMA (Non-Uniform Memory Access) technology to bind each of the Store's logical nodes to specific physical processor, disks and memory in a way that will minimize the latency of persisting data to disks.
Note: If the cell member server does not have 4 CPU sockets or does not have NVMe disks - do not perform the steps in this document.
Enabling NUMA in BIOS
Make sure to enable NUMA in the physical server's BIOS. You may need to consult with the hardware manufacturer documentation on how to achieve that.
Note: The number of NUMA nodes configured in BIOS should be 4 (should match the amount of physical CPU sockets in the server).
Some servers allow increasing the NUMA nodes number (e.g. double the number of CPU sockets), which is not suitable for DPOD.
Once NUMA has been enabled in BIOS, verify that the number of NUMA nodes matches the number of CPU sockets using the following command:
numactl -s | grep cpubind Expected output for 4 CPU sockets cell members: cpubind: 0 1 2 3
Required information
The following table contains the list of installed disks and additional information that must be gathered in order to create the mount points required for federating the DPOD cell member to the cell environment.
Please copy this table, use it during the procedure, and complete the information as you follow the procedure.
The table should have 6 or 9 rows, according to the number of disks installed in your server.
| Disk Bay | Disk Serial | Disk OS Path | PCI Slot Number | NUMA Node (CPU #) |
|---|---|---|---|---|
Installing NVMe Disks in the Correct Disk Bays
Use the hardware manufacturer documentation to find out which disk bay is bound which of the CPUs. CPUs should be numbered from 0 to 3.
You should install the same number of NVMe disks (2 or 3) for CPUs 1, 2 and 3. CPU 0 should not have any NVMe disks bound to it.
Update table: Write down the disk bay and the disk's serial number by visually observing the disk and the bay where it is installed.
Identifying Disk OS Paths
To list the OS path of each disk, execute the following command.
Update table: Write down the disk OS path (e.g.: /dev/nvme0n1) according to the disk's serial number (e.g.: PHLE8XXXXXXC3P2EGN).
nvme -list Expected output: Node SN Model Namespace Usage Format FW Rev ---------------- -------------------- ---------------------------------------- --------- -------------------------- ---------------- -------- /dev/nvme0n1 PHLE8XXXXXXC3P2EGN SSDPE2KE032T7L 1 3.20 TB / 3.20 TB 512 B + 0 B QDV1LV46 /dev/nvme1n1 PHLE8XXXXXXM3P2EGN SSDPE2KE032T7L 1 3.20 TB / 3.20 TB 512 B + 0 B QDV1LV46 /dev/nvme2n1 PHLE8XXXXXX83P2EGN SSDPE2KE032T7L 1 3.20 TB / 3.20 TB 512 B + 0 B QDV1LV46 /dev/nvme3n1 PHLE8XXXXXXN3P2EGN SSDPE2KE032T7L 1 3.20 TB / 3.20 TB 512 B + 0 B QDV1LV46 /dev/nvme4n1 PHLE8XXXXXX63P2EGN SSDPE2KE032T7L 1 3.20 TB / 3.20 TB 512 B + 0 B QDV1LV46 /dev/nvme5n1 PHLE8XXXXXXJ3P2EGN SSDPE2KE032T7L 1 3.20 TB / 3.20 TB 512 B + 0 B QDV1LV46
Identifying PCI Slot Numbers
To list the the PCI slot for each disk OS path, execute the following command.
Update table: Write down the PCI slot (e.g.: 0c:00.0) according to the last part of the disk OS path (e.g.: nvme0n1).
lspci -nn | grep NVM | awk '{print $1}' | xargs -Innn bash -c "printf 'PCI Slot: nnn '; ls -la /sys/dev/block | grep nnn"
Expected output:
PCI Slot: 0c:00.0 lrwxrwxrwx. 1 root root 0 May 16 10:26 259:2 -> ../../devices/pci0000:07/0000:07:00.0/0000:08:00.0/0000:09:02.0/0000:0c:00.0/nvme/nvme0/nvme0n1
PCI Slot: 0d:00.0 lrwxrwxrwx. 1 root root 0 May 16 10:26 259:5 -> ../../devices/pci0000:07/0000:07:00.0/0000:08:00.0/0000:09:03.0/0000:0d:00.0/nvme/nvme1/nvme1n1
PCI Slot: ad:00.0 lrwxrwxrwx. 1 root root 0 May 16 10:26 259:1 -> ../../devices/pci0000:ac/0000:ac:02.0/0000:ad:00.0/nvme/nvme2/nvme2n1
PCI Slot: ae:00.0 lrwxrwxrwx. 1 root root 0 May 16 10:26 259:0 -> ../../devices/pci0000:ac/0000:ac:03.0/0000:ae:00.0/nvme/nvme3/nvme3n1
PCI Slot: c5:00.0 lrwxrwxrwx. 1 root root 0 May 16 10:26 259:3 -> ../../devices/pci0000:c4/0000:c4:02.0/0000:c5:00.0/nvme/nvme4/nvme4n1
PCI Slot: c6:00.0 lrwxrwxrwx. 1 root root 0 May 16 10:26 259:4 -> ../../devices/pci0000:c4/0000:c4:03.0/0000:c6:00.0/nvme/nvme5/nvme5n1
Tip: you may execute the following command to list the details of all PCI slots with NVMe disks installed in the server:
lspci -nn | grep -i nvme | awk '{print $1}' | xargs -Innn lspci -v -s nnn
Identifying NUMA nodes
To list the NUMA node of each PCI slot, execute the following command.
Update table: Write down the NUMA node (e.g.: 1) according to the PCI slot (e.g.: 0c:00.0).
lspci -nn | grep -i nvme | awk '{print $1}' | xargs -Innn bash -c "printf 'PCI Slot: nnn'; lspci -v -s nnn | grep NUMA"
Expected output:
PCI Slot: 0c:00.0 Flags: bus master, fast devsel, latency 0, IRQ 45, NUMA node 1
PCI Slot: 0d:00.0 Flags: bus master, fast devsel, latency 0, IRQ 52, NUMA node 1
PCI Slot: ad:00.0 Flags: bus master, fast devsel, latency 0, IRQ 47, NUMA node 2
PCI Slot: ae:00.0 Flags: bus master, fast devsel, latency 0, IRQ 49, NUMA node 2
PCI Slot: c5:00.0 Flags: bus master, fast devsel, latency 0, IRQ 51, NUMA node 3
PCI Slot: c6:00.0 Flags: bus master, fast devsel, latency 0, IRQ 55, NUMA node 3
Verifying Required Information
Your required information table should be complete by now.
Make sure you have gathered information about all the installed NVMe disks, and that NUMA nodes are between 1 and 3 (and do not include NUMA node 0).
Verifying NVMe Disks Speed
Execute the following command and verify all NVMe disks have the same speed (e.g.: 8GT/s):
lspci -nn | grep -i nvme | awk '{print $1}' | xargs -Innn bash -c "printf 'PCI Slot: nnn'; lspci -vvv -s nnn | grep LnkSta:"
Expected output:
PCI Slot: 0c:00.0 LnkSta: Speed 8GT/s, Width x4, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
PCI Slot: 0d:00.0 LnkSta: Speed 8GT/s, Width x4, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
PCI Slot: ad:00.0 LnkSta: Speed 8GT/s, Width x4, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
PCI Slot: ae:00.0 LnkSta: Speed 8GT/s, Width x4, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
PCI Slot: c5:00.0 LnkSta: Speed 8GT/s, Width x4, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
PCI Slot: c6:00.0 LnkSta: Speed 8GT/s, Width x4, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-