Know your disk

How to check read speed

EthStorage node requires the reading IOPS be higher than 160k. See the reason in official document:

Storage Provider FAQ | EthStorage

We can use the fiotool to test the read speed.

1. Install fio

sudo apt update
sudo apt install fio

1. If your server only has one disk, then just run this command to test the reading speed.

fio \
  --name=random-read \
  --ioengine=libaio \
  --direct=1 \
  --rw=randread \
  --bs=4k \
  --size=128g \
  --numjobs=1 \
  --iodepth=1024

1. If your server has more than one disks, you need to determine which disk you need to check first.

   1. Run the first command to find out the disk you want to test, for example: /dev/nvme0n1p2.

   2. Then add --filename=/dev/nvme0n1p2 to the end of the second command.

df -h

fio \
  --name=random-read \
  --ioengine=libaio \
  --direct=1 \
  --rw=randread \
  --bs=4k \
  --size=128g \
  --numjobs=1 \
  --iodepth=1024 \
  --filename=/dev/nvme0n1p2

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How to check NVMe version

1. Run this command to check the PCIe address for your NVMe disk. NVM stands for "Non-Volatile Memory".

lspci | grep "Non-Volatile memory"

You will get an address, such as the "0c:00.0" in the first screenshot. If you get more than one returns, record all of them and check them one by one in next step.

1. Run this command to check the LnkCap speed for your NVMe disk. You need to replace the address "0c:00.0" with the address you get in the first step.

lspci -vvv -s 0c:00.0 | grep LnkCap

LnkCap for a PCIe address

If the Speed is 16GT/s, it indicates a PCIe 4.0 interface, meaning you are utilizing NVMe version 4.

If the Speed is 8GT/s, it indicates a PCIe 3.0 interface, meaning you are utilizing NVMe version 3.