Target disk subsystem
In this section we are going to test the target computer’s performance to create a 1 GB file on local storage using the linux dd command. The dd command will create this 1GB file and time the creation process for us. Just be aware that this is a data distructive test. The contents of your local storage device will be erased during the test. Don’t perform this storage bandwidth test on a disk where you can not afford to lose the data.
The hardest step in the process is finding the local storage device name, removing all partitions on the disk, and then creating a new partition for our testing.
First lets find the name of your local storage disk. We will use the lsblk command to locate the linux device name. In the figure below you see the linux device name is sda for a sata attached disk, It has 2 partitions sda1 sda2# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 238.5G 0 disk ├─sda1 8:1 0 512M 0 part /boot/efi └─sda2 8:2 0 238G 0 part / sr0 11:0 1 1024M 0 rom
Below is an example of an NVMe disk. In this case the device name is nume0n1 and the partition numbers are p1 p2 p3 p4.# lsblk NAME MAT:MIN RM SIZE RO TYPE MOUNTPOINT nume0n1 259:0 0 4776 0 disk |-nume0n1p1 259:1 0 100M 0 part |-nume0n1p2 259:2 0 16M 0 part |-nume0n1p3 259:3 0 476.3G 0 part |-nume0n1p4 259:4 0 508M 0 part
For the rest of this section we will assume you have a NVMe drive so we will use that naming convention. So we know the NVMe device name is nume0n1. Lets use the fdisk utility to remove all of the existing partitions on the disk. Don’t forget I mentioned this is a data destructive test.fdisk /dev/nume0n1
Use the d command to remove all of the existing partitions on the disk. Then use the w command to write the blank partition table to disk. You can confirm the partitions are gone with the p command. Now finally create a new partition using the n then p primary, 1 first partition and then pick the defaults for the remainder. Now use the w write command to write the partitions to disk and the q command to quit fdisk. Finally ensure the OS is in sync with the disk by keying in sync twice at the FOS Linux command prompt.
You can confirm your changes my once again using the lsblk command.# lsblk NAME MAT:MIN RM SIZE RO TYPE MOUNTPOINT nume0n1 259:0 0 4776 0 disk |-nume0n1p1 259:1 0 477.6G 0 part
Now that we have our test partition we need to format it. Lets format this nvme first partition using this command.mkfs -t ext4 /dev/nvme0n1p1
The output of this command should look similar to this# mkfs -t ext4 /dev/nvme0n1p1 nke2fs 1.45.6 (20-Mar-2020) Discarding device blocks: done Creating filesysten with 124866880 4k blocks and 31219712 inodes Filesysten UUID: 5652bad-814c-4a2d-811a-fd5fb50a6dc4 Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000 Allocating group tables: done Writing inode tables: done Creating journal (262144 blocks): done Writing superblocks and filesystem accounting information: done
Hang on we are almost done with the setup. The next step is to create a directory mount point and to connect the nvme partition to the directory mount point.mkdir /ntfs mount -t ext4 /dev/nvme0n1p1 /ntfs
Issue the following command to confirm the partition is mounted.df -h Filesystem Size Used Avail Use% Mounted on /dev/root 248M 97M 139M 42% / /dev/nvme0n1p1 477G 26G 452G 6% /ntfs
The line we are looking for is this one. It shows that the device /dev/nvme0n1p1 is connected to the /ntfs path./dev/nvme0n1p1 477G 26G 452G 6% /ntfs
Finally we’ve made it to the benchmarking point. Now we will use the dd command to create a 1GB file on the local disk.dd if=/dev/zero of=/ntfs/test1.img bs=1G count=1 oflag=direct 1+0 records in 1+0 records out 1073741824 bytes (1.1 GB, 1.0GiB) copied, 0.546232 s, 2.0 GB/s
In this case the dd command created the 1GB file in about a 1/2 second at a rate of 2.0 GB/s. This results is withing the expected range.
I can give you a few numbers off the top of my head that are reasonable results.
SATA HDD (spinning disk) 40-90MB/s
SATA SSD 350-520MB/s
If your results are within the above ranges for the selected storage device this part of the test was successful.