@igorp This speed I’ve taken from simple write test dd if=/dev/zero > temp_file with some options and after a sync. Measured time.
The SSD is samsung EVO 860 1 TB formatted to ext4.
However you can’t make more than 625 MB/s on USB 3.0 so there must be sth wrong with your tests.
Why would you use USB3 for drive? It’s slow and prone to troubles. RK3399 has PCI interface and I have connected it there. NvME drive is Samsung 960 PRO 512Gb. Its the fastest I have that is lying around doing nothing.
Whole world is using CrystalDiskMark - Crystal Dew World [en] for measuring drive performances.
iozone is Linux version of it. Use it to get a real picture.
@igorp I use USB 3.0 for drives, because I have specific reasons not to deal with NVMe’s. In CrystalDiskMark I surely get much better results on other SSD drives, without any problem. I’ll try iozone for fun when I switch to Linux from Windows on my desktop, thanks.
Rather measure your USB3 drive with iozone (apt install iozone3) to see its real performances and use DD for fun.
@igorp I am not getting those numbers from iozone, can you explain what are they should be telling me?
Example:
random random bkwd record stride
kB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
64 4 307907 552557 1933893 3406295 2467108 1087638 1562436 1279447 2203800 1066042 1066042 2203800 3203069
Are these kB/s speeds? What is the difference between “kB” and “reclen”?
Type this into the terminal:
man iozone
@igorp I just tried that and I don’t see any explanations what these tons of numbers mean in the manual of this command.
So right after installation new system.After upgrade this file will already have the full value B921B045-1DF0-41C3-AF44-4C6F280D3FAE . Novice may not understand 
p.s. It’s bad that can’t use LABEL in here.
You can use the label actually. Since the partitions is dd, so the partuuid will be the same. You can just custom label when you creating the rootfs.
Hm … With root=LABEL=labelMyRootfs in extlinux.conf I have no boot.
I have the v1.3 and therefore no option to boot directly from the m.2 drive. Moving the files with dd and manually updating the root= works perfect.
The one issue I have is that with each kernel update it revert back to the UUID in the extlinux.conf. However only after a reboot and since the new kernel will only exist on the m.2 card and not on the SD-card stuff breaks horribly.
Is there a way to persist the root change between kernel updates?
In this case make a backup of extlinux.conf file and after apt update/upgrade just use the backup copy and change only the file names, before reboot obviously.
I have a 4b+ and need some help, please.
What to do if using armbian jammy to move to nvme? My system is on eMMC now, but i want to just boot from eMMC and have everything else on nvme?
I don’t have /boot/extlinux/extlinux.conf is /boot/armbianEnv.txt used for this?
There’s this line in it:
rootdev=UUID=cc5076f8-df76-4861-a274-193e1d343175
i looked in /etc/fstab
UUID=cc5076f8-df76-4861-a274-193e1d343175 / ext4 defaults,noatime,commit=600,errors=remount-ro 0 1
i created an empty partition on nvme01 and blkid shows
/dev/nvme0n1p1: UUID=“2c0f8db7-cc21-4069-95e2-09e7756530d7” BLOCK_SIZE=“4096” TYPE=“ext4” PARTUUID=“b22a3064-01”
/dev/mmcblk1p1: LABEL=“armbi_root” UUID=“cc5076f8-df76-4861-a274-193e1d343175” BLOCK_SIZE=“4096” TYPE=“ext4” PARTUUID=“b22a3064-01”
in /dev/disk/by-partuuid is see this (that confuses for me):
lrwxrwxrwx 1 root root 15 Mar 31 18:41 b22a3064-01 -> …/…/nvme0n1p1
Where does this link come from and why is the PARTUUID in blkid the same on /dev/nvme0n1p1 and on /dev/mmcblk1p1 ?