Some experiments with boot up. I was going to use the Pi to copy all the files from a full 2 TB SSD to an empty 4 TB magnetic disk. When both disks were in before switching on the Pi, the magnetic disk would open in file manager then do something funny. dmesg says the disk was restarted in read only. I presume it is low voltage due to some peak power usage.
If both disks are unplugged at boot then plugged in after the OS completes the boot, both disks would appear in file manager and let me copy. After a while, the magnetic disk would switch to read only. Given it is a constant power draw at that stage, I do not know why the problem would occur. Perhaps the SSD ramps up the erase cycles after a while and uses more power.
The copy should be IO limited by the magnetic disk at less than USB 3 speed. On the Pi 5, the copy time is estimated at 36 hours. My notebook says 18 hours. That might be the shared USB speed although on my notebook, both disks are plugged into the same USB 3 chip.
If the problem is some random peak power draw in the SSD, I do not understand why there is a difference between three RTL9210 based enclosures. I have a USB power meter I will use to test the devices. and, as I have not used the power meter before, I do not know how accurate the meter will be for finding instantaneous peaks.
The power supply is the official Pi 5 block. The 2 TB SSD would draw more power than the 0.5 TB SSD. The 2 TB SSD works perfectly in at least one out of the three RTL9210 enclosures. In the first one, there is no activity and no indication in dmesg that anything is plugged in but the same thing works in other computers.
If both disks are unplugged at boot then plugged in after the OS completes the boot, both disks would appear in file manager and let me copy. After a while, the magnetic disk would switch to read only. Given it is a constant power draw at that stage, I do not know why the problem would occur. Perhaps the SSD ramps up the erase cycles after a while and uses more power.
The copy should be IO limited by the magnetic disk at less than USB 3 speed. On the Pi 5, the copy time is estimated at 36 hours. My notebook says 18 hours. That might be the shared USB speed although on my notebook, both disks are plugged into the same USB 3 chip.
If the problem is some random peak power draw in the SSD, I do not understand why there is a difference between three RTL9210 based enclosures. I have a USB power meter I will use to test the devices. and, as I have not used the power meter before, I do not know how accurate the meter will be for finding instantaneous peaks.
The power supply is the official Pi 5 block. The 2 TB SSD would draw more power than the 0.5 TB SSD. The 2 TB SSD works perfectly in at least one out of the three RTL9210 enclosures. In the first one, there is no activity and no indication in dmesg that anything is plugged in but the same thing works in other computers.
Statistics: Posted by peterlite — Fri May 31, 2024 1:01 am