System partition full (newbie)

    • To elaborate on this: Ohm's law is always in place and the 5V rail is the important one. Long USB cables with tiny diameters result in huge voltage drops. The lower the voltage the greater the effect. An external 12V power brick only for the 12V rail of 3.5" disks does change nothing wrt these 'host powered USB storage is a sh*t show' basics with SBC.
    • FabrizioMaurizio wrote:

      So if I use a more powerful power brick for the sbc that should solve the problem right?
      No. And I need to stop supporting SBC since SBC users will never understand that the problem is called undervoltage and related to cable lengths + diameters and not 'amperage' of the power brick in question. You need short USB cables of at least 20AWG rating between your board and the disk. And you need to feed your board with 5.2V.

      If the PSU you have is providing only 5.0V then it will be just 4.9V or even 4.85V on the DC circuitry of the board and if the cable between board and disk is again long and with thin wires the '5V' voltage at the USB-to-SATA bridge and disk has dropped to levels where controllers refuse to work. But to make things worse: only if overall consumption increases then the voltage will drop below the acceptable levels. Ohm's law again.

    • tkaiser wrote:

      You have a 0.2V drop between board's PSU and the adapter and another 0.15V between the adapter's USB side and the SATA power connector. Without any load if I understood correctly.
      that's correct. How do I apply a heavy load to the drive. I tested while muxing a video on the drive and the voltage dropped to 4,90v with the lowest peak at 4,85v at sata connector. Also, since the psu already delivers over 5v and the usb cable is pretty short, does this mean there is nothing I can do to fix this?
    • FabrizioMaurizio wrote:

      How do I apply a heavy load to the drive.
      Random I/O (on most drives that will increase 5V consumption). You need a terminal connection and then switch to the mountpoint in question below /srv/ and then run something like this: [i]iozone -I -e -a -s 100M -r 4k -i 0 -i 1 -i 2[/i].

      Once the random read/write tests run consumption should be the highest. To simulate worst case behavior you can run in another terminal stress -c 4 to stress the CPU somewhat.
    • I did the measurements under load and the minimum was 4,85v. I also measured the other 2 adapters that I own (the one that was on the wd elements external drive (asm1051W) and the usb to dual sata adapter that I bought from ebay (jms561u)). Both these adapters work in different way from the one with the jms578. When I attach the usb to the sbc (only the usb, not the 12v power brick) the jms578 gets 4,97v at the sata connector, the other two adapters get 0v so I'm guessing they get the 5v by converting the 12v they get from the power brick.

      Anyway, these are the results (measurements taken at the sata connector with the drive under load):

      asm1051w - 4,95v
      jms561u - 5,05v-5,10v
      jms578 - 4,85v

      I'm now using the dual sata adapter (jms561u) as it should not be affected by undervolting issues.
      Questions:

      1. Is it possible to fix the jms578 adapter's undervolting issues?
      2. Is it possible that the freezes were caused by transmission since I changed the default values (max downloads: from 5 to 20, max peers per torrent:100, max peers overall:500)?
      3. Should I just ignore this error ERROR Transfer event for disabled endpoint or incorrect stream ring?
    • FabrizioMaurizio wrote:

      1. Is it possible to fix the jms578 adapter's undervolting issues?
      No idea since I'm an electronics noob. But if I remember correctly the power path is not an JMS578 thing but it's a matter of PCB 'quality' (traces too thin and such stuff)

      FabrizioMaurizio wrote:

      2. Is it possible that the freezes were caused by transmission since I changed the default values (max downloads: from 5 to 20, max peers per torrent:100, max peers overall:500)?
      Maybe. The 4.85V you measured are borderline so imagine some CPU intensive stuff is running (increasing consumption at the board) and a lot of random IO activity is happening too (transmission). Another 0.1V drop and some disks already start to throw errors while others are even fine with just 4.4V (not my measurements but Hardkernel folks did some research due to countless 'UAS hassles' with their ODROID XU4 that were simple undervoltage issues in reality).

      FabrizioMaurizio wrote:

      3. Should I just ignore this error ERROR Transfer event for disabled endpoint or incorrect stream ring?
      If it's at booting or when you mount an USB3 disk the first time, then yes. I always got this message, was in contact with a Rockchip engineer two years ago hoping for a fix... but nothing happened and I simply ignored these singular messages.
    • FabrizioMaurizio wrote:

      tkaiser wrote:

      FabrizioMaurizio wrote:

      I have a 32gb emmc, why is my system partition only 7.4gb?
      To allow you to use the last partition for data storage as explained at the download page: sourceforge.net/projects/openm…ngle%20Board%20Computers/An OMV install is pretty fine with less than 4GB so those 8GB we limit the OS partition too are some sort of safety headroom. If you put your dockers on the OS drive on a SD card be prepared that the card might die pretty soon (flashmemory plugin won't help here at all).
      Not sure I understand how this should be setup. Should I format the remaining emmc storage with mkfs.btrfs /dev/mmcblk0p3 and then install the docker containers into that partition or should I use a different sd card completely (I have an empty sd card slot)?
      @tkaiser Can you help me with this one? Thanks!
    • tkaiser wrote:

      Well, all flash memory will eventually wear out. If you put stuff on it resulting in regular writes and especially with a high 'Write Amplification' then it will wear out faster. The flashmemory plugin won't help in these cases and most probably you're not able to replace a worn out eMMC on the PCB.
      The eMMC is not soldered to the board so replacing it should not be a problem. The thing is: it feels kind a waste to use a 32gb emmc just for the operating system. A user in this forum suggested to proceed in this manner to move the docker folder:

      ivanovlk wrote:

      So my solution is :

      1) don't touch the setting in Docker tab
      2) Move /var/lib/docker to external drive (ex. /sharedfolders/data/docker)
      3) sym-lync /sharedfolders/data/docker to /var/lib/docker
    • FabrizioMaurizio wrote:

      it feels kind a waste to use a 32gb emmc just for the operating system
      Well, your eMMC will last longer but since I missed that it's socketed and can be replaced of course you might use it for NAS storage or your containers instead of 'wasting' it. Simply format the last partition with a filesystem of your choice (using btrfs has both advantages and disadvantages and I don't know a bit about OMV's Docker integration)
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