DISCLAIMER:  I am not asking for help;  I'm sharing my experiences.

Encountered an interesting situation on one XO-1 with os11 (12.1.0): On completely random occasions, the boot-up sequence stops because of i/o errors on device mmcblk0. Without making any changes whatsoever, the very next boot-up runs fine.

[EDIT:  I've now put os12 on that system.  Problem has not re-occurred.]


[I've discussed with Kevin the question of "when during boot-up is it a good time to mount an SD card?" In my case, I need Sugar to find resources located on that card -- so I need that card to be already accessible when Sugar is starting up.]

For three years now, as part of my XO customization I've had an initialization script in /etc/rc.d/init.d/ that issues an explicit 'mount' of my "permanent" SD card -- and that script has always worked well. [For historical reasons, my mount point is to a subdirectory in /media.] Now I'm starting to see these random errors after that script is installed. [I've reinstalled os11 on that system several times from scratch -- since the problem keeps coming back it is NOT due to an operator mistake while installing.]

The closest I have to a clue is that /media appears to be empty. I'm speculating that after my initialization script tests for the existence of my mount point subdirectory (and creates that subdirectory if need be), something is wiping /media. And that the 'mount' command (or a subsequent bash 'test -f' command) is getting errors because the inode it looks for is not present.

[I don't think the errors occur before my initialization script gets run. If the system were accessing the SD card, it would do so whether my script was there or not. Yet the errors only show up after my script has been installed - so its presence must have an influence.]


So far, I've put os11 on only a couple of XO-1s. This is the only system on which I'm having this problem. I'm guessing that there is some sort of a race condition - such that ordinarily my mount point subdirectory gets left alone after my initialization script has created it. But on random occasions with this particular system, something seems to be happening WHILE my initialization script is running -- and that interference results in my customized boot-up sequence now seeing i/o errors with device mmcblk0.


mikus


p.s. [If this problem persists, I'll experiment with allocating my mount point elsewhere. But that means changing a number of scripts -- I don't want to make such modifications unless absolutely m=necessary.]


pps. This is one of the XO-1 systems on which I can get randomly occurring "Bad read of .img file" messages while using 'OFW to copy-nand' a build image from an USB stick. The same USB stick works well with "non-sensitive" XOs.

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