Please reference paragraph 5.10 on p37 of BBB SRM.
Does memory device contamination occur due to open files in the Linux OS, or due to improperly sequenced power to a memory devices inadvertently writing to a memory device?
Thanks,
Bruce
Most common is powering off the board without mounting the drives under Linux.
Gerald
Assume you mean: … without /un/mounting the drives under Linux.
Is there any data (or guesses) on how many times I can power down without unmounting before the eMMC is going to the dodo?
thx,
Michiel
Well... This "guess" needs more data.. Is the partition ro? What file
system? etc etc...
So without any of the important data, I'll give you the best answer:
"zero"... Yeap zero chance of a 100% data match of data on the drive
right before you yank power...
Regards,
Sure, let’s say just your latest greatest debian kernel 3.14 running headless doing nothing only being great?
Any experiences with broken eMMCs? How important is using a backup battery in a daily unclean power down situation. What’s your feeling: days, weeks, months, years, decades?
Hmmm, I guess I’ve some work to do in shutting down some bbb’s properly otherwise I can answer my own question. Thinking aloud a battery and bringing the power button external.
thx,
Michiel
Sure, let's say just your latest greatest debian kernel 3.14 running
headless doing nothing only being great?
Still missing the point..
So in that case, you have ext4, and / mounted rw with noatime..
Let's say it's idle:
It'll survive a few power yanks and fsck.ext4 will fix it up most of the time..
I'd say about a week before you'll have to reflash the eMMC to due
file system corruption...
Any experiences with broken eMMCs? How important is using a backup battery
in a daily unclean power down situation. What's your feeling: days, weeks,
months, years, decades?
Really anything > then a week of unclean power down's, start looking
at "read only root"* and other file systems.
* We have a beagleboard-xm running on the roof of this building as a
webcam taking pictures all day, it's been running (off/on) for over 3
years on the same microSD card running Debian Squeeze, on a read only
rootfs.. It's powered by a solar array, so power is variable all day
long..
https://wiki.debian.org/ReadonlyRoot
Hmmm, I guess I've some work to do in shutting down some bbb's properly
otherwise I can answer my own question. Thinking aloud a battery and
bringing the power button external.
Regards,
Interesting, I will (also) look into ro root solution, thanks!
Can I conclude that:
- journaling ext4 is not as robust as me thought it was only capable of restoring limited damage
- Yanking power is corrupting the fs, not the eMMC.
- and therefor we can repair the fs by reflash the eMMC without any hardware damage done.
thx,
Michiel
Robert
Sure, let’s say just your latest greatest debian kernel 3.14 running
headless doing nothing only being great?Still missing the point…
So in that case, you have ext4, and / mounted rw with noatime…
Let’s say it’s idle:
It’ll survive a few power yanks and fsck.ext4 will fix it up most of the time…
I’d say about a week before you’ll have to reflash the eMMC to due
file system corruption…Any experiences with broken eMMCs? How important is using a backup battery
in a daily unclean power down situation. What’s your feeling: days, weeks,
months, years, decades?Really anything > then a week of unclean power down’s, start looking
at “read only root”* and other file systems.
- We have a beagleboard-xm running on the roof of this building as a
webcam taking pictures all day, it’s been running (off/on) for over 3
years on the same microSD card running Debian Squeeze, on a read only
rootfs… It’s powered by a solar array, so power is variable all day
long…
Is there such a debian image available for beaglebone black ?
Hi RobertIs there an image available for the debian ReadonlyRoot for Beaglebone Black?
https://wiki.debian.org/ReadonlyRoot
Thanks
Vic