Unable to start new processes

[Rashkae]

On 10-11-04 08:20 PM, Chris MacDonald wrote:
> Ok, sorry for the absolutely horrendous delay, but I've finally got a
> few test machines set up to hopefully solve this.
>
> See my original post for a description of the problem, it still
> applies. I'm seeing this problem on multiple instances of the same
> hardware. The machines are all D510MOs with 1GB of ram and a 4GB USB
> flash drive that is host to Ubuntu, previously 10.04, but now 10.10
> and the errors persist. I captured the error (pasted below) over the
> serial port, but I'd seen it once before and it occurred at a
> different sector. I've restarted the machine and I'm sure it will
> crash again within a day or two. I'm also setting up another machine,
> exact same hardware, I'll see if that fails too.
>
> I'm starting to think this is a systemic hardware fault somewhere, but
> if anyone knows their kernel debug-fu I'd be happy to give something a
> try at my end to hopefully narrow the focus a bit.
>
> [266929.048995] end_request: I/O error, dev sda, sector 776208
> [266929.065740] Buffer I/O error on device sda1, logical block 96770
> [266929.084033] Buffer I/O error on device sda1, logical block 96771
> [266929.102321] Buffer I/O error on device sda1, logical block 96772
> [266929.120692] end_request: I/O error, dev sda, sector 3490352
>    

Well, that there is your error right there.  Theoretically speaking, I 
suppose it's possible that there is some kind of quirk in those 
motherboards that, combined with Linux USB drivers, gets data errors 
when reading/writing to the Memory sticks.


However, given the reproducible nature of your troubles, I think I can 
take the error message at face value,,, when faced with the demands of 
hosting a constant use filesystem, sectors of your flash ram are simply 
getting worn out.  As a rule of thumb, USB flash drives are cheap simple 
devices, unlike hard drives, or even SSD drives, they have neither wear 
level algorithms nor error correction.  It's not all surprising if you 
have a batch of them that, after hundreds, if not thousands of rewrites 
to the same sectors eventually start generating errors.

Keep in mind that, if you do not specify noatime in the filesystem mount 
options, files which are accessed constantly are also getting their 
'access time' constantly updated.  And on a Journaled filesystem, those 
meta-data updates generate even more io for the journaling.  This is not 
the the kind of use Flash Drives are meant to be put too.