[atlas] USB drive more harmful than helpful?

Fwiw, I always power directly from an outlet, never tributary on the USB.
I've yet to have such fails, so my anecdata aligns with the underpower
theory.
On May 20, 2016 15:08, "Phillip Remaker" <remaker at gmail.com> wrote:

So I have a few theories. I have now had 3 different USB sticks fail on me:
Two Sandisk 4GB SDCZ33 and one cheap generic 8GB replacement.

The power draw of the TP-Link system + USB is probably more than the
opportunistic USB ports they get plugged in to. An underpowered probe runs
great MOST of the time, but a flash bit write is probably the highest power
strain and Flash can get really unhappy with power interrupts, based on
this SSD research:
https://www.usenix.org/system/files/conference/fast13/fast13-final80.pdf

I usually use a 500mA or 800mA supply, or tap a nearby router USB port in
that range.
I suspect the system may demand 1200mA or more.

When most flash sticks get errored out enough, they permanently fail into a
read only mode, or become fully unreadable. Read-only mode can be reset on
some models, but it is not recommended by the vendor.  At least one of the
failed SANdisk units I had was stuck in a read-only mode.

Also, probes may be subjected to ungraceful power down situations,
depending on where they are stationed. That can also be a flash drive
killer.

I don't think we are hitting the write limits of the sticks. I suspect the
units are often in underpowered or ungraceful pwoer-down situations, or the
USB flash itself is not responding gracefully to poweroff situations.

I don't suppose RIPE buys enough USB sticks to get to talk to engineers at
SanDISK?

I know the newer Raspberry Pi will report when it is in an underpowered
situation. Can the TP-Link detect and warn when underpowered?

What is the minimum power recommended for TP-Link + USB?  Also, are there
any USB sticks that have lower power needs and are more robust in low power
IoT situations?

Is anyone trying to post-mortem the failed sticks?

On Fri, May 20, 2016 at 10:03 AM, Gert Doering <gert at space.net> wrote:

> Hi,
>
> On Fri, May 20, 2016 at 04:10:47PM +0200, Philip Homburg wrote:
> > We have no clear idea why they fail. It seems that time to failure is
> > highly variable.
>
> Can you correlate tests-until-failure or data-written-until-failure?
>
> One of mine has failed at least two times now, and it could be that
> people just *love* to run tests from 3320...
>
> My gen 1 probe in 5539 has never had *any* issues.
>
> gert
> --
> have you enabled IPv6 on something today...?
>
> SpaceNet AG                        Vorstand: Sebastian v. Bomhard
> Joseph-Dollinger-Bogen 14          Aufsichtsratsvors.: A. Grundner-Culemann
> D-80807 Muenchen                   HRB: 136055 (AG Muenchen)
> Tel: +49 (0)89/32356-444           USt-IdNr.: DE813185279
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.ripe.net/ripe/mail/archives/ripe-atlas/attachments/20160520/f3ea1756/attachment.html>