[arm-allstar] Some thoughts on SD cards and updates

[Doug Crompton]

It is important to do Hamvoip updates in a timely manner and not wait for
years to do it when the update involves a great deal of code to be
downloaded and installed. 99.99% of updates perform flawlessly. When doing
an update you want to make sure you have no interruptions of power or
Internet. If either are unreliable you should wait until they are not. You
should also never stop an update midstream, wait until it is done.

In general SD cards are very reliable as long as you buy and use quality
cards. We recommend using SanDisk cards, generally 16G although in the
future only 32G or larger may be available. Current recommended product -

https://www.amazon.com/Sandisk-Ultra-Micro-UHS-I-Adapter/dp/B073K14CVB/ref=sr_1_2

Currently $5.99 or less in quantity.

Using Hamvoip code on the Pi very little if anything is actually written to
the card in normal operation. Logs and frequently written data are all
stored in RAM on the Pi. If you do things beyond the normal code that write
to the card a large amount of time then there will be a life but that life
is considerably long. I have cards that go back many years of life. That
being said cards are cheap and swapping out old ones is probably a good
idea at some point. Just remember, don't be cheap, throw out the old card
or use it for something that is non critical!

Several things can cause a card to be corrupted. The worse thing you can do
is turn off the power without properly shutting down. This generally does
not cause a problem but that one time could be disastrous. Putting your Pi
on a UPS is a good idea. Also battery backed up auto shutdown boards are
available to take care of this.

Another thing that can cause havoc is poor power to the Pi. Buy a good
power source not the cheapest one you can find. Poor power is the first
thing you should consider when you have an erratic Pi.

To put this in perspective there are many thousands of Pi nodes out there
and a very very small percentage have or will have problems. The SW and HW
is very reliable. When you hear one person having problems here remember it
is a small fraction of a percent of the total users.


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*