[arm-allstar] SD Cards

[Doug Crompton]

Wear leveling is a process of the cards memory management system and not the Linux OS at least not with the format we are using so the entire card would be leveled not just the used portion. This is also true of SSD drives. The history we have, almost two years of 24/7 running systems indicates that the concern about writes to the SD card in our application is not a concern. In my personal experience and that reported to me I have yet to see the demise of a quality SD card in our application. I would also add that unless your system is in a remote location, that you can not easily get to, a backup SD card stored near the system would get you back on the air in minutes should it be needed.

Another thing that I recommend if you are going to do big writes like turning on archiving with audio or any application where you are making repetitive writes to the SD card is to use a usb memory stick. The stick could use its native fat32 format or be formatted ext4 or any Linux format. In that way you could have 64GB or more of expendable memory.  
73 Doug
WA3DSP
http://www.crompton.com/hamradio


> Date: Thu, 3 Dec 2015 10:28:51 -0700
> From: willem at prinmath.com
> To: arm-allstar at hamvoip.org
> Subject: Re: [arm-allstar] SD Cards
> 
> On Thu, 3 Dec 2015, Doug Crompton wrote:
> 
> > Also as I mentioned on the web page unless you have a compelling reason 
> > it is NOT a good idea to expand the filesystem on these cards after 
> > installing the image. Doing so makes total image backup a time consuming 
> > process especially on 16GB and larger cards and does nothing to improve 
> > performance or longevity.
> 
> Doug, while I agree regarding performance and backup, I don't know if a 
> agree about longevity.  At least in principle, wear leveling should give 
> you a longer life on a larger file system for the same volume of data 
> written, should it not?  What I will grant you is that the SD cards in 
> rPi's that I have lost usually was not due to wear, but due to power 
> transient and those kinds of catastrophic events.  However, all else being 
> equal I think there is a case to be made that increasing the file system 
> size.  Am I missing something?
> 
> 73 -Willem
> 
> ================================================================
> Dr. Willem A. Schreuder,  President,  Principia Mathematica
> Address:  445 Union Blvd, Suite 230,  Lakewood, CO  80228, USA
> Tel: (303) 716-3573   Fax: (303) 716-3575
> WWW: www.prinmath.com   Email: Willem.Schreuder at prinmath.com
> _______________________________________________
> 
> arm-allstar mailing list
> arm-allstar at hamvoip.org
> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> 
> Visit the BBB and RPi2 web page - http://hamvoip.org
> 
 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.hamvoip.org/pipermail/arm-allstar/attachments/20151203/9cd44c32/attachment.html>