32Gb class 10 mSD - Re: SD card programing -

Robert Moskowitz rgm at htt-consult.com
Thu Apr 30 14:41:01 UTC 2015


Just got this pointer in an email:

http://view.newsletter.rakuten.com/?j=fe8815707c6d017473&m=fe8d12717c62077d7c&ls=fe5f137175660d7e7112&l=ff2416797d6c&s=fe5a157373660c7b7210&jb=ff3615717167&ju=fe6616747665027f7016&r=0

I have bought a number of items from Rakuten and a happy with them.



On 04/30/2015 10:08 AM, Robert Moskowitz wrote:
>
>
> On 04/30/2015 09:08 AM, Dave Ihnat wrote:
>> On Wed, Apr 29, 2015 at 10:46:38PM -0400, Robert Moskowitz wrote:
>>> I have a Microcomputer center a couple miles away, and they have mSD
>>> cards by the dozens at the checkout counters.  Each comes with the
>>> SD adapter.  I think I just spent $9 each for a few more 16Gb cards
>>> for my testing.
>> I've been using the EMTec cards carried by MicroCenter.  I don't trust
>> no-name or store-branded cards.  There are just too many fraudulent 
>> cards
>> out there.  I've considered using MicroCenter's, just because I can 
>> go back
>> to the store if there are problems, but the difference in price 
>> hasn't been
>> worth it.
>
> That is why I blow away their partitions and do my own, even if I want 
> a DOS partition.  I once, REALLY, got a USB stick from ecost.com that 
> had this strange hidden partition on it with this interesting code 
> that had an IP address imbedded in it.
>
>> Also, another thing you should consider is that there are speed 
>> classes of SD
>> cards from 3-10.  You want Class 10--10MB/s.  You'll often see Class 
>> 2,4,
>> and 6 cards at great prices--there's a reason.
>
> I am looking at the card I got last week and it says C10.
>
>> I hate to recommend a Microsoft-based solution--try running it under
>> wine or something, if it offends the sensibilities--but look for, get
>> and run a little ditty called h2testw.exe (best site would be the 
>> source,
>> http://www.heise.de/download/h2testw.html--it's a German author and 
>> site,
>> but you can figure it out.)  There are Linux alternatives--the one that
>> comes to mind is F3:
>>
>>    http://oss.digirati.com.br/f3/
>>
>> Others, and some discussion of the problem:
>>
>> https://www.raymond.cc/blog/test-and-detect-fake-or-counterfeit-usb-flash-drives-bought-from-ebay-with-h2testw/
>>
>> Some think that a RPi OS running off a SD card should be "tuned"; others
>> dismiss this, as the card specs give a large number of R/W ops before 
>> MTBF.
>> Nevertheless, especially if you're going to run 24x7, some things just
>> make sense:
>>
>>    o Turn on noatime in fstab
>>    o Use tmpfs in fstab
>>    o Use a bigger card--not for storage space, but wear leveling.
>
> The latest uboot for F22 (and kernel) can just have uboot on the SD 
> card and then switch to your sata for everything else.  That is the 
> nice thing about Cubies (and Wands and a few others).  Real sata 
> port.  Hans is working on USB drive support out of uboot, but I have 
> not heard if he has that working yet.  There are a few things that 
> won't made F22 and we will have to wait for F23 for them.
>
>> As far as size--Raspbian comes as a 2GB image, which you expand to 
>> use the
>> capacity of the card.  If you'r not going to do a lot of local data
>> storage, 8GB will work well (and be a lot cheaper).  16GB is a nice
>> compromise on cost/capacity (and wear leveling, if you believe in 
>> that as
>> an issue).  32GB is pricy, and if you're thinking about that much 
>> storage
>> maybe you want to hang a USB HDD or even SDD off the box; after all, 
>> we now
>> have four USB ports with the Pi 2.
>
> Better to go with a smallish SD and put on a USB drive for your root 
> and such.
>



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