# Installing on USB/CF/SSD



## mefizto (Mar 18, 2012)

Greetings all,

*I*n the past, several members mentioned that they were installing the FreeBSD OS on the above mentioned media.  It is my understanding that all the media suffer from "write wear."  Since it is my further understanding that the /var and /tmp directories are written to frequently, does this not lead to potential reliability issues?

If someone could comment on my understanding - or misunderstanding, I would appreciate it.

Kindest regards,

M


----------



## fonz (Mar 18, 2012)

mefizto said:
			
		

> It is my understanding that all the media suffer from "write wear."


Indeed. Even traditional hard disks do, but that's probably not what you meant 

I think the most common application of installing FreeBSD (or Linux, or...) onto flash sticks/cards is to create bootable media that are used for installing or for booting encrypted systems. In the former case, filesystems such as /tmp and /var are typically placed in main memory (RAM). In the latter case such filesystems reside on a hard disk and are accessible once disk encryption has been "unlocked" (for lack of a better word). In both cases, not much writing to the flash medium is being done.

Perhaps others can tell you more, but it's a start.

Fonz


----------



## wblock@ (Mar 18, 2012)

mefizto said:
			
		

> in the past, several members mentioned that they were installing the FreeBSD OS on the above mentioned media.  It is my understanding that all the media suffer from "write wear."  Since it is my further understanding that the /var and /tmp directories are written to frequently, does this not lead to potential reliability issues?



Even if you don't take any measures specifically for flash media, people have reported media lasting at least a couple of years.  A couple of easy measures like noatime and maybe logging to a syslog server, and media life becomes even less of a worry.  And a lot of times, flash boot media is used for special appliance-type things like FreeNAS, where it doesn't write to the boot media at all.


----------



## adam2104 (Mar 18, 2012)

Take a look at nanobsd. It*'*s built specifically to handle the challenges of flash memory. With it come a number of tradeoffs but I'm using it quite successfully with an Alix 2D13 platform and a 2GB compact flash card.

Nanobsd:
http://www.freebsd.org/doc/en_US.ISO8859-1/articles/nanobsd/index.html


----------



## mefizto (Mar 18, 2012)

Gentlemen,

*T*hank you for your answers.

Kindest regards,

M


----------



## Beastie (Mar 18, 2012)

wblock@ said:
			
		

> Even if you don't take any measures specifically for flash media, people have reported media lasting at least a couple of years.


Yes, yes. I still have a 256MB pendrive that must be nearly 10 years old now.


----------

