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* UBI attach, UBIFS mount and blocks writing
@ 2013-11-21 17:33 Fernando Silveira
  2013-11-21 23:29 ` Richard Weinberger
  2013-11-22  1:44 ` Ezequiel Garcia
  0 siblings, 2 replies; 4+ messages in thread
From: Fernando Silveira @ 2013-11-21 17:33 UTC (permalink / raw)
  To: linux-mtd

Hi,

Does a simple UBI attach procedure (e.g. "ubi.mtd=root" at the Linux
cmdline or "ubiattach -m 1") writes something to the flash? What about
a simple read-write mount of a UBIFS partition?

I'm worried about it because my flash has a VERY low limit for
erasing/writing blocks and I'd like to avoid passing read-only
arguments to the "mtdparts" parameter (e.g.
"mtdparts=mynand:8m(boot),-(root)ro") and base only whether I write to
a UBI device or write files to UBIFS partitions in read-write mode.

Regards.

-- 
Fernando Silveira

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: UBI attach, UBIFS mount and blocks writing
  2013-11-21 17:33 UBI attach, UBIFS mount and blocks writing Fernando Silveira
@ 2013-11-21 23:29 ` Richard Weinberger
  2013-11-22  1:44 ` Ezequiel Garcia
  1 sibling, 0 replies; 4+ messages in thread
From: Richard Weinberger @ 2013-11-21 23:29 UTC (permalink / raw)
  To: Fernando Silveira; +Cc: linux-mtd@lists.infradead.org

On Thu, Nov 21, 2013 at 6:33 PM, Fernando Silveira <fsilveira@gmail.com> wrote:
> Hi,
>
> Does a simple UBI attach procedure (e.g. "ubi.mtd=root" at the Linux
> cmdline or "ubiattach -m 1") writes something to the flash? What about
> a simple read-write mount of a UBIFS partition?
>
> I'm worried about it because my flash has a VERY low limit for
> erasing/writing blocks and I'd like to avoid passing read-only
> arguments to the "mtdparts" parameter (e.g.
> "mtdparts=mynand:8m(boot),-(root)ro") and base only whether I write to
> a UBI device or write files to UBIFS partitions in read-write mode.

UBI does wear-leveling, it tests block and replaces them.
UBIFS has for example a journal, which has to be processed at mount time.
The short answer is yes, both can issue writes.

-- 
Thanks,
//richard

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: UBI attach, UBIFS mount and blocks writing
  2013-11-21 17:33 UBI attach, UBIFS mount and blocks writing Fernando Silveira
  2013-11-21 23:29 ` Richard Weinberger
@ 2013-11-22  1:44 ` Ezequiel Garcia
  2013-11-25 15:17   ` Fernando Silveira
  1 sibling, 1 reply; 4+ messages in thread
From: Ezequiel Garcia @ 2013-11-22  1:44 UTC (permalink / raw)
  To: Fernando Silveira; +Cc: linux-mtd

Fernando,

On Thu, Nov 21, 2013 at 03:33:28PM -0200, Fernando Silveira wrote:
> 
> I'm worried about it because my flash has a VERY low limit for
> erasing/writing blocks and I'd like to avoid passing read-only

Which kind of flash is this?

-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: UBI attach, UBIFS mount and blocks writing
  2013-11-22  1:44 ` Ezequiel Garcia
@ 2013-11-25 15:17   ` Fernando Silveira
  0 siblings, 0 replies; 4+ messages in thread
From: Fernando Silveira @ 2013-11-25 15:17 UTC (permalink / raw)
  To: Ezequiel Garcia; +Cc: linux-mtd

Ezequiel,

On Thu, Nov 21, 2013 at 11:44 PM, Ezequiel Garcia
<ezequiel.garcia@free-electrons.com> wrote:
> Which kind of flash is this?

A 2GB NAND flash with < 10k erase count limit. I asked because my
system should be able to reboot hundreds of times (even thousands
sometimes) and avoid rewriting blocks.

-- 
Fernando Silveira

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2013-11-25 15:18 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-11-21 17:33 UBI attach, UBIFS mount and blocks writing Fernando Silveira
2013-11-21 23:29 ` Richard Weinberger
2013-11-22  1:44 ` Ezequiel Garcia
2013-11-25 15:17   ` Fernando Silveira

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