Re: [PATCH/RFC] Linux MTD striping middle layer

Artem B. Bityutskiy
2006-03-21T18:58:22Z

On Tue, 2006-03-21 at 21:11 +0300, Alexander Belyakov wrote:
> Striped mtd device erasesize is an erasesize of subdevice multiplied by
> number of subdevices (in case of equal erasesize subdevices). As
> erasesize is commonly considered as a power-of-2 number it is not good
> idea to use 3, 5, etc devices.
Why? I don't see any thing bad with having 3*128KiB eraseblock size...

> Subdevices are mtd devices which participate in creation of striped mtd
> device (superdevice). vol1, vol2 here are the names of subdevices
> assigned on partitioning stage (for example) by the following part of
> kernel configuration string:
> CONFIG_CMDLINE="..........
> mtdparts=flash1:512k(blob)ro,2m(kernel)ro,16m(root),16m(vol1);flash2:16m(vol2),8m(vol3)
> ........."
IMO, it is better to use MTD device numbers. 0 = mtd0, 1 = mtd1, etc. I
can always glance at /proc/mtd and realize which numbers to use. Names
may contain white spaces, or whatever inappropriate characters one may
conceive, right?

> > 4. I erase eraseblock 0 of mtd7
> In simple case eraseblock 0 on both subdevices 1 and 2 will be erased
I see. Why did you say "In simple case" ?

--
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.