Marian +5 informative.

Emi

On 10/16/07, Marian Neagul <[EMAIL PROTECTED]> wrote:
> Salut,
>
>  Poate este un Usb Mass Storage Device mai special. Vezi comentariile
> de mai jos.
>
> On 10/16/07, Teodor Robas <[EMAIL PROTECTED]> wrote:
> >
> > Flash-ul e de 1 GB fara doar si poate (il am de aproape 2 ani).
> > Problema a aparut imediat dupa ce am folosit drive-ul nou de 8 GB, si
> > presupun ca driverul e de vina.
>
> Driverul sau chiar stick-ul
>
> > Din cate stiu eu drive-urile astea au niste algoritmi pentru optimizarea
> > utilizarii celulelor de memorie,
> > astfel incat scrierea unui fisier se face fizic oriunde in memorie unde s-a
> > scris de cele mai putine ori.
> > Asta explica de ce atunci cand aveam o partitie de 1GB+free space fisierele
> > scrise nu erau identice cu
> >  originalul.
>
> Aproape. O mica vizita pe wikipedia iti da urmatoarele informatii:
>
> NAND flash architecture was introduced by Toshiba in 1989. NAND flash
> memories cannot provide execute in place due to their different
> construction principles. These memories are accessed much like block
> devices such as hard disks or memory cards. The pages are typically
> 512 or 2,048 bytes in size. Associated with each page are a few bytes
> (typically 12–16 bytes) that should be used for storage of an error
> detection and correction checksum.
>
> The error-correcting and detecting checksum will typically correct an
> error where one bit per 256 bytes (2,048 bits) is incorrect. When this
> happens, the block is marked bad in a logical block allocation table,
> and its undamaged contents are copied to a new block and the logical
> block allocation table is altered accordingly.
>
> > ambele calculatoare pe care am folosit stick-ul. Deseara o sa incerc si un
> > 2.6.21 pe un alt sistem. Totusi
> > am senzatia ca size-ul actual e scris in flash, si probabil va trebui sa fac
> > cumva sa am access la setarile
> > din flash.
>
> Ai dreptate, daca te uiti in sursele kernelului in
> $KERNSRC/drivers/usb/storage/scsiglue.c o sa gasesti
> urmatoare remarca:
>
> /* A few disks have two indistinguishable version, one of
>                  * which reports the correct capacity and the other does not.
>                  * The sd driver has to guess which is the case. */
>
> :)
>
> Poate te ajuta un pic de hacking in kernel prin analizarea celor doua
> versiuni sa vezi ce capacitate raporteaza.
>
>
>
> --
> Marian Neagul
> Blog: http://blog.segfault.ro
> Phone: +40 729 952 861
>
> _______________________________________________
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>
>


-- 
Emilian Bold
+40 740235562
http://www.emilianbold.ro

Java and NetBeans Platform-loving consulting services from Timisoara, Romania.
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