Hi
02 Dec 2000, "L.D. Best" <[EMAIL PROTECTED]> wrote:
>> TM> cluster size/allocation unit for FAT32?
>> Ricsi> it could be 512 bytes ... but than MUCH RAM would be wasted
>> Ricsi> ...
>> so M& has chosen to use 4KB for sizes up to 8 GB and 8 KB for
>> larger partitions ... and maybe even larger clusters for huge
>> partitions
LB> Would someone explain to me please how cluster/sector size on a HDD
LB> has any effect on RAM usage?
sector size not ... it's usually 512 bytes.
CLuster size yes ...
you have to store the FAT in RAM ...
with FAT16 there are at most 65535 clusters ....
with FAT32 there are a LOT more ... these take up additional space.
LB> Am I to assume that RAM "stores" instructions and data in active
LB> memory by "sector" rather than by byte?
usually many sectors are grouped together ... these are called clusters.
LB> Thus 1Mb SDRAM can only store x number of sectors even if those
LB> sectors don't add up to anywhere near 1 MegaBYTES of datapoints??
??? I don't see the point
RAM stores bytes, and HDD as well ...
on HDD there can be slack space ... because data is allocated in x bytes
chunks.
LB> I don't see how that could be the case. If it were, then every
LB> memory mapping piece of software ever released to the public would be
LB> a tissue of lies ...
?????
LB> I have an idea that the only reason M$ might have decided to use
LB> unrealistically large sectors would be so there would be less HDD
LB> thrashing when dozerware makes all those diskwrites, even when maximum
LB> cache is allocated to it. If sector size were set to 512, then there
LB> would be better HDD usage but the already flawed files in dozerware
LB> would be fragmented all over the HDD, just inviting one of those
LB> 1,000,000+ unfixed bugs to walk in and take a bite[byte].
??? sector size _IS_ 512 bytes !!
M$ does not use large sectors (who has told you so ??)
The discussion is about FAT32 ...
there can be more clusters, so you can have larger HDDs, and usually
SMALLER clusters ...
But performance degrades ...
LB> Didn't I see somewhere, out of the corner of my eye, that Linux uses
LB> something like FAT32?
?? linux's native filesystem is extfs2 (which is a extremely efficient
filesystem in contrast to (v)fat(32)
but linux has modules that can handle many other file systems
like minix, xenix, (v)fat(32), ntfs,hpfs,....................
LB> It has something going on, since it allows for long files name
LB> [I've yet to find out just how long they can be].
IMHO 255 chars
LB> What sector sizes does Linux allow?
sector size is usually 512 bytes (independant of OS ... hardwaredependant)
but linux does not group sectors together as clusters as DOS does.
So IMHO clustersize=sectorsize=512
LB> l.d.
CU, Ricsi
--
Richard Menedetter <[EMAIL PROTECTED]> [ICQ: 7659421] {RSA-PGP Key avail.}
-=> As for me, all I know is that I know nothing <=-
