[hfs-user] (no subject)

Biswaroop Banerjee Biswaroop Banerjee" <biswaroopb@integramicro.com
Fri, 15 Mar 2002 16:11:08 +0530


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hi everybody,

In the MDB structure for a HFS volume has a member.

drxtTClpSiz, this member stores the clump size for the
extents overflow file.
In the linux code it is calculated as follows

vol.mdb.drXTClpSiz =3D vol.mdb.drNmAlBlks / 128 * vol.mdb.drAlBlkSiz;

where

vol.mdb.drXTClpSiz =3D Stores the Clump size for the extents overflow =
file.
vol.mdb.drNmAlBlks =3D Stores the number of Allocation blocks for the =
HFS volume =20
vol.mdb.drAlBlkSiz =3D Stores the number of bytes per Allocation Block.




My doubt is why this formula is used to calculate the Extent file's =
clump size.

Can i make it equal to just clump size calculated for the Volume??


/*Info*/

1. A allocation block is integral times of a Logical Block , which for =
HFS is 512 bytes.

2. Clump size is integral times of  Allocation Block size and it is the =
amount of space allocated  when a file is created to store the file =
contents.


Waiting for your explanations!

Bye
Biswaroop

 =20

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<DIV><FONT face=3DArial size=3D2>hi everybody,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>In the MDB structure for a HFS volume =
has a=20
member.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>drxtTClpSiz, this member stores the =
clump size for=20
the</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>extents overflow file.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>In the linux code it is calculated as=20
follows</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>vol.mdb.drXTClpSiz =3D =
vol.mdb.drNmAlBlks / 128 *=20
vol.mdb.drAlBlkSiz;</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>where</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>vol.mdb.drXTClpSiz =3D Stores the Clump =
size for the=20
extents overflow file.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>vol.mdb.drNmAlBlks =3D Stores the =
number of=20
Allocation blocks for the HFS volume&nbsp; </FONT></DIV>
<DIV><FONT face=3DArial size=3D2>vol.mdb.drAlBlkSiz =3D Stores the =
number of bytes per=20
Allocation Block.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>My doubt is why this formula is used to =
calculate=20
the Extent file's clump size.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Can i make it equal to just clump size =
calculated=20
for the Volume??</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>/*Info*/</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>1. A allocation block is integral times =
of a=20
Logical Block , which for HFS is 512 bytes.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>2. Clump size is integral times =
of&nbsp; Allocation=20
Block size and it is the amount of space&nbsp;allocated &nbsp;when a =
file is=20
created to store the file contents.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Waiting for your =
explanations!</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Bye</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Biswaroop</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>&nbsp; </FONT></DIV></BODY></HTML>

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