Hi Peter,
Sorry to bother you again, I was looking at the filesystem code for ufs.h and I found that there are some metadata which is highly dependent on whether the OS support 32bit or 64bit.
Snippet of ufs super block.
__fs64 fs_size; /* number of blocks in fs */
__fs64 fs_dsize; /* number of data blocks in fs */
__fs64 fs_csaddr; /* blk addr of cyl grp summary area */
__fs64 fs_pendingblocks;/* blocks in process of being freed */
__fs64 fs_dsize; /* number of data blocks in fs */
__fs64 fs_csaddr; /* blk addr of cyl grp summary area */
__fs64 fs_pendingblocks;/* blocks in process of being freed */
Number of data blocks supported on 64-bit(UFS) filesytem will be more then that of the 32-bit (UFS) filesystem. So if we want 32-bit UFS filesystem(on 32 bit OS) to support data block as many as 64-bit UFS file sytem then we have to modify UFS 32 bit filesystem.
So my question is, whether the 64-bit filesystem is supported on 32-bit OS?
I think it can be supported but with some changes in metadata structure which will definitely add some performance hit...
Please confirm if this understanding is correct or not!!
-Manish R
On Sun, Aug 16, 2009 at 8:17 PM, manish <rangankarmanish@xxxxxxxxx> wrote:
Thanks Peter... I had this question because one of the project I am working on had a two different flavour of UFS.. one is UFS and other one is UFS64 bit, ported on proprietary OS.-ManishOn Sun, Aug 16, 2009 at 5:26 PM, Peter Teoh <htmldeveloper@xxxxxxxxx> wrote:
thanks for the confirmation.....the only thing that matters is
performance. as the data structure for the VFS layer is independent
(generally, i think) of 64 or 32bit kernel, so it should be indep of
64/32bit kernel, but because 64bit have a larger data I/O rate, so
performance should be higher....at the expense of more memory
consumed......
--
On Sun, Aug 16, 2009 at 6:09 PM, SandeepKsinha<sandeepksinha@xxxxxxxxx> wrote:
> Hi Manish,
>
> On Sat, Aug 15, 2009 at 9:20 PM, Peter Teoh <htmldeveloper@xxxxxxxxx> wrote:
>>
>> i don't think there is such a thing as 32/64 bit filesystem.
>> Filesystem type does not need to be linked to the OS's 32/64 bit
>> architecture. Ie, ext2 or ext3, is the same when mounted in either
>> filesystem. but the content within filesystem does matter, eg, if it
>> is 32/64bit executable etc.
>
> This is true !!!!
>
>
> Regards,
> Sandeep.
>
>
>
>
>
>
> “To learn is to change. Education is a process that changes the learner.”
>
>
>
>
>>
>> On Sat, Aug 15, 2009 at 1:37 AM, manish<rangankarmanish@xxxxxxxxx> wrote:
>> > Hi All,
>> >
>> > I have basic query!!
>> >
>> > I can have 32 and 64 bit filesystem on 64-bit kernel. Is it possible to
>> > have 64-bit filesystem on 32 bit kernel? Does linux support it?
>> >
>> > -Manish R
>>
>>
>>
>> --
>> Regards,
>> Peter Teoh
>>
>> --
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>
>
Regards,
Peter Teoh
