lkml.org 
[lkml]   [2002]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [reiserfs-dev] Results of testing Reiserfs on large block devices.
Peter Chubb wrote:

>Hi folks,
> I couldn't get Reiserfs to work on large devices. I've tracked the
>problem down.
>
> When Reiserfs is mounted, it tries to allocate a chunk of memory for
>bitmaps using kmalloc. The largest chunk allocatable by kmalloc is
>128k. This limits the size of a reiserfs to just under 2TB on a
>64-bit platform (16384 bitmaps times 8bytes per pointer) or just under
>4TB on a 32 bit platform (32768 bitmaps times 4bytes per pointer).
>
>This reasoning assumes that the number of bitmaps is given by the
>formula (number_of_blocks + (8 * blocksize - 1))/(8 * blocksize) where
>blocksize is 4096 bytes. Thus
> number_of_blocks = 8 * 4096 * (16384 - 1) - 1 [64 bit]
>
> number_of_blocks = 8 * 4096 * (32768 - 1) - 1 [32 bit]
>
>Hacking mm/slab.c to increase the memory limit allowed larger
>filesystems to be mounted, but I haven't tested these thoroughly yet.
>--
>Dr Peter Chubb peterc@gelato.unsw.edu.au
>You are lost in a maze of BitKeeper repositories, all almost the same.
>
>
>
>
>
Thanks for figuring this out. Oleg will fix it.

--
Hans



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:27    [W:0.038 / U:0.612 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site