On 04/21/2010 04:51 PM, George R Goffe wrote:
Howdy,
I'm trying to find out if there are any dependencies within the specific filesystem structures that are specific to 32bit and 64bit.
As far as I know you can mount a filesystem created on an x86_64 system on a x86 machine without any problems but this could just be that I have not been bitten yet and I'd rather avoid that if possible.
Is there a good place to go to find the answer to this question?
There should be no 32- vs. 64-bit dependencies in the implementation of the ext2 or ext3 filesystems. You should be fine.
The most common problem in the past was the use of a 32-bit "int" instead of an "off_t" in the lseek() calls, which limited you to a 2GB file size, but that's an application issue.
The ext2/ext3 filesystem limits are:
Filesystem block size: 1kB 2kB 4kB 8kB
File size limit: 16GB 256GB 2048GB 2048GB Filesystem size limit: 2047GB 8192GB 16384GB 32768GB
Note that the 8kB blocksize was only available on the DEC Alpha, so effectively the maximum filesystem size is 16TB.
There is also a limit of 32K subdirectories in a given directory and there used to be an issue when the number of files grew above 10K inside a directory (big slowdown...fixed with hashed directory entries).
With ext4, the 32K subdirectory limit is removed and it supports filesystems larger than 16TB. Not sure just how big, but BIG! Not sure if the e2fsutils stuff can handle filesystems >16TB yet. ---------------------------------------------------------------------- - Rick Stevens, Systems Engineer, C2 Hosting ricks@nerd.com - - AIM/Skype: therps2 ICQ: 22643734 Yahoo: origrps2 - - - - Jimmie crack corn and I don't care...what kind of lousy attitude - - is THAT to have, huh? -- Dennis Miller - ----------------------------------------------------------------------