Messages in this thread | | | Date | Wed, 31 Jul 2002 23:04:12 +0300 | From | Matti Aarnio <> | Subject | Re: BIG files & file systems |
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On Wed, Jul 31, 2002 at 08:26:38PM +0100, Christoph Hellwig wrote: > On Wed, Jul 31, 2002 at 01:16:20PM -0600, Peter J. Braam wrote: > > Hi, > > > > I've just been told that some "limitations" of the following kind will > > remain: > > > > page index = unsigned long > > ino_t = unsigned long > > > > Lustre has definitely been asked to support much larger files than > > 16TB. Also file systems with a trillion files have been requested by > > one of our supporters (you don't want to know who, besides I've no > > idea how many bits go in a trillion, but it's more than 32). > > What about using 64bit machines? ..
It depends on many things: - Block layer (unsigned long) - Page indexes (unsigned long) - Filesystem format dependent limits - EXT2/EXT3: u32_t FILESYSTEM block index, presuming the EXT2/EXT3 is supported only up to 4 kB block sizes, that gives you a very hard limit.. of 16 terabytes (16 * "10^12") - ReiserFS: u32_t block indexes presently, u64_t in future; block size ranges ? Max size is limited by the maximum supported file size, likely 2^63, which is roughly 8 * "10^18", or circa 500 000 times larger than EXT2/EXT3 format maximum. - ClusterFS: (Braam et.al.): 64 bit block indexes ? System file size limitation, same as with ReiserFS.
(Just to illustriate a few..)
/Matti Aarnio - 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/
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