Re: 64-bit block sizes on 32-bit systems

Dave Kleikamp
2001-03-28T14:57:12Z

My turn to chime in.

JFS was designed around a 4K meta-data page size. It would require some
major re-design to use larger block sizes. On the other hand, JFS could
take advantage of 64-bit block addresses immediately. JFS internally
store the block address in 40 bits. (Sorry, file size & volume size are
both limited to 4 peta-bytes on JFS.)

At the rate that storage hardware and requirements are increasing,
increasing the block size is a short-term solution that is only going to
delay the inevitable requirement for 64-bit block addressability. There
is a practical limit to a usable block-size. Someone threw out 64K,
which seems reasonable to me.
--
David Kleikamp
IBM Linux Technology Center