"l.a walsh" writes:
=> I notice you can specify extent sizes as a sub-option to the realtime
=> section, but it doesn't seem to be an option for the normal data
=> subsection....a bit of a bummer. Is there a reason why? With a maximum
=> block size of 4k (assuming the man page about linux limitations to page
=> size are still accurate and assuming, I think, Linux uses a 4k pagesize) an
=> d
=> 64K max extent, that's 256k.
The real time partition generally uses much larger datablocks and
uses a different allocation scheme to ensure fast access to blocks.
There's no option to set extent size on a normal XFS filesystem because
XFS tries to allocate your files in as large extents as possible (using
delayed allocation). How effective this is depends on the write patterns,
preallocation and free space/fragmentation on your disk.
Try out 'xfs_bmap' on a file to see how it's actually layed out in extents.
=> Many of my files are > 256k, on one of my larger disks, >15000 files.
=>
=> Is this a temporary limitation or is this sorta a fixed quality of
=> the fs?
IRIX allows FSB sizes between 512 bytes and 64k. Linux XFS only allows
<= PAGE_SIZE FSB sizes due to a limitiation of the linux memory allocator
which would make support for large block sizes inefficient.
-------------------------------------------------------
Daniel Moore dxm@xxxxxxx
R&D Software Engineer Phone: +61-3-98348209
SGI Australian Software Group Fax: +61-3-98132378
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