We write about 100 100GB files into a single 10TB volume with xfs. We are using
allocsize=1g to limit the fragmentation with a great success. We also need to
reserve some space (~200GB) on each filesystem for processing the files and
writing new versions of the files. Once we have only 200GB available we stop
writing to the files. However with allocsize it's not that easy - we see +/-
100GB added or taken depending if there are still writes going and if the file
was reopened ... Is there a way to programmatically disable allocsize
speculative preallocation once we exceed certain threshold and also return the
current speculative preallocation back to the free space (without closing the
file)?
Thx
Peter Vajgel
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