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root@localhost:~ $ df /dev/sdb1
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sdb1            1922858352  23247088 1801935664   2% /mnt/external/sdb1

used+available = 1825182752

Size - 1825182752 = 97675600

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You've obviously meant Size - 1825182752. – GrzegorzOledzki Feb 24 '11 at 16:07
Thank you... ugh. – andyortlieb Feb 24 '11 at 16:10
up vote 5 down vote accepted

97675600 / 1825182752 = 5% this is the default reserved space for root user.

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That's an interesting point, however I would expect df to tabulate the physical usage, and not to take into account such a reservation. Is there a switch or a different utility that shows the physical available space? – andyortlieb Feb 24 '11 at 16:08

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