check_flexbuff_usage takes extremely long

[jwagnerhki]

In shared.py check_flexbuff_usage() the step of listing everything found on all disk, i.e., "find /mnt/disk*/ -mindepth 1 -maxdepth 1 -type d | xargs du -b -s --exclude lost+found/" is relatively slow.

For example on Onsala flexbuff of 36 disks it produces about 19 MByte worth of output and takes about 10 minutes.

bonn@kare ~ $ cat try.sh
find /mnt/disk*/ -mindepth 1 -maxdepth 1 -type d | xargs du -b -s --exclude lost+found > /tmp/lst

bonn@kare ~ $ /usr/bin/time ./try.sh
du: cannot read directory '/mnt/disk31/Data/aips': Permission denied
Command exited with non-zero status 123
29.28user 39.10system 10:04.66elapsed 11%CPU (0avgtext+0avgdata 34976maxresident)k
3350472inputs+0outputs (0major+106015minor)pagefaults 0swaps

bonn@kare ~ $ ls -alh /tmp/lst
-rw-rw-r-- 1 bonn bonn 19M Feb 8 12:38 /tmp/lst

With "xargs -P 8" the time drops to 5 minutes. But still excessively long.

Maybe there is a VSI-S query to replace SSH+find+xargs+du...?