# Linux singer 6.6.37-0-lts x86_64
# /dev/shm is tmpfs
# as user, nsm here:
#   touch /dev/shm/mempool.dat.new
# as root:
#   cd /home/nsm/.bitcoin
#   mount -o rw,bind /dev/shm/mempool.dat.new mempool.dat.new
# everything else here that follows
# is run as an unprivileged user
+ date -u
Sat Feb 22 08:35:00 UTC 2025
+ mountpoint /home/nsm/.bitcoin/mempool.dat.new
/home/nsm/.bitcoin/mempool.dat.new is a mountpoint
+ grm.sh
+ safecat.sh /dev/shm/mymempool.txt
+ time sh -c 'bitcoin-cli savemempool 2>/dev/null; true'
real	0m 2.03s
user	0m 0.00s
sys	0m 0.00s
+ f=/dev/shm/mempool.dat.new
+ t=/dev/shm/mempool.dat.tmp
+ cp /dev/shm/mempool.dat.new /dev/shm/mempool.dat.tmp
+ : UNIX fixes this, file descriptor stays when used
+ : even after file was successfully unlinked
+ mv /dev/shm/mempool.dat.tmp /dev/shm/mempool.copy
+ cd /dev/shm
+ ls -ilh mempool.copy mempool.dat.new
534754 -rw-r--r-- 1 nsm nsm 127M Feb 22 08:35 mempool.copy
183442 -rw-r--r-- 1 nsm nsm 127M Feb 22 08:35 mempool.dat.new
+ cd /home/nsm/web/ln
+ ls -l mymempool-log.txt mymempool.dat mymempool.txt
lrwxrwxrwx 1 nsm nsm 22 Feb 21 13:10 mymempool-log.txt -> /dev/shm/mymempool.log
lrwxrwxrwx 1 nsm nsm 21 Dec 10 12:10 mymempool.dat -> /dev/shm/mempool.copy
lrwxrwxrwx 1 nsm nsm 22 Feb 18 11:10 mymempool.txt -> /dev/shm/mymempool.txt
+ bitcoin-cli getmempoolinfo
{
  "loaded": true,
  "size": 78804,
  "bytes": 61477477,
  "usage": 371170480,
  "total_fee": 0.93832048,
  "maxmempool": 500000000,
  "mempoolminfee": 0.00001000,
  "minrelaytxfee": 0.00001000,
  "incrementalrelayfee": 0.00001000,
  "unbroadcastcount": 0,
  "fullrbf": true
}
+ date -u
Sat Feb 22 08:35:03 UTC 2025