ubuntu@aws:~/slow-mv$ strace -t mv 3GB.copy 3GB
19:00:09 execve("/bin/mv", ["mv", "3GB.copy", "3GB"], 0x7ffd0e7dddf8 /* 21 vars */) = 0
19:00:09 brk(NULL)                      = 0x55cd7d1ce000
19:00:09 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
19:00:09 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
...
19:00:09 getgid()                       = 1000
19:00:09 access("3GB", W_OK)            = 0
19:00:09 rename("3GB.copy", "3GB")      = 0
19:00:18 lseek(0, 0, SEEK_CUR)          = -1 ESPIPE (Illegal seek)
19:00:18 close(0)                       = 0
19:00:18 close(1)                       = 0
19:00:18 close(2)                       = 0
19:00:18 exit_group(0)                  = ?
19:00:18 +++ exited with 0 +++
ubuntu@aws:~/slow-mv$