產生檔案

產生 1000 個 500kb 的隨機檔案

for i in {1..100000}; do head -c 500 /dev/urandom > dummy$i; done

產生隨機內容大檔案 (1G)

dd if=<(openssl enc -aes-256-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64)" -nosalt < /dev/zero) of=filename bs=1M count=1000 iflag=fullblock

刪除

刪除大量檔案的目錄

• 方法1(最快)

cd yourdirectory
perl -e 'for(<*>){((stat)[9]<(unlink))}'

• 方法2(次快)

mkdir empty_dir
rsync -a --delete empty_dir/    yourdirectory/

查詢

Inode 用量

find / -xdev -printf '%h\n' | sort | uniq -c | sort -k 1 -n

檔案數量

for t in files links directories; do echo `find . -type ${t:0:1} | wc -l` $t; done 2> /dev/null

查詢最常使用的 20 個指令

history | awk '{print $2;}' | sort | uniq -c | sort -rn | head -20

參考資料

• Efficiently delete large directory containing thousands of files
• Sort history on number of occurences
• Creating a large file of random bytes quickly