Rsync備份一個源目錄，並再次檢查多個目錄

Question

我想將「sdir」目錄根據當天的情況複製（rsync）到tdir目錄。我想要一個完整的副本到mon目錄，只改變了什麼，只改變了什麼，等等，但我沒有得到我需要的結果。 參考實際的命令我跑：

[jesse@localhost test]$ tree 
. 
├── sdir 
│ ├── file1 
│ ├── file2 
│ ├── file3 
│ ├── file4 
│ └── file5 
└── tdir 
    ├── fri 
    ├── mon 
    │ ├── file1 
    │ └── file2 
    ├── thu 
    ├── tue 
    │ └── file3 
    └── wed 
     ├── file3 
     ├── file4 
     └── file5 

7 directories, 11 files 
[jesse@localhost test]$ touch sdir/file6 
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir//thu/ --backup-dir=/home/jesse/test/tdir/fri/ 
sending incremental file list 
./ 
file3 
file4 
file5 
file6 

sent 294 bytes received 31 bytes 650.00 bytes/sec 
total size is 0 speedup is 0.00 (DRY RUN) 
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir//thu/ --backup-dir=/home/jesse/test/tdir/thu/ 
sending incremental file list 
./ 
file3 
file4 
file5 
file6 

sent 294 bytes received 31 bytes 650.00 bytes/sec 
total size is 0 speedup is 0.00 (DRY RUN) 
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ --backup-dir=/home/jesse/test/tdir/thu/ 
sending incremental file list 
./ 
file6 

sent 208 bytes received 22 bytes 460.00 bytes/sec 
total size is 0 speedup is 0.00 (DRY RUN) 
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir/thu/ --backup-dir=/home/jesse/test/tdir/thu/ 
sending incremental file list 
./ 
file3 
file4 
file5 
file6 

sent 294 bytes received 31 bytes 650.00 bytes/sec 
total size is 0 speedup is 0.00 (DRY RUN) 
[jesse@localhost test]$ rsync -av sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir/thu/ --backup-dir=/home/jesse/test/tdir/thu/ 
sending incremental file list 
./ 
file3 
file4 
file5 
file6 

sent 438 bytes received 95 bytes 1,066.00 bytes/sec 
total size is 0 speedup is 0.00 
[jesse@localhost test]$ tree 
. 
├── sdir 
│ ├── file1 
│ ├── file2 
│ ├── file3 
│ ├── file4 
│ ├── file5 
│ └── file6 
└── tdir 
    ├── fri 
    ├── mon 
    │ ├── file1 
    │ └── file2 
    ├── thu 
    │ ├── file3 
    │ ├── file4 
    │ ├── file5 
    │ └── file6 
    ├── tue 
    │ └── file3 
    └── wed 
     ├── file3 
     ├── file4 
     └── file5 

7 directories, 16 files 
[jesse@localhost test]$ 

Answer 1

我注意到，rsync手冊頁明確指出「開始在2.6.4版本中，多--link-dest目錄可以提供」，並有一個類似的說明爲--compare-dest但不是--backup-dir（這是有道理的）。如果你想限制你的備份「只有不在其他目錄之一中的東西」，--*-dest選項是要走的路。

這裏是我的測試和結果：

$ mkdir src mon tue wed 
$ for n in {1..3}; do date > src/file$n; sleep 1; done 
$ rsync -avi src/ mon/ 
building file list ... done 
.d..t.... ./ 
>f+++++++ file1 
>f+++++++ file2 
>f+++++++ file3 

sent 346 bytes received 92 bytes 876.00 bytes/sec 
total size is 87 speedup is 0.20 
$ for n in {4..5}; do date > src/file$n; sleep 1; done 
$ rsync -avi --compare-dest=$PWD/mon/ src/ tue/ 
building file list ... done 
.d..t.... ./ 
>f+++++++ file4 
>f+++++++ file5 

sent 295 bytes received 70 bytes 730.00 bytes/sec 
total size is 145 speedup is 0.40 
$ for n in {6..7}; do date > src/file$n; sleep 1; done 
$ rsync -avi --compare-dest=$PWD/mon/ --compare-dest=$PWD/tue/ src/ wed/ 
building file list ... done 
.d..t.... ./ 
>f+++++++ file6 
>f+++++++ file7 

sent 319 bytes received 70 bytes 778.00 bytes/sec 
total size is 203 speedup is 0.52 
$ 

這裏的顯着區別是，比較目錄的每個需要自己選擇。記號是不是：

rsync --compare-dest one/ two/ src/ dest/ 

而是：

rsync --compare-dest=one/ --compare-dest=two/ src/ dest/ 

爲了把這個成被每天運行的代碼，你可以嘗試類似如下（未經測試腳本）：

#!/usr/bin/env bash 

# Store our rsync arguments in an array, for easier handling. 
rsync_args=(-a) 

# If we're running interactively, show us rsync verbose output. 
if [ -t 0 ]; then 
    rsync_args+=(-vi) 
fi 

# Step through weekdays, adding days to our argument list, stopping at "today" 
read today < <(date '+%a') 
for day in Mon Tue Wed Thu Fri; do 
    [ "$day" = "$today" ] && break 
    rsync_args+=(--compare-dest=$PWD/${day,,}) 
done 

# And finally, copy everything. 
rsync "${rsync_args[@]}" src/ "${day,,}"/ 

請注意，參數擴展（${s,,}和${s^^}）中的bash案例控件是bash版本4的特性。