zfs鏡像功能測試

4月底新的ubuntu22.04系統發佈的時候,好奇心讓我選擇了zfs文件系統,早有耳聞zfs,後來自己安裝更新linux內核deb包的時候,發現無法引導系統,彼時有點慌,因爲zfs文件系統無法識別,沒辦法只能上網查詢資料,原來因爲開源協議的問題,內核並沒有像ext4那樣包含zfs的相應處理模塊,有糾紛的話,Oracle的律師會發律師函。

題外話不多說,既然ubuntu官方提供了對應的文件系統選項,加上bsd等也選用zfs文件系統,肯定有其獨到之處,對於窮苦大衆來說,zfs的snapshot即快照功能絕對夠實用,測試過程如下

1. 先看看基本狀況

➜  mephisto.cc git:(main) zpool list
NAME    SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
bpool  1.88G   244M  1.64G        -         -     1%    12%  1.00x    ONLINE  -
rpool   472G  23.1G   449G        -         -     3%     4%  1.00x    ONLINE  -
➜  mephisto.cc git:(main) zpool status
pool: bpool
state: ONLINE
config:

    NAME                                    STATE     READ WRITE CKSUM
    bpool                                   ONLINE       0     0     0
    5caca429-191c-f046-b1dc-3167ba2d43fa  ONLINE       0     0     0

errors: No known data errors

pool: rpool
state: ONLINE
config:

    NAME                                    STATE     READ WRITE CKSUM
    rpool                                   ONLINE       0     0     0
    1c85b674-1367-5d40-8553-2ba3439be776  ONLINE       0     0     0

errors: No known data errors
➜  mephisto.cc git:(main) zfs --version
zfs-2.1.2-1ubuntu3
zfs-kmod-2.1.2-1ubuntu3
➜  mephisto.cc git:(main) zfs list
NAME                                               USED  AVAIL     REFER  MOUNTPOINT
bpool                                              244M  1.51G       96K  /boot
bpool/BOOT                                         243M  1.51G       96K  none
bpool/BOOT/ubuntu_o54gp2                           243M  1.51G      243M  /boot
rpool                                             23.1G   434G       96K  /
rpool/ROOT                                        7.42G   434G       96K  none
rpool/ROOT/ubuntu_o54gp2                          7.42G   434G     5.74G  /
rpool/ROOT/ubuntu_o54gp2/srv                        96K   434G       96K  /srv
rpool/ROOT/ubuntu_o54gp2/usr                       140M   434G       96K  /usr
rpool/ROOT/ubuntu_o54gp2/usr/local                 139M   434G      139M  /usr/local
rpool/ROOT/ubuntu_o54gp2/var                      1.55G   434G       96K  /var
rpool/ROOT/ubuntu_o54gp2/var/games                  96K   434G       96K  /var/games
rpool/ROOT/ubuntu_o54gp2/var/lib                  1.51G   434G     1.38G  /var/lib
rpool/ROOT/ubuntu_o54gp2/var/lib/AccountsService   112K   434G      112K  /var/lib/AccountsService
rpool/ROOT/ubuntu_o54gp2/var/lib/NetworkManager    144K   434G      144K  /var/lib/NetworkManager
rpool/ROOT/ubuntu_o54gp2/var/lib/apt              84.4M   434G     84.4M  /var/lib/apt
rpool/ROOT/ubuntu_o54gp2/var/lib/dpkg             46.3M   434G     46.3M  /var/lib/dpkg
rpool/ROOT/ubuntu_o54gp2/var/log                  41.3M   434G     41.3M  /var/log
rpool/ROOT/ubuntu_o54gp2/var/mail                   96K   434G       96K  /var/mail
rpool/ROOT/ubuntu_o54gp2/var/snap                    1M   434G        1M  /var/snap
rpool/ROOT/ubuntu_o54gp2/var/spool                 116K   434G      116K  /var/spool
rpool/ROOT/ubuntu_o54gp2/var/www                    96K   434G       96K  /var/www
rpool/USERDATA                                    15.7G   434G       96K  /
rpool/USERDATA/mephisto_fmrvh5                    15.7G   434G     15.7G  /home/mephisto
rpool/USERDATA/root_fmrvh5                        1.03M   434G     1.03M  /root

2. 確認測試文件404.jpg存在

➜  mephisto.cc git:(main) ls -al ~/Pictures/iPhone 
total 47
drwxrwxrwx 2 mephisto mephisto     3 May 29 12:53 .
drwxrwxrwx 4 mephisto mephisto     7 May 26 14:49 ..
-rw-rw-r-- 1 mephisto mephisto 43408 May 29 12:53 404.jpg

3. 創建鏡像,然後刪除文件, 創建鏡像非常快,秒級

➜  mephisto.cc git:(main) sudo zfs snapshot rpool/USERDATA/[email protected]
[sudo] password for mephisto: 
➜  mephisto.cc git:(main) rm ~/Pictures/iPhone/404.jpg          
➜  mephisto.cc git:(main) ls  ~/Pictures/iPhone/404.jpg
ls: cannot access '/home/mephisto/Pictures/iPhone/404.jpg': No such file or directory

4. 再回滾鏡像,搶救被刪除的404.jpg,實測回滾也非常快,畢竟改動少

➜  mephisto.cc git:(main) sudo zfs rollback rpool/USERDATA/[email protected]
➜  mephisto.cc git:(main) ls ~/Pictures/iPhone/404.jpg                      
/home/mephisto/Pictures/iPhone/404.jpg
➜  mephisto.cc git:(main) echo "nubility"
nubility

5. 查看當前有哪些快照,9527就是剛剛創建的

➜  mephisto.cc git:(main) zfs list -t snapshot
NAME                                  USED  AVAIL     REFER  MOUNTPOINT
rpool/USERDATA/[email protected]  3.17M      -     15.7G  -

6. 再創建個9528的快照, 不重複測試了,文件系統還是很靠譜的

➜  mephisto.cc git:(main) sudo zfs snapshot rpool/USERDATA/[email protected]
[sudo] password for mephisto: 
➜  mephisto.cc git:(main) ✗ zfs list -t snapshot                                 
NAME                                  USED  AVAIL     REFER  MOUNTPOINT
rpool/USERDATA/[email protected]  3.98M      -     15.7G  -
rpool/USERDATA/[email protected]     0B      -     15.7G  -

另外,zfs的存儲池zpools也很好使用,不需要額外的卷管理系統去使用一個以上的設備,個人創建NAS的時可用上,因爲沒有額外的磁盤進行測試,有條件的用戶可以查閱OpenZFS或者Oracle的相關文檔進行操作

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