邏輯卷快照
lvcreate -L 128M -s -n lv1-snap /dev/vg1/lv1
lvs
lvscan
mount -o ro /dev/vg1/lv1 /mmt/lv1-snap
dmsetup ls --tree
測試
lvs /dev/vg1/lv1-snap
dd if=/dev/zero of=/uc1/test bs=1M count=40
lvs /dev/vg1/lv1-snap
問題
[root@web ~]# cd /mnt
[root@web mnt]# mkdir lv1-snap
mkdir: 無法創建目錄"lv1-snap": 只讀文件系統
記錄
root@192.168.235.20's password:┌────────────────────────────────────────────────────────────────────┐│ ? MobaXterm 20.0 ? ││ (SSH client, X-server and networking tools) ││ ││ ? SSH session to root@192.168.235.20 ││ ? SSH compression : ? ││ ? SSH-browser : ? ││ ? X11-forwarding : ? (remote display is forwarded through SSH) ││ ? DISPLAY : ? (automatically set on remote server) ││ ││ ? For more info, ctrl+click on help or visit our website │└────────────────────────────────────────────────────────────────────┘Last login: Mon Jul 21 19:45:22 2025 from 192.168.235.1
[root@web ~]# lvsWARNING: Device for PV r1noGN-Dn5A-udh3-qROp-C2Tj-HSil-AMqIZX not found or rejected by a filter.Couldn't find device with uuid r1noGN-Dn5A-udh3-qROp-C2Tj-HSil-AMqIZX.LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convertroot centos -wi-ao---- <17.00gswap centos -wi-ao---- 2.00glv01 vg01 -wi-a----- <3.09glv02 vg01 -wi-a----- 120.00mlv03 vg01 -wi-a----- 36.00mlv1 vg1 rwi-aor-r- 1.50g 100.00lv7 vg7 -wi-ao---- <2.10glv8 vg7 -wi-a----- 1.20glv_mysql vg_mysql -wi-ao---- 8.00g
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[root@web ~]# lvcreate -L 128M -s -n lv1-snap /dev/vg1/lv1Logical volume "lv1-snap" created.
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[root@web ~]# ls /mnt/lv2-snap
ls: 無法訪問/mnt/lv2-snap: 沒有那個文件或目錄
[root@web ~]# ls /mnt/lv1-sanp
ls: 無法訪問/mnt/lv1-sanp: 沒有那個文件或目錄
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[root@web ~]# ls /mnt/lv1-snap
ls: 無法訪問/mnt/lv1-snap: 沒有那個文件或目錄
[root@web ~]# mkdir -p /mnt/lv1-snap
mkdir: 無法創建目錄"/mnt/lv1-snap": 只讀文件系統
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[root@web ~]# mount -o ro /dev/vg1/lv1-snap /mnt/lv1-snap/
mount: 掛載點 /mnt/lv1-snap/ 不存在
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[root@web ~]# ll -d /mnt
drwxr-xr-x 8 root root 2048 11月 4 2020 /mnt
[root@web ~]#
[root@web ~]# ls /mnt/lv1-snpa
ls: 無法訪問/mnt/lv1-snpa: 沒有那個文件或目錄
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[root@web ~]# cd /mnt
[root@web mnt]# mkdir lv1-snap
mkdir: 無法創建目錄"lv1-snap": 只讀文件系統
[root@web mnt]# mount -o remount,rw /mnt
mount: 無法以讀寫方式重新掛載 /dev/sr0，它是寫保護的
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[root@web mnt]# mkdir -p /mmt/lv1-snap
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[root@web mnt]# mount -o ro /dev/vg1/lv1-snap /mmt/lv1-snap
[root@web mnt]# lvscanACTIVE Original '/dev/vg1/lv1' [1.50 GiB] inheritACTIVE Snapshot '/dev/vg1/lv1-snap' [128.00 MiB] inheritWARNING: Device for PV r1noGN-Dn5A-udh3-qROp-C2Tj-HSil-AMqIZX not found or rejected by a filter.Couldn't find device with uuid r1noGN-Dn5A-udh3-qROp-C2Tj-HSil-AMqIZX.ACTIVE '/dev/centos/swap' [2.00 GiB] inheritACTIVE '/dev/centos/root' [<17.00 GiB] inheritACTIVE '/dev/vg01/lv01' [<3.09 GiB] inheritACTIVE '/dev/vg01/lv02' [120.00 MiB] inheritACTIVE '/dev/vg01/lv03' [36.00 MiB] inheritACTIVE '/dev/vg7/lv7' [<2.10 GiB] inheritACTIVE '/dev/vg7/lv8' [1.20 GiB] inheritACTIVE '/dev/vg_mysql/lv_mysql' [8.00 GiB] inherit
[root@web mnt]# dmsetup ls --tree
vg7-lv8 (253:8)└─ (8:56)
vg7-lv7 (253:7)├─ (8:56)└─ (8:55)
vg_mysql-lv_mysql (253:2)├─ (8:39)├─ (8:38)├─ (8:37)├─ (8:34)└─ (8:33)
vg1-lv1 (253:12)└─vg1-lv1-real (253:13)├─vg1-lv1_rimage_1 (253:11)│ └─ (8:50)├─vg1-lv1_rmeta_1 (253:10)│ └─ (8:50)├─vg1-lv1_rimage_0 (253:9)└─vg1-lv1_rmeta_0 (253:6)
vg01-lv03 (253:5)└─ (8:23)
vg01-lv02 (253:4)└─ (8:23)
vg1-lv1--snap (253:15)├─vg1-lv1--snap-cow (253:14)│ └─ (8:50)└─vg1-lv1-real (253:13)├─vg1-lv1_rimage_1 (253:11)│ └─ (8:50)├─vg1-lv1_rmeta_1 (253:10)│ └─ (8:50)├─vg1-lv1_rimage_0 (253:9)└─vg1-lv1_rmeta_0 (253:6)
vg01-lv01 (253:3)├─ (8:21)├─ (8:24)├─ (8:23)└─ (8:22)
centos-swap (253:1)└─ (8:2)
centos-root (253:0)└─ (8:2)
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[root@web mnt]# df -h
文件系統 容量 已用 可用 已用% 掛載點
devtmpfs 470M 0 470M 0% /dev
tmpfs 487M 0 487M 0% /dev/shm
tmpfs 487M 33M 454M 7% /run
tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/mapper/centos-root 17G 17G 633M 97% /
/dev/sda1 1014M 172M 843M 17% /boot
/dev/sdb2 976M 2.6M 907M 1% /u2
/dev/sr0 4.4G 4.4G 0 100% /mnt
tmpfs 98M 12K 98M 1% /run/user/42
tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/vg7-lv7 2.1G 6.0M 2.0G 1% /u7
/dev/mapper/vg_mysql-lv_mysql 7.8G 1.2G 6.2G 17% /usr/local/mysql
/dev/mapper/vg1-lv1 1.5G 4.6M 1.4G 1% /uc1
/dev/mapper/vg1-lv1--snap 1.5G 4.6M 1.4G 1% /mmt/lv1-snap
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[root@web mnt]# dd if=/dev/zero of=/uc1/test bs=1M count=30
記錄了30+0 的讀入
記錄了30+0 的寫出
31457280字節(31 MB)已復制，0.116695 秒，270 MB/秒
[root@web mnt]# lvs /dev/vg1/lv1-snapLV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convertlv1-snap vg1 swi-aos--- 128.00m lv1 23.59
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[root@web mnt]# lvs /dev/vg1/lv1-snapLV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convertlv1-snap vg1 swi-aos--- 128.00m lv1 23.59
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[root@web mnt]# mount -o nouuid,ro /dev/vg1/lv1-snap /mmt/lv1-snap/s
mount: 掛載點 /mmt/lv1-snap/s 不存在
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[root@web mnt]# vim /etc/fstab
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[root@web mnt]# lvsWARNING: Device for PV r1noGN-Dn5A-udh3-qROp-C2Tj-HSil-AMqIZX not found or rejected by a filter.Couldn't find device with uuid r1noGN-Dn5A-udh3-qROp-C2Tj-HSil-AMqIZX.LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convertroot centos -wi-ao---- <17.00gswap centos -wi-ao---- 2.00glv01 vg01 -wi-a----- <3.09glv02 vg01 -wi-a----- 120.00mlv03 vg01 -wi-a----- 36.00mlv1 vg1 owi-aor-r- 1.50g 100.00lv1-snap vg1 swi-aos--- 128.00m lv1 23.59lv7 vg7 -wi-ao---- <2.10glv8 vg7 -wi-a----- 1.20glv_mysql vg_mysql -wi-ao---- 8.00g
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[root@web mnt]#
