1.分區
1.dd if=/dev/zero of=loop.img bs=1M count=200
2.losetup -a 當前正在使用的loop設備
losetup -f 可用的loop設備
losetup -d /dev/loop0 可刪除設備
[root@oc7067507274 ~]# losetup -f
/dev/loop0
3.losetup /dev/loop0 /root/loop.img
[root@oc7067507274 ~]# losetup /dev/loop0 /root/loop.img
[root@oc7067507274 ~]# losetup -a
/dev/loop0: [64770]:11927883 (/root/loop.img)
4.
Disk /dev/loop0: 209 MB, 209715200 bytes, 409600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0c19f915
Device Boot Start End Blocks Id System
/dev/loop0p1 2048 206847 102400 8e Linux LVM
/dev/loop0p2 206848 391167 92160 8e Linux LVM
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 22: Invalid argument.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
5.
[root@oc7067507274 ~]# partprobe /dev/loop0
[root@oc7067507274 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 200M 0 loop
├─loop0p1 259:3 0 100M 0 loop
└─loop0p2 259:4 0 90M 0 loop
nvme0n1 259:0 0 238.5G 0 disk
├─nvme0n1p1 259:1 0 1000M 0 part /boot
└─nvme0n1p2 259:2 0 237.5G 0 part
└─luks-a8057c53-b197-4918-a975-0656396b0c43 253:0 0 237.5G 0 crypt
├─vg_oc3573808223-lv_swap 253:1 0 12G 0 lvm [SWAP]
└─vg_oc3573808223-lv_root 253:2 0 225.5G 0 lvm /
2.pvcreate
6.[root@oc7067507274 ~]# pvcreate /dev/loop0p1 /dev/loop0p2
Physical volume "/dev/loop0p1" successfully created.
Physical volume "/dev/loop0p2" successfully created.
[root@oc7067507274 mapper]# pvs
PV VG Fmt Attr PSize PFree
/dev/loop0p1 lvm2 --- 100.00m 100.00m
/dev/loop0p2 lvm2 --- 90.00m 90.00m
3.vgcreate
7.[root@oc7067507274 mapper]# vgcreate vg_test /dev/loop0p1 /dev/loop0p2
Volume group "vg_test" successfully created
[root@oc7067507274 mapper]# vgs
VG #PV #LV #SN Attr VSize VFree
vg_oc3573808223 1 2 0 wz--n- 237.49g 0
vg_test 2 0 0 wz--n- 184.00m 184.00m
[root@oc7067507274 mapper]# vgdisplay vg_test
--- Volume group ---
VG Name vg_test
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 184.00 MiB
PE Size 4.00 MiB
Total PE 46
Alloc PE / Size 0 / 0
Free PE / Size 46 / 184.00 MiB
VG UUID 0vG29u-nRZV-vM9P-B2nJ-GWfc-QPpr-CYqgNy
4.mirror的LVM
[root@oc7067507274 mapper]# lvcreate -L 30M -m1 -n mirror_lvm vg_test
Rounding up size to full physical extent 32.00 MiB
Logical volume "mirror_lvm" created.
[root@oc7067507274 mapper]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 200M 0 loop
├─loop0p1 259:3 0 100M 0 loop
│ ├─vg_test-mirror_lvm_rmeta_0 253:3 0 4M 0 lvm
│ │ └─vg_test-mirror_lvm 253:7 0 32M 0 lvm
│ └─vg_test-mirror_lvm_rimage_0 253:4 0 32M 0 lvm
│ └─vg_test-mirror_lvm 253:7 0 32M 0 lvm
└─loop0p2 259:4 0 90M 0 loop
├─vg_test-mirror_lvm_rmeta_1 253:5 0 4M 0 lvm
│ └─vg_test-mirror_lvm 253:7 0 32M 0 lvm
└─vg_test-mirror_lvm_rimage_1 253:6 0 32M 0 lvm
└─vg_test-mirror_lvm 253:7 0 32M 0 lvm
[root@oc7067507274 mapper]# lvdisplay /dev/vg_test/mirror_lvm -m
--- Logical volume ---
LV Path /dev/vg_test/mirror_lvm
LV Name mirror_lvm
VG Name vg_test
LV UUID F3iuTc-tBbQ-D2cj-yjWq-5N06-bcmX-8ypFal
LV Write Access read/write
LV Creation host, time oc7067507274.ibm.com, 2020-05-21 09:46:04 +0800
LV Status available
# open 0
LV Size 32.00 MiB
Current LE 8
Mirrored volumes 2
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:7
--- Segments ---
Logical extents 0 to 7:
Type raid1
Monitoring monitored
Raid Data LV 0
Logical volume mirror_lvm_rimage_0
Logical extents 0 to 7
Raid Data LV 1
Logical volume mirror_lvm_rimage_1
Logical extents 0 to 7
Raid Metadata LV 0 mirror_lvm_rmeta_0
Raid Metadata LV 1 mirror_lvm_rmeta_1
[root@oc7067507274 mapper]# vgs
VG #PV #LV #SN Attr VSize VFree
vg_oc3573808223 1 2 0 wz--n- 237.49g 0
vg_test 2 1 0 wz--n- 184.00m 112.00m
mkdir /mirrorlvm
mkfs.ext4 /dev/vg_test/mirror_lvm
mount /dev/vg_test/mirror_lvm /mirrorlvm
[root@oc7067507274 mirrorlvm]# lvs -a -o+devices
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert Devices
mirror_lvm vg_test rwi-aor--- 32.00m 100.00 mirror_lvm_rimage_0(0),mirror_lvm_rimage_1(0)
[mirror_lvm_rimage_0] vg_test iwi-aor--- 32.00m /dev/loop0p1(1)
[mirror_lvm_rimage_1] vg_test iwi-aor--- 32.00m /dev/loop0p2(1)
[mirror_lvm_rmeta_0] vg_test ewi-aor--- 4.00m /dev/loop0p1(0)
[mirror_lvm_rmeta_1] vg_test ewi-aor--- 4.00m /dev/loop0p2(0)
6.stripe的lvm
lvcreate -L 60M --stripes 2 --stripesize 256 -n stripe_lvm vg_test
[root@oc7067507274 mirrorlvm]# lvcreate -L 60M --stripes 2 -n stripe_lvm vg_test
Using default stripesize 64.00 KiB.
Rounding size 60.00 MiB (15 extents) up to stripe boundary size 64.00 MiB(16 extents).
Logical volume "stripe_lvm" created.
[root@oc7067507274 mirrorlvm]# lvdisplay /dev/vg_test/stripe_lvm -m
--- Logical volume ---
LV Path /dev/vg_test/stripe_lvm
LV Name stripe_lvm
VG Name vg_test
LV UUID YhKggD-52Vf-hROx-UL0t-HhTW-hkkS-yNeHLE
LV Write Access read/write
LV Creation host, time oc7067507274.ibm.com, 2020-05-21 10:03:56 +0800
LV Status available
# open 0
LV Size 64.00 MiB
Current LE 16
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 512
Block device 253:8
--- Segments ---
Logical extents 0 to 15:
Type striped
Stripes 2
Stripe size 64.00 KiB
Stripe 0:
Physical volume /dev/loop0p1
Physical extents 9 to 16
Stripe 1:
Physical volume /dev/loop0p2
Physical extents 9 to 16
此時的pvdisplay -m：
--- Physical volume ---
PV Name /dev/loop0p1
VG Name vg_test
PV Size 100.00 MiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 24
Free PE 7
Allocated PE 17
PV UUID tDimek-wOoy-mcYw-BMu0-Ja7t-HKvT-nMYgYG
--- Physical Segments ---
Physical extent 0 to 0:
Logical volume /dev/vg_test/mirror_lvm_rmeta_0
Logical extents 0 to 0
Physical extent 1 to 8:
Logical volume /dev/vg_test/mirror_lvm_rimage_0
Logical extents 0 to 7
Physical extent 9 to 16:
Logical volume /dev/vg_test/stripe_lvm
Logical extents 0 to 15
Physical extent 17 to 23:
FREE
--- Physical volume ---
PV Name /dev/loop0p2
VG Name vg_test
PV Size 90.00 MiB / not usable 2.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 22
Free PE 5
Allocated PE 17
PV UUID l1Jlg1-qmYR-0mrA-qPtA-O36D-zgIT-eV8hS1
--- Physical Segments ---
Physical extent 0 to 0:
Logical volume /dev/vg_test/mirror_lvm_rmeta_1
Logical extents 0 to 0
Physical extent 1 to 8:
Logical volume /dev/vg_test/mirror_lvm_rimage_1
Logical extents 0 to 7
Physical extent 9 to 16:
Logical volume /dev/vg_test/stripe_lvm
Logical extents 0 to 15
Physical extent 17 to 21:
FREE
[root@oc7067507274 mirrorlvm]# lvs -a -o+devices
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert Devices )
mirror_lvm vg_test rwi-aor--- 32.00m 100.00 mirror_lvm_rimage_0(0),mirror_lvm_rimage_1(0)
[mirror_lvm_rimage_0] vg_test iwi-aor--- 32.00m /dev/loop0p1(1)
[mirror_lvm_rimage_1] vg_test iwi-aor--- 32.00m /dev/loop0p2(1)
[mirror_lvm_rmeta_0] vg_test ewi-aor--- 4.00m /dev/loop0p1(0)
[mirror_lvm_rmeta_1] vg_test ewi-aor--- 4.00m /dev/loop0p2(0)
stripe_lvm vg_test -wi-a----- 64.00m /dev/loop0p1(9),/dev/loop0p2(9)