Logical Volume Management (LVM) is very powerful device mapper framework that provides logical volume management for Linux systems.
In this post I'll just present you the minimal commands that are required to make use of the storage that is added to OS. In my last post, I've written about how to add storage to guest OS running on a VirtualBox. It can be compared to the storage addition done at OS level in companies. Once the storage is provided to the OS (be it a single disk added or a chunk from SAN, etc.,), we will look at how to make the storage available at the Linux OS for usage.
The process will involve the below steps
- Create Linux LVM partition using fdisk
- Create physical volume
- Create Volume group
- Create Logical Volume
- Create file system (ext4 used in this example)
- Mount the FS
- Make the FS mount permanent
Explanation of commands (highlighted lines) used are provided as comment lines prior to the commands in the demo. A few notable result lines are also highlighted.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 | [root@12r1-rac2 ~]# #check for available File systems[root@12r1-rac2 ~]# df -hFilesystem Size Used Avail Use% Mounted on/dev/sda1 25G 6.0G 18G 26% /tmpfs 2.0G 0 2.0G 0% /dev/shm/dev/sda3 9.8G 5.9G 3.4G 64% /u01/dev/sda2 12G 4.9G 6.3G 44% /u02Oracle 500G 267G 234G 54% /media/sf_Oracle[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# #List disks available, o/p truncated for better viewing[root@12r1-rac2 ~]# fdisk -lDisk /dev/sdd: 5368 MB, 5368709120 bytes255 heads, 63 sectors/track, 652 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x5f998c79 Device Boot Start End Blocks Id System/dev/sdd1 1 652 5237158+ 83 Linux.........Sector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00056a91 Device Boot Start End Blocks Id System/dev/sda1 * 1 3264 26214400 83 Linux/dev/sda2 3264 4830 12579840 83 Linux/dev/sda3 4830 6136 10485760 83 Linux/dev/sda4 6136 6528 3147776 5 Extended/dev/sda5 6136 6528 3145728 82 Linux swap / SolarisDisk /dev/sde: 5368 MB, 5368709120 bytes255 heads, 63 sectors/track, 652 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0xf306e413 Device Boot Start End Blocks Id System/dev/sde1 1 652 5237158+ 83 LinuxDisk /dev/sdf: 32.2 GB, 32212254720 bytes255 heads, 63 sectors/track, 3916 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x9e53da19 Device Boot Start End Blocks Id System[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# #Format the newly added disk. [root@12r1-rac2 ~]# #I'm creating 2 primary partitions with 15GB each in total of 30GB disk[root@12r1-rac2 ~]# #Using n,p,1,1,+15G,n,p,2(default),1960(default),3916(default),w as input[root@12r1-rac2 ~]# #This step can be skipped if you want to partition while initializing using pvcreate[root@12r1-rac2 /]# fdisk /dev/sdfWARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u').Command (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 1First cylinder (1-3916, default 1):Using default value 1Last cylinder, +cylinders or +size{K,M,G} (1-3916, default 3916): +15GCommand (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 2First cylinder (1960-3916, default 1960):Using default value 1960Last cylinder, +cylinders or +size{K,M,G} (1960-3916, default 3916):Using default value 3916Command (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.Syncing disks.[root@12r1-rac2 /]#[root@12r1-rac2 ~]# #List the available disks. Newly created disks are visible, o/p truncated for better viewing[root@12r1-rac2 ~]# fdisk -lDisk /dev/sdd: 5368 MB, 5368709120 bytes255 heads, 63 sectors/track, 652 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x5f998c79 Device Boot Start End Blocks Id System/dev/sdd1 1 652 5237158+ 83 LinuxDisk /dev/sdc: 5368 MB, 5368709120 bytes........./dev/sda3 4830 6136 10485760 83 Linux/dev/sda4 6136 6528 3147776 5 Extended/dev/sda5 6136 6528 3145728 82 Linux swap / SolarisDisk /dev/sde: 5368 MB, 5368709120 bytes255 heads, 63 sectors/track, 652 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0xf306e413 Device Boot Start End Blocks Id System/dev/sde1 1 652 5237158+ 83 LinuxDisk /dev/sdf: 32.2 GB, 32212254720 bytes255 heads, 63 sectors/track, 3916 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x9e53da19 Device Boot Start End Blocks Id System/dev/sdf1 1 1959 15735636 83 Linux/dev/sdf2 1960 3916 15719602+ 83 Linux[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# #Change the partition type of /dev/sdf1, /dev/sdf2 to Linux LVM [root@12r1-rac2 ~]# #Using t,1,8e,t,2,8e,w as input[root@12r1-rac2 ~]# fdisk /dev/sdfWARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u').Command (m for help): tPartition number (1-4): 1Hex code (type L to list codes): 8eChanged system type of partition 1 to 8e (Linux LVM)Command (m for help): tPartition number (1-4): 2Hex code (type L to list codes): 8eChanged system type of partition 2 to 8e (Linux LVM)Command (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.Syncing disks.[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# #List the available disks, o/p truncated for better viewing[root@12r1-rac2 ~]# fdisk -lDisk /dev/sdd: 5368 MB, 5368709120 bytes255 heads, 63 sectors/track, 652 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x5f998c79 Device Boot Start End Blocks Id System/dev/sdd1 1 652 5237158+ 83 LinuxDisk /dev/sdc: 5368 MB, 5368709120 bytes.........Sector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0xf306e413 Device Boot Start End Blocks Id System/dev/sde1 1 652 5237158+ 83 LinuxDisk /dev/sdf: 32.2 GB, 32212254720 bytes255 heads, 63 sectors/track, 3916 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x9e53da19 Device Boot Start End Blocks Id System/dev/sdf1 1 1959 15735636 8e Linux LVM/dev/sdf2 1960 3916 15719602+ 8e Linux LVM[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# #Currently LVM is not configured in the system and hence no o/p for the below 3 commands[root@12r1-rac2 ~]# pvs[root@12r1-rac2 ~]# vgs[root@12r1-rac2 ~]# lvs[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# #Create physical volumes using available disks. (also used to format block device if not formatted already)[root@12r1-rac2 ~]# pvcreate /dev/sdf1 /dev/sdf2 Physical volume "/dev/sdf1" successfully created Physical volume "/dev/sdf2" successfully created[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# #List the physical volumes, you can use 'pvdisplay' command to view detailed information[root@12r1-rac2 ~]# pvs PV VG Fmt Attr PSize PFree /dev/sdf1 lvm2 --- 15.01g 15.01g /dev/sdf2 lvm2 --- 14.99g 14.99g[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# #Create Volume Group (named vg18c) using the available PVs [root@12r1-rac2 ~]# vgcreate vg18c /dev/sdf1 /dev/sdf2 Volume group "vg18c" successfully created[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# #List available VGs, #PV denotes 2 PVs associated with this VG. [root@12r1-rac2 ~]# #Use 'vgdisplay' command to view detailed information[root@12r1-rac2 ~]# vgs VG #PV #LV #SN Attr VSize VFree vg18c 2 0 0 wz--n- 29.99g 29.99g[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# #Create Logical Volume from the available VG[root@12r1-rac2 ~]# # -L is size and -n is name. Last variable is the VG, the LV will be created from.[root@12r1-rac2 ~]# lvcreate -L 12G -n 18cgrid vg18c Logical volume "18cgrid" created.[root@12r1-rac2 ~]# lvcreate -L 12G -n 18cdb vg18c Logical volume "18cdb" created.[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# #List the LVs. Use 'lvdisplay' to view detailed information[root@12r1-rac2 ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert 18cdb vg18c -wi-a----- 12.00g 18cgrid vg18c -wi-a----- 12.00g[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# #Now create File system of type ext4 with the available LV using mkfs command[root@12r1-rac2 ~]# mkfs -t ext4 /dev/vg18c/18cdbmke2fs 1.43-WIP (20-Jun-2013)Filesystem label=OS type: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks786432 inodes, 3145728 blocks157286 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=322122547296 block groups32768 blocks per group, 32768 fragments per group8192 inodes per groupSuperblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208Allocating group tables: doneWriting inode tables: doneCreating journal (32768 blocks): doneWriting superblocks and filesystem accounting information: done[root@12r1-rac2 ~]# mkfs -t ext4 /dev/vg18c/18cgridmke2fs 1.43-WIP (20-Jun-2013)Filesystem label=OS type: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks786432 inodes, 3145728 blocks157286 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=322122547296 block groups32768 blocks per group, 32768 fragments per group8192 inodes per groupSuperblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208Allocating group tables: doneWriting inode tables: doneCreating journal (32768 blocks): doneWriting superblocks and filesystem accounting information: done[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# mkdir /oradir1 /oradir2[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# #Mount the FS using mount command[root@12r1-rac2 ~]# mount /dev/vg18c/18cgrid /oradir1[root@12r1-rac2 ~]# mount /dev/vg18c/18cdb /oradir2[root@12r1-rac2 ~]# df -hFilesystem Size Used Avail Use% Mounted on/dev/sda1 25G 6.0G 18G 26% /tmpfs 2.0G 629M 1.4G 32% /dev/shm/dev/sda3 9.8G 5.9G 3.4G 64% /u01/dev/sda2 12G 4.9G 6.3G 44% /u02Oracle 500G 267G 234G 54% /media/sf_Oracle/dev/mapper/vg18c-18cgrid 12G 30M 12G 1% /oradir1/dev/mapper/vg18c-18cdb 12G 30M 12G 1% /oradir2[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# #Edit the fstab to make the mount permanent across reboots. [root@12r1-rac2 ~]# vi /etc/fstab[root@12r1-rac2 ~]#[root@12r1-rac2 ~]#[root@12r1-rac2 ~]# cat /etc/fstab## /etc/fstab# Created by anaconda on Tue Oct 20 01:50:26 2015## Accessible filesystems, by reference, are maintained under '/dev/disk'# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info#UUID=b149969c-329d-48d7-ace0-ea7ac6671964 / ext4 defaults 1 1UUID=aa9b0bed-4eab-407d-8c0f-c2739a7678fb /u01 ext4 defaults 1 2UUID=2ab60579-5059-4c1e-9db1-7ac8d9a5ac77 /u02 ext4 defaults 1 2UUID=6ebf30ec-79d9-4c54-8e44-ce7f47190fdd swap swap defaults 0 0tmpfs /dev/shm tmpfs defaults 0 0devpts /dev/pts devpts gid=5,mode=620 0 0sysfs /sys sysfs defaults 0 0proc /proc proc defaults 0 0/dev/mapper/vg18c-18cgrid /oradir1 ext4 defaults 0 0/dev/mapper/vg18c-18cdb /oradir2 ext4 defaults 0 0[root@12r1-rac2 ~]# [root@12r1-rac2 ~]# |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | [root@12r1-rac2 /]# #Make sure to umount the file system. [root@12r1-rac2 /]# umount /dev/mapper/vg18c-18cgrid[root@12r1-rac2 /]# umount /dev/mapper/vg18c-18cdb[root@12r1-rac2 /]# df -hFilesystem Size Used Avail Use% Mounted on/dev/sda1 25G 5.1G 19G 22% /tmpfs 2.0G 633M 1.4G 32% /dev/shm/dev/sda3 9.8G 5.9G 3.4G 64% /u01/dev/sda2 12G 4.9G 6.3G 44% /u02Oracle 500G 268G 233G 54% /media/sf_Oracle[root@12r1-rac2 /]# [root@12r1-rac2 /]# #Remove the logical volume[root@12r1-rac2 /]# lvremove /dev/mapper/vg18c-18cgridDo you really want to remove active logical volume 18cgrid? [y/n]: y Logical volume "18cgrid" successfully removed[root@12r1-rac2 /]# lvremove /dev/mapper/vg18c-18cdbDo you really want to remove active logical volume 18cdb? [y/n]: y Logical volume "18cdb" successfully removed[root@12r1-rac2 /]#[root@12r1-rac2 /]#[root@12r1-rac2 /]# #Remove the volume group[root@12r1-rac2 /]# vgremove vg18c Volume group "vg18c" successfully removed[root@12r1-rac2 /]# [root@12r1-rac2 /]# [root@12r1-rac2 /]# #Remove the Physical volumes created[root@12r1-rac2 /]# pvremove /dev/sdf1 /dev/sdf2 Labels on physical volume "/dev/sdf1" successfully wiped Labels on physical volume "/dev/sdf2" successfully wiped[root@12r1-rac2 /]#[root@12r1-rac2 /]# |
Great post and informative blog. it was awesome to read, thanks for sharing
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