Table of Contents
File System Management
1. Creating a file system without LVM
1.1. Display information about a free disk ("vdb"):
# fdisk -l Disk /dev/vda: 10.5 GB, 10522670080 bytes, 20552090 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: 0x00002d39 Device Boot Start End Blocks Id System /dev/vda1 * 2048 1050623 524288 83 Linux /dev/vda2 1050624 20551679 9750528 8e Linux LVM ... Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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
or
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11:0 1 1024M 0 rom vda 252:0 0 9.8G 0 disk ├─vda1 252:1 0 512M 0 part /boot └─vda2 252:2 0 9.3G 0 part ├─vg00-root_lv 253:0 0 1G 0 lvm / ├─vg00-swap_lv 253:1 0 1G 0 lvm [SWAP] ├─vg00-usr_lv 253:2 0 4.8G 0 lvm /usr ├─vg00-var_lv 253:3 0 1G 0 lvm /var ├─vg00-tmp_lv 253:4 0 1G 0 lvm /tmp └─vg00-home_lv 253:5 0 512M 0 lvm /home vdb 252:16 0 10G 0 disk
1.2. Create a primary partition on the disk that is 5 GB in size:
# fdisk /dev/vdb
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0x610c7c18.
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): +5G
Partition 1 of type Linux and of size 5 GiB is set
Command (m for help): p
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x610c7c18
Device Boot Start End Blocks Id System
/dev/vdb1 2048 10487807 5242880 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
1.3. Optionally verify that the partition has been created:
# fdisk -l /dev/vdb Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0xefe0464f Device Boot Start End Blocks Id System /dev/vdb1 2048 10487807 5242880 83 Linux
1.4. Inform the OS of partition table changes:
# partprobe
1.5. Format the partition with the XFS file system:
# mkfs.xfs /dev/vdb1
meta-data=/dev/vdb1 isize=512 agcount=4, agsize=327680 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=1310720, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
1.6. Create a mount point for the file system:
# mkdir /projects
1.7. Display the UUID of the partition:
# blkid /dev/vdb1 /dev/vdb1: UUID="d031e078-6d95-47ae-8d21-c955d841cf0e" TYPE="xfs"
1.8. Edit /etc/fstab to make the file system available permanently:
# echo 'UUID=d031e078-6d95-47ae-8d21-c955d841cf0e /projects xfs defaults 0 0' >> /etc/fstab
1.9. Update systemd with the new /etc/fstab configuration (RHEL/CentOS 7/8):
# systemctl daemon-reload
1.10. Mount the file system:
# mount /projects
1.11. Verify that the new file system is mounted:
# df -h /projects Filesystem Size Used Avail Use% Mounted on /dev/vdb1 5.0G 33M 5.0G 1% /projects
2. Removing a file system without LVM
2.1. Umount the "/projects" file system:
# umount /projects
2.2. Remove the mount point:
# rmdir /projects
2.3. Remove the entry from /etc/fstab:
# sed -i '/projects/d' /etc/fstab
2.4. Update systemd with the new /etc/fstab configuration (RHEL/CentOS 7/8):
# systemctl daemon-reload
2.5. Remove the partition:
# fdisk /dev/vdb Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help): d Selected partition 1 Partition 1 is deleted Command (m for help): p Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x610c7c18 Device Boot Start End Blocks Id System Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
2.6. Optionally verify that the partition has been removed:
# fdisk -l /dev/vdb Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0xefe0464f Device Boot Start End Blocks Id System
2.7. Inform the OS of partition table changes:
# partprobe
2.8. Verify that the file system does not exist:
# df -h /projects df: ‘/projects’: No such file or directory
3. Creating a file system within LVM
3.1. Creating a single file system
3.1.1. Display information about a free disk "vdb":
# fdisk -l /dev/vdb Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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
or
# lsblk /dev/vdb NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT vdb 252:16 0 10G 0 disk
3.1.2. Create a primary partition of type "Linux LVM" across the entire disk (or continue directly with the "pvcreate" command below and use the entire disk):
# fdisk /dev/vdb
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519):
Using default value 20971519
Partition 1 of type Linux and of size 10 GiB is set
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): L
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx
5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data
6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility
8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt
9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
1e Hidden W95 FAT1 80 Old Minix
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x610c7c18
Device Boot Start End Blocks Id System
/dev/vdb1 2048 20971519 10484736 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
3.1.3. Optionally verify that the partition has been created:
# fdisk -l /dev/vdb Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x610c7c18 Device Boot Start End Blocks Id System /dev/vdb1 2048 20971519 10484736 8e Linux LVM
3.1.4. Inform the OS of partition table changes:
# partprobe
3.1.5. Create a physical volume from the partition that will be used within LVM:
# pvcreate /dev/vdb1 Physical volume "/dev/vdb1" successfully created.
3.1.6. Create a volume group "data_vg" from the physical volume:
# vgcreate data_vg /dev/vdb1 Volume group "data_vg" successfully created
3.1.7. Create a 2 GB logical volume "data1_lv" in the volume group:
# lvcreate -n data1_lv -L 2G data_vg Logical volume "data1_lv" created.
3.1.8. Format the logical volume with the XFS file system:
# mkfs.xfs /dev/data_vg/data1_lv
meta-data=/dev/data_vg/data1_lv isize=512 agcount=4, agsize=131072 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=524288, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
3.1.9. Create a mount point for the file system:
# mkdir /data1
3.1.10. Edit /etc/fstab to make the file system available permanently:
# echo '/dev/mapper/data_vg-data1_lv /data1 xfs defaults 0 0' >> /etc/fstab
3.1.11. Update systemd with the new /etc/fstab configuration (RHEL/CentOS 7/8):
# systemctl daemon-reload
3.1.12. Mount the file system:
# mount /data1
3.1.13. Verify that the new file system is mounted:
# df -h /data1 Filesystem Size Used Avail Use% Mounted on /dev/mapper/data_vg-data1_lv 2.0G 33M 2.0G 2% /data1
3.2. Creating multiple file systems
3.2.1. Create logical volumes, file systems and mount points of the specified parameters:
# echo "data2_lv /data2 xfs 2G data_vg
data3_lv /data3 xfs 2G data_vg
data4_lv /data4 xfs 2G data_vg
data5_lv /data5 xfs 2G data_vg" | while read a b c d e; do lvcreate -n $a -L $d $e; mkfs.xfs /dev/mapper/${e}-$a; mkdir -p $b; echo "/dev/mapper/${e}-$a $b $c defaults 0 0" >> /etc/fstab; done
3.2.2. Update systemd with the new /etc/fstab configuration (RHEL/CentOS 7/8):
# systemctl daemon-reload
3.2.3. Mount the file systems:
# mount -a
3.2.4. Verify that the new file systems are mounted:
# df -h /data* Filesystem Size Used Avail Use% Mounted on /dev/mapper/data_vg-data1_lv 2.0G 33M 2.0G 2% /data1 /dev/mapper/data_vg-data2_lv 2.0G 33M 2.0G 2% /data2 /dev/mapper/data_vg-data3_lv 2.0G 33M 2.0G 2% /data3 /dev/mapper/data_vg-data4_lv 2.0G 33M 2.0G 2% /data4 /dev/mapper/data_vg-data5_lv 2.0G 33M 2.0G 2% /data5
4. Extending a file system within LVM
4.1. After adding a disk
4.1.1. Verify if there is enough free space to extend the logical volume in the volume group ("data_vg"):
# vgs VG #PV #LV #SN Attr VSize VFree data_vg 1 5 0 wz--n- <10.00g 0 vg00 1 6 0 wz--n- <9.30g 0
4.1.2. If there is not enough space in the volume group, add a new disk.
4.1.2.1. Find out the type of the logical volume (pay special attention to the "striped" or "mirrored" type):
# lvs -a -o segtype,devices,lv_name,vg_name | grep data5_lv linear /dev/vdb1(2048) data5_lv data_vg
4.1.2.2. If a SCSI disk has been added and has not been automatically detected by the system, force it to load:
# rescan-scsi-bus.sh -a
or
# for host in $(ls -1d /sys/class/scsi_host/*); do echo "- - -" > ${host}/scan; done
4.1.2.3. Display information about the added disk ("vdc"):
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11:0 1 1024M 0 rom vda 252:0 0 9.8G 0 disk ├─vda1 252:1 0 512M 0 part /boot └─vda2 252:2 0 9.3G 0 part ├─vg00-root_lv 253:0 0 1G 0 lvm / ├─vg00-swap_lv 253:1 0 1G 0 lvm [SWAP] ├─vg00-usr_lv 253:2 0 4.8G 0 lvm /usr ├─vg00-var_lv 253:3 0 1G 0 lvm /var ├─vg00-tmp_lv 253:4 0 1G 0 lvm /tmp └─vg00-home_lv 253:5 0 512M 0 lvm /home vdb 252:16 0 10G 0 disk └─vdb1 252:17 0 10G 0 part ├─data_vg-data1_lv 253:6 0 2G 0 lvm /data1 ├─data_vg-data2_lv 253:7 0 2G 0 lvm /data2 ├─data_vg-data3_lv 253:8 0 2G 0 lvm /data3 ├─data_vg-data4_lv 253:9 0 2G 0 lvm /data4 └─data_vg-data5_lv 253:10 0 2G 0 lvm /data5 vdc 252:32 0 10G 0 disk
4.1.2.4. Create a physical volume from the disk that will be used within LVM:
# pvcreate /dev/vdc Physical volume "/dev/vdc" successfully created.
4.1.2.5. Add the physical volume to the specified volume group ("data_vg"):
# vgextend data_vg /dev/vdc Volume group "data_vg" successfully extended # vgs VG #PV #LV #SN Attr VSize VFree data_vg 2 5 0 wz--n- 20.00g <10.00g vg00 1 6 0 wz--n- <9.30g 0
4.1.3. Extend the logical volume with the "/data5" file system by 5 GB:
# lvresize -L +5G data_vg/data5_lv
Size of logical volume data_vg/data5_lv changed from <2.00 GiB (511 extents) to <7.00 GiB (1791 extents).
Logical volume data_vg/data5_lv successfully resized.
# xfs_growfs /dev/data_vg/data5_lv
meta-data=/dev/mapper/data_vg-data5_lv isize=512 agcount=4, agsize=130816 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=523264, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 523264 to 1833984
or
# lvresize -rL +5G data_vg/data5_lv
4.1.4. Verify that the file system size has changed:
# df -h /data5 Filesystem Size Used Avail Use% Mounted on /dev/mapper/data_vg-data5_lv 7.0G 33M 7.0G 1% /data5
4.2. After increasing a disk capacity
4.2.1. Verify if there is enough free space to extend the logical volume in the volume group ("data_vg"):
# vgs VG #PV #LV #SN Attr VSize VFree data_vg 1 5 0 wz--n- <10.00g 0 vg00 1 6 0 wz--n- <9.30g 0
4.2.2. If there is not enough space in the volume group, increase the disk capacity.
4.2.2.1. If a SCSI disk capacity has been increased and has not been automatically detected by the system, force it to load:
# rescan-scsi-bus.sh
or
# for disk in $(ls -1d /sys/class/scsi_disk/*); do echo "1" > ${disk}/device/rescan; done
4.2.2.2. Display information about the increased disk ("vdb"):
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11:0 1 1024M 0 rom vda 252:0 0 10.8G 0 disk ├─vda1 252:1 0 512M 0 part /boot └─vda2 252:2 0 9.3G 0 part ├─vg00-root_lv 253:0 0 1G 0 lvm / ├─vg00-swap_lv 253:1 0 1G 0 lvm [SWAP] ├─vg00-usr_lv 253:2 0 4.8G 0 lvm /usr ├─vg00-var_lv 253:5 0 1G 0 lvm /var ├─vg00-tmp_lv 253:9 0 1G 0 lvm /tmp └─vg00-home_lv 253:10 0 512M 0 lvm /home vdb 252:16 0 15G 0 disk └─vdb1 252:17 0 10G 0 part ├─data_vg-data1_lv 253:3 0 2G 0 lvm /data1 ├─data_vg-data2_lv 253:4 0 2G 0 lvm /data2 ├─data_vg-data3_lv 253:6 0 2G 0 lvm /data3 ├─data_vg-data4_lv 253:7 0 2G 0 lvm /data4 └─data_vg-data5_lv 253:8 0 2G 0 lvm /data5
4.2.2.3. Increase the capacity of the partition ("vdb1") by all the free space on the disk:
# parted /dev/vdb resizepart 1 100% Information: You may need to update /etc/fstab.
4.2.2.4. Verify that the partition ("vdb1") has been increased:
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11:0 1 1024M 0 rom vda 252:0 0 10.8G 0 disk ├─vda1 252:1 0 512M 0 part /boot └─vda2 252:2 0 9.3G 0 part ├─vg00-root_lv 253:0 0 1G 0 lvm / ├─vg00-swap_lv 253:1 0 1G 0 lvm [SWAP] ├─vg00-usr_lv 253:2 0 4.8G 0 lvm /usr ├─vg00-var_lv 253:5 0 1G 0 lvm /var ├─vg00-tmp_lv 253:9 0 1G 0 lvm /tmp └─vg00-home_lv 253:10 0 512M 0 lvm /home vdb 252:16 0 15G 0 disk └─vdb1 252:17 0 15G 0 part ├─data_vg-data1_lv 253:3 0 2G 0 lvm /data1 ├─data_vg-data2_lv 253:4 0 2G 0 lvm /data2 ├─data_vg-data3_lv 253:6 0 2G 0 lvm /data3 ├─data_vg-data4_lv 253:7 0 2G 0 lvm /data4 └─data_vg-data5_lv 253:8 0 2G 0 lvm /data5
4.2.2.5. Inform the OS of partition table changes:
# partprobe
4.2.2.6. Display the capacity of physical volumes:
# pvs PV VG Fmt Attr PSize PFree /dev/vda2 vg00 lvm2 a-- <9.30g 0 /dev/vdb1 data_vg lvm2 a-- <10.00g 0
4.2.2.7. Increase the capacity of the physical volume ("vdb1") by all the free space on the partition:
# pvresize /dev/vdb1 Physical volume "/dev/vdb1" changed 1 physical volume(s) resized or updated / 0 physical volume(s) not resized
4.2.2.8. Verify that the physical volume ("vdb1") has been increased:
# pvs PV VG Fmt Attr PSize PFree /dev/vda2 vg00 lvm2 a-- <9.30g 0 /dev/vdb1 data_vg lvm2 a-- <15.00g 5.00g # vgs VG #PV #LV #SN Attr VSize VFree data_vg 1 5 0 wz--n- <15.00g 5.00g vg00 1 6 0 wz--n- <9.30g 0
4.2.3. Extend the logical volume with the "/data5" file system by all the free space in the volume group:
# lvresize -l +100%FREE data_vg/data5_lv
Size of logical volume data_vg/data5_lv changed from <2.00 GiB (511 extents) to <7.00 GiB (1791 extents).
Logical volume data_vg/data5_lv successfully resized.
# xfs_growfs /dev/data_vg/data5_lv
meta-data=/dev/mapper/data_vg-data5_lv isize=512 agcount=4, agsize=130816 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=523264, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 523264 to 1833984
or
# lvresize -rl +100%FREE data_vg/data5_lv
4.2.4. Verify that the file system size has changed:
# df -h /data5 Filesystem Size Used Avail Use% Mounted on /dev/mapper/data_vg-data5_lv 7.0G 33M 7.0G 1% /data5
5. Removing a file system within LVM
5.1. Umount the "/data5" file system:
# umount /data5
5.2. Remove the mount point:
# rmdir /data5
5.3. Deactivate the logical volume:
# lvchange -a n data_vg/data5_lv
5.4. Remove the logical volume including the file system:
# lvremove data_vg/data5_lv Logical volume "data5_lv" successfully removed
5.5. Remove the entry from /etc/fstab:
# sed -i '/data5_lv/d' /etc/fstab
5.6. Update systemd with the new /etc/fstab configuration (RHEL/CentOS 7/8):
# systemctl daemon-reload
5.7. Verify that the file system does not exist:
# df -h /data5 df: ‘/data5’: No such file or directory
5.8. Optionally remove the unused disk from the system:
5.8.1. Remove the physical volume from the volume group (the physical volume must be empty):
# pvs PV VG Fmt Attr PSize PFree /dev/vda2 vg00 lvm2 a-- <9.30g 0 /dev/vdb1 data_vg lvm2 a-- <10.00g <2.00g /dev/vdc data_vg lvm2 a-- <10.00g <10.00g # vgreduce data_vg /dev/vdc Removed "/dev/vdc" from volume group "data_vg"
5.8.2. Remove the physical volume from LVM:
# pvremove /dev/vdc Labels on physical volume "/dev/vdc" successfully wiped.
5.8.3. Optionally remove the SCSI disk from the system:
# echo 1 > /sys/block/vdc/device/delete # lsblk /dev/vdc lsblk: /dev/vdc: not a block device
6. Restoring a file system within LVM
6.1. Create some data in the file system (for the example purpose):
# ls -l /data4 total 0 # echo "This is just the beginning." > /data4/test # ls -l /data4 total 4 -rw-r--r--. 1 root root 28 Feb 15 23:06 test
6.2. Accidentally remove the file system including the logical volume:
# umount /data4 # rmdir /data4 # lvremove data_vg/data4_lv Do you really want to remove active logical volume data_vg/data4_lv? [y/n]: y Logical volume "data4_lv" successfully removed
6.3. Examine the archive files for the "data_vg" volume group and locate the one that has a description of "Created *before* executing 'lvremove data_vg/data4_lv'":
# vgcfgrestore -l data_vg ... File: /etc/lvm/archive/data_vg_00030-1155990744.vg VG name: data_vg Description: Created *before* executing 'lvremove data_vg/data4_lv' Backup Time: Mon Feb 15 23:09:18 2021 File: /etc/lvm/backup/data_vg VG name: data_vg Description: Created *after* executing 'lvremove data_vg/data4_lv' Backup Time: Mon Feb 15 23:09:18 2021
6.4. Using the archive file, revert the operation "lvremove data_vg/data4_lv":
# vgcfgrestore -f /etc/lvm/archive/data_vg_00030-1155990744.vg data_vg
Volume group data_vg has active volume: data1_lv.
Volume group data_vg has active volume: data3_lv.
Volume group data_vg has active volume: data2_lv.
WARNING: Found 3 active volume(s) in volume group "data_vg".
Restoring VG with active LVs, may cause mismatch with its metadata.
Do you really want to proceed with restore of volume group "data_vg", while 3 volume(s) are active? [y/n]: n
Restore aborted.
# umount /data*
# lvchange -a n data_vg/data{1..3}_lv
# vgcfgrestore -f /etc/lvm/archive/data_vg_00030-1155990744.vg data_vg
Restored volume group data_vg
6.5. Recreate the mount point and reactivate the logical volumes:
# mkdir /data4
# lvchange -a y data_vg/data{1..4}_lv
# mount -a
# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
data1_lv data_vg -wi-ao---- 2.00g
data2_lv data_vg -wi-ao---- 2.00g
data3_lv data_vg -wi-ao---- 2.00g
data4_lv data_vg -wi-ao---- 2.00g
...
6.6. Verify the contents of the previously removed file system:
# ls -l /data4 total 4 -rw-r--r--. 1 root root 28 Feb 15 23:06 test # cat /data4/test This is just the beginning.
7. Managing file systems on a multipath device
7.1. Configuring device mapper multipath (FC SAN)
7.1.1. List the fibre channel host bus adapters (HBA):
# lspci | grep -i fibre 4b:00.0 Fibre Channel: Emulex Corporation LPe35000/LPe36000 Series 32Gb/64Gb Fibre Channel Adapter (rev 10) 4b:00.1 Fibre Channel: Emulex Corporation LPe35000/LPe36000 Series 32Gb/64Gb Fibre Channel Adapter (rev 10) 98:00.0 Fibre Channel: Emulex Corporation LPe35000/LPe36000 Series 32Gb/64Gb Fibre Channel Adapter (rev 10) 98:00.1 Fibre Channel: Emulex Corporation LPe35000/LPe36000 Series 32Gb/64Gb Fibre Channel Adapter (rev 10)
7.1.2. Check the port status of the fibre channel host bus adapters:
# grep -v "xyz" /sys/class/fc_host/host*/port_state /sys/class/fc_host/host15/port_state:Online /sys/class/fc_host/host16/port_state:Linkdown /sys/class/fc_host/host17/port_state:Online /sys/class/fc_host/host18/port_state:Linkdown
7.1.3. Print the world wide port name (WWPN) of the fibre channel host bus adapters needed for the storage request:
# grep -v "xyz" /sys/class/fc_host/host*/port_name /sys/class/fc_host/host15/port_name:0x100000109bef6c75 /sys/class/fc_host/host16/port_name:0x100000109bef6c76 /sys/class/fc_host/host17/port_name:0x100000109bef6cb1 /sys/class/fc_host/host18/port_name:0x100000109bef6cb2
7.1.4. Verify that a new disk (LUN) has been added from the storage (SAN):
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 1.8T 0 disk ├─sda1 8:1 0 256M 0 part /boot/efi ├─sda2 8:2 0 1G 0 part /boot └─sda3 8:3 0 68.8G 0 part ├─vg00-root_lv 253:0 0 3G 0 lvm / ├─vg00-swap_lv 253:1 0 4G 0 lvm [SWAP] ├─vg00-usr_lv 253:2 0 10G 0 lvm /usr ├─vg00-home_lv 253:3 0 3G 0 lvm /home ├─vg00-var_lv 253:4 0 5G 0 lvm /var ├─vg00-tmp_lv 253:5 0 5G 0 lvm /tmp └─vg00-opt_lv 253:6 0 2G 0 lvm /opt sdb 8:16 0 1T 0 disk sdc 8:32 0 1T 0 disk sdd 8:48 0 1T 0 disk sde 8:64 0 1T 0 disk # lsscsi -suvw [0:0:68:0] enclosu 300705b011bc7cc0 - - dir: /sys/bus/scsi/devices/0:0:68:0 [/sys/devices/pci0000:30/0000:30:02.0/0000:31:00.0/host0/target0:0:68/0:0:68:0] [0:2:0:0] disk 600605b011bc7cc029fa6b79195b44d5 0x600605b011bc7cc029fa6b79195b44d5 /dev/sda 1.91TB dir: /sys/bus/scsi/devices/0:2:0:0 [/sys/devices/pci0000:30/0000:30:02.0/0000:31:00.0/host0/target0:2:0/0:2:0:0] [15:0:12:0] disk 60050764008101956000000000000239 /dev/sdb 1.09TB dir: /sys/bus/scsi/devices/15:0:12:0 [/sys/devices/pci0000:4a/0000:4a:02.0/0000:4b:00.0/host15/rport-15:0-21/target15:0:12/15:0:12:0] [15:0:13:0] disk 60050764008101956000000000000239 /dev/sdc 1.09TB dir: /sys/bus/scsi/devices/15:0:13:0 [/sys/devices/pci0000:4a/0000:4a:02.0/0000:4b:00.0/host15/rport-15:0-22/target15:0:13/15:0:13:0] [17:0:12:0] disk 60050764008101956000000000000239 /dev/sdd 1.09TB dir: /sys/bus/scsi/devices/17:0:12:0 [/sys/devices/pci0000:97/0000:97:02.0/0000:98:00.0/host17/rport-17:0-21/target17:0:12/17:0:12:0] [17:0:13:0] disk 60050764008101956000000000000239 /dev/sde 1.09TB dir: /sys/bus/scsi/devices/17:0:13:0 [/sys/devices/pci0000:97/0000:97:02.0/0000:98:00.0/host17/rport-17:0-22/target17:0:13/17:0:13:0]
7.1.5. If the disk has been added but has not been automatically detected by the system, force it to load:
# rescan-scsi-bus.sh -a
or
# for host in $(ls -1d /sys/class/scsi_host/*); do echo "- - -" > ${host}/scan; done
7.1.6. Install "device-mapper-multipath":
# yum install -y device-mapper-multipath
7.1.7. Enable the multipath configuration:
# mpathconf --enable
7.1.8. Display the multipath configuration:
# mpathconf multipath is enabled find_multipaths is yes user_friendly_names is enabled default property blacklist is enabled enable_foreign is set (no foreign multipath devices will be shown) dm_multipath module is loaded multipathd is not running
7.1.9. Optionally edit the multipath configuration:
# vi /etc/multipath.conf
7.1.10. Enable and start the "multipathd" service:
# systemctl enable multipathd; systemctl start multipathd
7.1.11. Verify that the multipath device "mpatha" is available:
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 1.8T 0 disk ├─sda1 8:1 0 256M 0 part /boot/efi ├─sda2 8:2 0 1G 0 part /boot └─sda3 8:3 0 68.8G 0 part ├─vg00-root_lv 253:0 0 3G 0 lvm / ├─vg00-swap_lv 253:1 0 4G 0 lvm [SWAP] ├─vg00-usr_lv 253:2 0 10G 0 lvm /usr ├─vg00-home_lv 253:3 0 3G 0 lvm /home ├─vg00-var_lv 253:4 0 5G 0 lvm /var ├─vg00-tmp_lv 253:5 0 5G 0 lvm /tmp └─vg00-opt_lv 253:6 0 2G 0 lvm /opt sdb 8:16 0 1T 0 disk └─mpatha 253:13 0 1T 0 mpath sdc 8:32 0 1T 0 disk └─mpatha 253:13 0 1T 0 mpath sdd 8:48 0 1T 0 disk └─mpatha 253:13 0 1T 0 mpath sde 8:64 0 1T 0 disk └─mpatha 253:13 0 1T 0 mpath # multipath -ll mpatha (360050764008101956000000000000239) dm-13 IBM,2145 size=1.0T features='1 queue_if_no_path' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 15:0:13:0 sdc 8:32 active ready running | `- 17:0:12:0 sdd 8:48 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 15:0:12:0 sdb 8:16 active ready running `- 17:0:13:0 sde 8:64 active ready running
7.2. Creating a file system on the multipath device
7.2.1. Create a primary partition of type "Linux LVM" on the multipath device (or continue directly with the "pvcreate" command below and use the entire disk):
# fdisk /dev/mapper/mpatha
Welcome to fdisk (util-linux 2.32.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xaa4e142f.
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-2147483647, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-2147483647, default 2147483647): +600G
Created a new partition 1 of type 'Linux' and of size 600 GiB.
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): L
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 84 OS/2 hidden or c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx
5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data
6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility
8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt
9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi ea Rufus alignment
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD eb BeOS fs
f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ee GPT
10 OPUS 55 EZ-Drive a7 NeXTSTEP ef EFI (FAT-12/16/
11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f0 Linux/PA-RISC b
12 Compaq diagnost 5c Priam Edisk a9 NetBSD f1 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f4 SpeedStor
16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ f2 DOS secondary
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fb VMware VMFS
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fc VMware VMKCORE
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fd Linux raid auto
1c Hidden W95 FAT3 75 PC/IX bc Acronis FAT32 L fe LANstep
1e Hidden W95 FAT1 80 Old Minix be Solaris boot ff BBT
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'.
Command (m for help): p
Disk /dev/mapper/mpatha: 1 TiB, 1099511627776 bytes, 2147483648 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 32768 bytes / 32768 bytes
Disklabel type: dos
Disk identifier: 0xaa4e142f
Device Boot Start End Sectors Size Id Type
/dev/mapper/mpatha-part1 2048 1258293247 1258291200 600G 8e Linux LVM
Command (m for help): w
The partition table has been altered.
Failed to add partition 1 to system: Invalid argument
The kernel still uses the old partitions. The new table will be used at the next reboot.
Syncing disks.
(The error can be ignored. As an alternative use the "parted" command instead.)
7.2.2. Inform the OS of partition table changes:
# partprobe
7.2.3. Verify that a device mapper device for the new partition has been created:
# ls -l /dev/mapper/mpatha* lrwxrwxrwx 1 root root 8 Aug 1 16:21 /dev/mapper/mpatha -> ../dm-13 lrwxrwxrwx 1 root root 8 Aug 1 16:12 /dev/mapper/mpatha1 -> ../dm-14 # fdisk -l /dev/mapper/mpatha Disk /dev/mapper/mpatha: 1 TiB, 1099511627776 bytes, 2147483648 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 32768 bytes / 32768 bytes Disklabel type: dos Disk identifier: 0xaa4e142f Device Boot Start End Sectors Size Id Type /dev/mapper/mpatha1 2048 1258293247 1258291200 600G 8e Linux LVM # lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 1.8T 0 disk ├─sda1 8:1 0 256M 0 part /boot/efi ├─sda2 8:2 0 1G 0 part /boot └─sda3 8:3 0 68.8G 0 part ├─vg00-root_lv 253:0 0 3G 0 lvm / ├─vg00-swap_lv 253:1 0 4G 0 lvm [SWAP] ├─vg00-usr_lv 253:2 0 10G 0 lvm /usr ├─vg00-home_lv 253:3 0 3G 0 lvm /home ├─vg00-var_lv 253:4 0 5G 0 lvm /var ├─vg00-tmp_lv 253:5 0 5G 0 lvm /tmp └─vg00-opt_lv 253:6 0 2G 0 lvm /opt sdb 8:16 0 1T 0 disk ├─sdb1 8:17 0 600G 0 part └─mpatha 253:13 0 1T 0 mpath └─mpatha1 253:14 0 600G 0 part sdc 8:32 0 1T 0 disk ├─sdc1 8:33 0 600G 0 part └─mpatha 253:13 0 1T 0 mpath └─mpatha1 253:14 0 600G 0 part sdd 8:48 0 1T 0 disk ├─sdd1 8:49 0 600G 0 part └─mpatha 253:13 0 1T 0 mpath └─mpatha1 253:14 0 600G 0 part sde 8:64 0 1T 0 disk ├─sde1 8:65 0 600G 0 part └─mpatha 253:13 0 1T 0 mpath └─mpatha1 253:14 0 600G 0 part
7.2.3.1. If not, create a device mapper device for the new partition:
# kpartx -a /dev/mapper/mpatha
7.2.4. Create a physical volume from the partition that will be used within LVM:
# pvcreate /dev/mapper/mpatha1 Physical volume "/dev/mapper/mpatha1" successfully created.
7.2.5. Create a volume group "db_vg" from the physical volume:
# vgcreate db_vg /dev/mapper/mpatha1 Volume group "db_vg" successfully created
7.2.6. Create a 125 GB logical volume "db01_lv" in the volume group:
# lvcreate -n db01_lv -L 125G db_vg Logical volume "db01_lv" created.
7.2.7. Format the logical volume with the XFS file system:
# mkfs.xfs /dev/db_vg/db01_lv
mkfs.xfs: Volume reports stripe unit of 32768 bytes and stripe width of 0, ignoring.
meta-data=/dev/db_vg/db01_lv isize=512 agcount=4, agsize=8192000 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1 bigtime=0 inobtcount=0
data = bsize=4096 blocks=32768000, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=16000, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
7.2.8. Create a mount point for the file system:
# mkdir /db01
7.2.9. Edit /etc/fstab to make the file system available permanently:
# echo '/dev/mapper/db_vg-db01_lv /db01 xfs defaults 0 0' >> /etc/fstab
7.2.10. Update systemd with the new /etc/fstab configuration (RHEL/CentOS 7/8):
# systemctl daemon-reload
7.2.11. Mount the file system:
# mount /db01
7.2.12. Verify that the new file system is mounted:
# df -h /db01 Filesystem Size Used Avail Use% Mounted on /dev/mapper/db_vg-db01_lv 125G 925M 125G 1% /db01
7.3. Extending a file system after resizing the physical storage device (LUN)
7.3.1. If a SCSI disk capacity has been increased and has not been automatically detected by the system, force it to load:
# rescan-scsi-bus.sh
or
# for disk in $(ls -1d /sys/class/scsi_disk/*); do echo "1" > ${disk}/device/rescan; done
7.3.2. Resize the multipath device:
# multipathd resize map /dev/mapper/mpatha
7.3.3. Display information about the increased multipath device:
# lsblk | grep -w mpatha
7.3.4. Extend the file system (including the corresponding partition, physical volume and logical volume) similarly as described from 4.2.2.3.
7.4. Removing a file system including the multipath device
7.4.1. Umount the "/db01" file system:
# umount /db01
7.4.2. Remove the mount point:
# rmdir /db01
7.4.3. Deactivate the logical volume:
# lvchange -a n db_vg/db01_lv
7.4.4. Remove the logical volume including the file system:
# lvremove db_vg/db01_lv Logical volume "db01_lv" successfully removed
7.4.5. Remove the entry from /etc/fstab:
# sed -i '/db01_lv/d' /etc/fstab
7.4.6. Update systemd with the new /etc/fstab configuration (RHEL/CentOS 7/8):
# systemctl daemon-reload
7.4.7. Remove the physical volume from the volume group (the physical volume must be empty):
# vgreduce db_vg /dev/mapper/mpatha1 Removed "/dev/mapper/mpatha1" from volume group "db_vg"
7.4.8. Deactivate the volume group:
# vgchange -a n db_vg
7.4.9. Remove the volume group:
# vgremove db_vg Volume group "db_vg" successfully removed
7.4.10. Remove the physical volume from LVM:
# pvremove /dev/mapper/mpatha1 Labels on physical volume "/dev/mapper/mpatha1" successfully wiped.
7.4.11. Remove the unused multipath device map:
# multipath -f mpatha
7.4.12. Remove all paths to the multipath device:
# echo "sdb
sdc
sdd
sde" | while read dev; do echo 1 > /sys/block/${dev}/device/delete; done
8. Creating an encrypted file system
8.1. Encrypt the partition using LUKS and enter a passphrase (key):
# cryptsetup luksFormat /dev/vdb1 WARNING! ======== This will overwrite data on /dev/vdb1 irrevocably. Are you sure? (Type uppercase yes): YES Enter passphrase for /dev/vdb1: Verify passphrase:
8.2. Decrypt the encrypted partition and maps it to the logical device-mapper device "secret":
# cryptsetup luksOpen /dev/vdb1 secret Enter passphrase for /dev/vdb1:
8.3. Optionally verify that the mapped device exists:
# dmsetup ls --target crypt secret (253, 6)
8.4. Optionally add another passphrase (key) to the encrypted partition:
# cryptsetup luksAddKey /dev/vdb1 Enter any existing passphrase: Enter new passphrase for key slot: Verify passphrase:
8.5. Optionally verify that the key(s) exist(s) for the encrypted partition:
# cryptsetup luksDump /dev/vdb1
LUKS header information for /dev/vdb1
Version: 1
Cipher name: aes
Cipher mode: xts-plain64
Hash spec: sha256
Payload offset: 4096
MK bits: 256
MK digest: 7a 89 b0 52 d3 0f 94 6c e0 e0 ea 86 ea 06 1c aa 40 66 7d e4
MK salt: e6 82 0f fa 9c 1c 8e 76 0e a6 44 d0 76 1e 6e b6
7e e3 33 8a 2b f4 ad 16 02 b7 e3 ed 5f 84 84 41
MK iterations: 28845
UUID: aad9f193-a734-45e6-815a-a9029b03a020
Key Slot 0: ENABLED
Iterations: 463150
Salt: 3f fc 35 b6 09 ff 2d 4f 56 df 1a 59 e3 64 f1 28
44 4e 1f 5d 08 24 ad a8 27 fc b0 5a a4 e4 da 24
Key material offset: 8
AF stripes: 4000
Key Slot 1: ENABLED
Iterations: 482768
Salt: 21 4f 42 9e 87 d9 4f 03 3a 67 69 a1 e7 e7 66 82
01 7e 1c 8d 27 71 2c 6b be d5 f5 de 85 ed 80 63
Key material offset: 264
AF stripes: 4000
Key Slot 2: DISABLED
Key Slot 3: DISABLED
Key Slot 4: DISABLED
Key Slot 5: DISABLED
Key Slot 6: DISABLED
Key Slot 7: DISABLED
(The corresponding number of key slots is occupied.)
8.6. Format the partition with the XFS file system:
# mkfs.xfs /dev/mapper/secret
meta-data=/dev/mapper/secret isize=512 agcount=4, agsize=610240 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=2440960, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
8.7. Create a mount point for the file system:
# mkdir /secret
8.8. Mount the file system:
# mount /dev/mapper/secret /secret
8.9. Optionally create a test file:
# touch /secret/test # ls -l /secret/test -rw-r--r--. 1 root root 0 Nov 3 12:34 /secret/test
8.10. When done, unmount the file system and unmap the encrypted partition:
# umount /secret # cryptsetup luksClose secret
9. Creating a network file system (NFS)
9.1. Configuring NFS server
9.1.1. Install the NFS server/client package (if not installed already):
[root@nfsserver ~]# yum -y install nfs-utils
9.1.2. Enable and start the NFS services:
[root@nfsserver ~]# systemctl enable --now nfs-server rpcbind Created symlink from /etc/systemd/system/multi-user.target.wants/nfs-server.service to /usr/lib/systemd/system/nfs-server.service.
9.1.3. Create the directory "/nfsshare" to be shared by NFS clients:
[root@nfsserver ~]# mkdir /nfsshare
9.1.4. Create some data in the directory (for the example purpose):
[root@nfsserver ~]# echo "$(hostname)" > /nfsshare/test
9.1.5. Optionally associate the IP address of the NFS client with the hostname:
[root@nfsserver ~]# echo "192.168.124.254 nfsclient" >> /etc/hosts
9.1.6. Modify the /etc/exports file to export the "/nfsshare" directory to the NFS client, allowing read and write access with root privileges:
[root@nfsserver ~]# echo '/nfsshare nfsclient(rw,no_root_squash)' >>/etc/exports
(The NFS clients can be specified as hostnames, IP addresses or networks, separated by spaces.)
9.1.7. Reload the /etc/exports configuration file:
[root@nfsserver ~]# exportfs -rv exporting nfsclient:/nfsshare
9.1.8. Configure the firewall to allow access to the NFS service:
[root@nfsserver ~]# firewall-cmd --add-service={nfs,rpc-bind,mountd} --permanent
success
[root@nfsserver ~]# firewall-cmd --reload
success
9.1.9. Optionally list the NFS services and their versions:
[root@nfsserver ~]# rpcinfo -p
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100005 1 udp 20048 mountd
100005 1 tcp 20048 mountd
100005 2 udp 20048 mountd
100005 2 tcp 20048 mountd
100024 1 udp 40636 status
100005 3 udp 20048 mountd
100024 1 tcp 55863 status
100005 3 tcp 20048 mountd
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100227 3 tcp 2049 nfs_acl
100003 3 udp 2049 nfs
100003 4 udp 2049 nfs
100227 3 udp 2049 nfs_acl
100021 1 udp 52141 nlockmgr
100021 3 udp 52141 nlockmgr
100021 4 udp 52141 nlockmgr
100021 1 tcp 38894 nlockmgr
100021 3 tcp 38894 nlockmgr
100021 4 tcp 38894 nlockmgr
9.2. Configuring NFS client
9.2.1. Install the NFS server/client package (if not installed already):
[root@nfsclient ~]# yum -y install nfs-utils
9.2.2. Create the mount point "/mnt/nfsshare":
[root@nfsclient ~]# mkdir /mnt/nfsshare
9.2.3. Optionally associate the IP address of the NFS server with the hostname:
[root@nfsclient ~]# echo "192.168.124.80 nfsserver" >> /etc/hosts
9.2.4. Edit the /etc/fstab to mount the exported "/nfsshare" on the "/mnt/nfsshare" permanently:
[root@nfsclient ~]# echo 'nfsserver:/nfsshare /mnt/nfsshare nfs defaults 0 0' >> /etc/fstab
9.2.5. Mount the exported "/nfsshare":
[root@nfsclient ~]# mount -a
9.2.6. Verify that the "/mnt/nfsshare" is writable by root on the NFS client:
[root@nfsclient ~]# echo "$(hostname)" >> /mnt/nfsshare/test [root@nfsclient ~]# cat /mnt/nfsshare/test nfsserver nfsclient
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