A striped volume in Linux, also known as RAID 0, is a way of combining multiple physical disks into a single logical storage unit. Data is “striped” across the disks in blocks, so that each disk stores a portion of the data. This can provide increased performance and capacity, as well as redundancy, depending on the RAID level used. However, it also increases the risk of data loss if one of the disks fails, as all data on the striped volume will be lost.
To create a striped logical volume in Linux, you can use the “lvcreate” command from the Logical Volume Manager (LVM). Here are the general steps to follow:
- Identify the physical volumes that you want to use for the striped logical volume. These can be individual disk partitions or entire physical disks that are already part of a volume group.
- At least two physical volumes are necessary to create striped volume, here we are using /dev/sdb and /dev/sdc to create a striped volume.
[root@techielinux ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 17G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 16G 0 part
├─centos-root 253:0 0 14.3G 0 lvm /
└─centos-swap 253:1 0 1.7G 0 lvm [SWAP]
sdb 8:16 0 1G 0 disk
sdc 8:32 0 1G 0 disk
sr0 11:0 1 1024M 0 rom
[root@techielinux ~]#- Create a physical volume with Below command.
[root@techielinux ~]# pvcreate /dev/sdb /dev/sdc
Physical volume "/dev/sdb" successfully created.
Physical volume "/dev/sdc" successfully created.
[root@techielinux ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <16.00g 4.00m
/dev/sdb lvm2 --- 1.00g 1.00g
/dev/sdc lvm2 --- 1.00g 1.00g
[root@techielinux ~]#- Create a volume group using physical volumes (/dev/sdb /dev/sdc )
[root@techielinux ~]# vgcreate strip_vg /dev/sdb /dev/sdc
Volume group "strip_vg" successfully created
[root@techielinux ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- <16.00g 4.00m
strip_vg 2 0 0 wz--n- 1.99g 1.99g
[root@techielinux ~]#
- Now Create a Striped Logical Volume using below command
[root@techielinux ~]# lvcreate -L 1G -i 2 -I 256k -n strip_lv strip_vg
Logical volume "strip_lv" created.
[root@techielinux ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- 14.29g
swap centos -wi-ao---- <1.70g
strip_lv strip_vg -wi-a----- 1.00g
-i2 means the number of stripes
-I 256k means the stripe size in KB
-L<size> means the size of logical volume
-n strip_lv means the name of logical volume
strip_vg is the name of volume group.
- Format the Logical Volume with a Filesystem of your choice. For Example, to Format it with the XFS Filesystem.
[root@techielinux ~]# mkfs.xfs /dev/mapper/strip_vg-strip_lv
meta-data=/dev/mapper/strip_vg-strip_lv isize=512 agcount=8, agsize=32704 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=261632, imaxpct=25
= sunit=64 swidth=128 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=1728, version=2
= sectsz=512 sunit=64 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@techielinux ~]#- Create a mount point for the logical volume, for example:
[root@techielinux ~]# mkdir /strip- Mount the logical volume to the mount point you created:
[root@techielinux ~]# mount /dev/mapper/strip_vg-strip_lv /strip
- You can also create an entry in /etc/fstab file to mount the raid array automatically at boot time.
[root@techielinux ~]# vi /etc/fstab
[root@techielinux ~]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Fri Nov 18 11:40:01 2022
#
# 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
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=4b5c6d5d-008c-4852-97f1-56815a02488b /boot xfs defaults 0 0
/dev/mapper/centos-swap swap swap defaults 0 0
/dev/mapper/strip_vg-strip_lv /strip xfs defaults 0 0
[root@techielinux ~]# df -ThP /strip
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/strip_vg-strip_lv xfs 1016M 33M 983M 4% /strip
[root@techielinux ~]#- Verify the logical volume Type.
[root@techielinux ~]# lvs --segments
LV VG Attr #Str Type SSize
root centos -wi-ao---- 1 linear 14.29g
swap centos -wi-ao---- 1 linear <1.70g
strip_lv strip_vg -wi-ao---- 2 striped 1.00g
[root@techielinux ~]#
Note: This is a general process for creating a striped logical volume, the specific commands and options may vary depending on your Linux distribution and the specific RAID level you’re using. Also make sure LVM is installed in your machine and you have sufficient space in the volume group to create a new logical volume.