How to create LV with Visual LVM : mirror/RAID 1 - manage LVM with Visual LVM, from 0 to ∞ (14)
Section 4 : The Logical Volume operations
Author : weLees
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Section 4.1.3 Create Logical Volume - Mirror/RAID 1
The Mirror/RAID 1 is one of the standard types of RAID. It consists of two or more storage sections of the same size present in the host device (that is, the Physical Volume), and no, they are not divided as stripes. The component of Mirror volume can be treat as a volume for all data written in will be wrote to all component of Mirror. The mirror/RAID 1 type has the highest level of security. Any one component damaged will not affect work. But it needs to waste half its capacity to store (backup) all the data.
The disk 0 and disk 1 are copies of each other.
To create mirror volume, you need to select at least two Physical Volumes which belongs to the same Volume Group, the selected Physical Volume will be remove when you select a Physical Volume in other Volume Group. The mirror format bar will be enabled after 2+ Physical Volume selected.
select at least 2 Physical Volumes for create mirror volume
The rules for volume size and all parameters have been discussed in the previous chapter. If you are not clear, please refer to How to create stripe/RAID 0 volume
As a complicated type of RAID, the components of mirror volume must has the same size too. So the rule of volume size changing via mouse dragging is the same with stripe type. The only difference is : the size of mirror type volume is not the sum of all components, but the size of a single component.
The restriction of volume size setting
And you can press Advance... button to change default settings of Logical Volume.
Usually user need not to change the default advance settings of Logical Volume.
There is only one advanced setting for the mirror type that differs from the stripe type:
Region size : To determine how much data to copy to the co-component(s) in one synchronization operation.
Advanced settings of Logical Volume
When all settings finished, press Done button on creating Logical Volume wizard to perform operation.
After operation finished, Visual LVM shows follow dialog to inform user that Logical Volume has been created.
Logical Volume created