RAID1
DAID1 referred to as mirror storage, which data redundancy through mirroring disk data, the principle of mutual backup data is generated on a pair of independent disks.
Advantages: RAID 1 advantage is that any one disk fails, the data stored will not be lost. When the original data is busy, data can be read directly from the mirrored copy thus read faster performance.
Disadvantages: the actual capacity of the hard disk can be used in this mode is relatively small, only one-half the capacity of the two drives.
Composition Condition: two identical size hard disk.
Raid1 configuration conditions also require two disks, but here we take into account the actual production, we give it on the basis of two discs plus a spare disk, in case of need. Before creating raid so we need to add two disks, and its partition and file system type of modification. Since the operation here as two drives, operating on only one disc presentation. Before raid1 create the same need to look at whether to create a raid mdadm tool has been installed, such as when operating raid0 same.
At this time in front of the preparatory work has been completed, we can begin to create raid1 rolled.
Each time the operation is complete you must remember to check out our operating results.
raid1 created, we need to remember to format and mount to normal use.
Since we give it with a spare disk, so also remember to validate whether the normal use. Here we first write the contents of md1 in.
Because we spare disk is to replace it in time when a work disks accidental damage, so damage to disk here we simulate a work in two, it can verify that after damage does not affect the normal data read our and spare sdf1 also the first time to enter the working mode.
These are the Linux system to create a RAID 1.