mount Soft RAID when restart system
In the morning, I rebooted my computer, and found soft raid 0 made yesterday had been unavailable.Even I tried the steps like yesterday doing, but the RAID still could not be rebuild.
Later,More tell me using the following command to remount the RAID:
# mdadm -A /dev/md0 /dev/hdb /dev/hdc
and then check the /proc/mdstat, yes, not only the RAID was found but also, all the date on the RAID are still here!
RAID has two forms, striping and partity.In fact,RAID 0 was not really RAID because it isn’t redundant. RAID has good write and read performance. There are two important parameters: Strip, and chunk size. Strip means the whole array’s transfer rate per second, which is always used by hardware controllers. Chunk size,belong to Linux kernel, is the single disk’s rate.
RAID1 is mirroing, good read performance nearly twice of the single one, but not good at writing performance for writing data to two disks at time.RAID 2,RAID3 are useless, and RAID 4 just like RAID 5,which has one dedicated disk to save paritition information.