SoftwareRAID 10 만들기 (disk 4)
Since I can’t seem to find instructions on how to do this (yet)…
I’m going to create a 4-disk RAID10 array using Linux Software RAID and mdadm. The old way is to create individual RAID1 volumes and then stripe a RAID0 volume over the RAID1 arrays. That requires creating extra /dev/mdN nodes which can be confusing to the admin that follows you.
1) Create the /dev/mdN node for the new RAID10 array. In my case, I already have /dev/md0 to /dev/md4 so I’m going to create /dev/md5 (note that “5” appears twice in the command).
# mknod /dev/md5 b 9 5
2) Use fdisk on the (4) drives, create a single primary partition of type “fd” (Linux raid autodetect). Note that I have *nothing* on these brand new drives, so I don’t care if it wipes out data.
3) Create the mdadm RAID set using 4 devices and a level of RAID10.
# mdadm –create /dev/md5 -v –raid-devices=4 –chunk=32 –level=raid10 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1
Which will result in the following output:
mdadm: layout defaults to n1
mdadm: size set to 732571904K
mdadm: array /dev/md5 started.
# cat /proc/mdstat
Personalities : [raid1] [raid10]
md5 : active raid10 sdf1 sde1 sdd1 sdc1
1465143808 blocks 32K chunks 2 near-copies [4/4] [UUUU]
[>………………..] resync = 0.2% (3058848/1465143808) finish=159.3min speed=152942K/sec
As you can see, we get around 150MB/s from the RAID10 array. The regular RAID1 arrays only have about 75MB/s throughput (same as a single 750GB drive).
A final note. My mdadm.conf file is completely empty on this system. That works well for simple systems, but you’ll want to create a configuration file in more complex setups.