Software Raid Question(install new disk with mdraid)

[pnix]

I have 2 harddisks(hda,hdc) and built them as Software RAID array(mdraid) when install FC3.

Now I found that hdc is bad and need to replace. I'm not sure, Can I just replace it with a brandnew disk then mdraid will partition and copy everything for me? or I need to prepare partition table first before replace the old one.

another question is how can I know that mdraid will copy from hda to new hdc(that what I want) or it will copy from hdc to hda.

below is my /proc/mdstat

[root@ora10g ~]# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 hda2[0]
30716160 blocks [2/1] [U_]

md2 : active raid1 hda3[0]
30716160 blocks [2/1] [U_]

md3 : active raid1 hda4[0]
1124480 blocks [2/1] [U_]

md0 : active raid1 hda1[0]
15358016 blocks [2/1] [U_]

unused devices: <none>
[root@ora10g ~]#

[bryancole]

Here's what you do (however I've not tried this exact procedure, so you might want to wait for a more authorative advice!)

1) First remove your failed device from each array: "mdadm Manage --remove md1 /dev/hdc2" etc.
2) Then replace your disk (unless it's hotswappable hardware you'll need to power down)
3) Recreate the partitions on the new hdc (raid partitions in this case), using 'parted' or fdisk etc.
4) Add the partitions to the raid arrays: "mdadm Manage --add md1 /dev/hdc2"

The new array-components should start building in the background. You may need to leave things overnight to complete. see the man-page for mdadm for more details.

You need to set up the partitions to match your existing disk (making raid-partitions as appropriate); you have to do this manually. You then

[pnix]

Thanks bryancole, sorry for late reply. I'm too busy this week and just test your advice today and it work.