First at all, I need to say sorry if my english is not perfect. I speak spanish. I post here because gentoo-user-es it's middle dead, and it's a great chance to practice my english :) Now, the problem.

I'm going to get a new PC with a disc SSD 120GB and another HDD of 1TB. But in a coming future, I want to add 2 or more disks SSD.

Mi idea now, is:

    Disk HHD: /dev/sda

/dev/sda1 26GB

/dev/sda2 90GB

/dev/sda3 904GB

    Disk SSD: /dev/sdb

/dev/sdb1 26GB

/dev/sdb2 90GB

/dev/sdb3 4GB

And use /dev/sdb3 as swap. (I will add more with another SSD in future)

/dev/sda3 mounted in /home/user/data (to save data unused)

And a RAID 1 with:

md0: sda1+sdb1    /

md1: sda2+sdb2    /home

(sda1 and sda2 will be made with the flag: write-mostly. This is useful for disks slower).

In a future, I'm going to add more SSD's on this RAID. My idea is the fastest I/O.

Now. My problem/question is:

Following the gentoo's doc, it says I need to put the flag --metadata=0.9 on the RAID. My question is ¿This will make get off the performance?.

I only found this document. This says the difference, but nothing about performance and advantages/disadvantages.

Another question is, ¿GRUB2 still unsupporting metadata 1.2?

In case that metadata get off performance, and GRUB2 doesn't support this. ¿Anyone knows how can I fix this to use metadata 1.2?

I don't partitioned more, because I saw this unnecessary. I just need to separate /home in case I need to format the system. But if I need to separate /boot to make it work, I don't have problems doing that.

¿Somebody have any ideas to make it work?

Thank you all. Bytes! ;)