[Gluster-users] Questions about healing

[Gandalf Corvotempesta]

Ciao,
i'm planning a new infrastructure. I have some questions about
healing to better optimize performances in case of brick failure.

Let's assume this environment:

3 supermicro servers, replica 3, with 12 SATA disks each.
each servers has 2 bricks in RAID-6 (software or
hardware, i don't know) made by 6 disks each.

1) in case of a single disk failure, healing would not
happen as RAID is recovering on it's own

2) in case of total brick failure (3 broken disks in a RAID-6),
healing would happen, right ? During the healing, the whole brick
is locked for write? Even if the other 2 servers are working properly?

3) in case of total server failure, healing would happen like on point 2?

I'm asking this because I don't know if using Gluster to store virtual 
machines
disk images or mount a filesystem inside each virtual machine.
In the first case, when healing happen, the whole VM is locked down, right?
If the same brick has multiple VM storage, all VM would be locked.

In the second case, only the healed file is locked. As we host mainly 
webservers
with tons of small files, healing would be almost transparent (heal a 
20kb file
would require a second, not hours)