iSCSI/NFS on LVM on RAID5 (Software RAID) howto guide, CentOS 5.3

This is just a quid blog to show howto, cos I found there are not much on-line tutorial cover this in a easy way.

And of course, as I keep it simple, it only cover basic stuffs. Please feel free to comment and add on better approach.

## RAID ##
===============================
Links:
 http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch26_:_Linux_Software_RAID

= Create Partition with 'fdisk'
to create partition (with 'n')
modify the partition's label to RAID (with 't', and code is fd)
then 'w' to write the partition
repeat until the disks is done
do a 'partprobe' to make sure it's written and take effect
do 'fdisk -l' to make sure the partition tables is correct

= Assign disk to raid
mdadm -C -v /dev/md0 -l5 -n3 /dev/hdb1 /dev/hdc1 /dev/hdd1
    # l5 => RAID 5, n3 => a RAID set of 3 disks
cat /proc/mdstat  # make sure RAID is created. it will also show if it's sync-ing or recoverying
mdadm -D -s -v   # Double check. or 'mdadm -D -s -V /dev/md0 


## LVM ##
===============================
Links: 
 http://www.howtoforge.com/linux_lvm_p3

= Create Physical Volume(PV), Volume Group(VG) and Logical Volume(LV)
pvcreate /dev/md0   # assign "/dev/md0" as an PV
pvdisplay    # make sure they're all set
vgcreate vg-raid /dev/md0  # create VG group "lvm-raid" 
vgdisplay    # Show the Volume Group status
lvcreate -n xStorage -L 40G vg-raid # Create a LV as xStorage, 40G from vg-raid
lvdisplay    # Show Logical Volume status
ls /dev/vg-raid/xStorage  # The created LV should be here.. 
mkfs.ext3 /dev/vg-raid/xStorage # format the LV to be used
mount /dev/vg-raid/xStorage /mnt # lets test if we could mount it. :-) 
df -h    # You should see it in your mounted list

## iSCSI ##
===============================
Links: 
 http://www.cyberciti.biz/tips/howto-setup-linux-iscsi-target-sanwith-tgt.html

= Installation
yum -y install scsi-target-utils iscsi-initiator-utils
chkconfig iscsid on
chkconfig iscsi on
chkconfig tgtd on
chkconfig --list | grep iscsi
chkconfig --list | grep tdtd
/etc/init.d/iscsi restart
/etc/init.d/tgtd restart
/etc/init.d/iscsid restart

= Configuring iSCSI Target (iSCSI Server)
tgt-setup-lun  -d /dev/vg-raid/xStorage  -n xStore 192.168.1.4 # create lun only accept client with IP 192.168.1.4
   #*** NOTE: You can only setup lun with a device, not partition!! ***#
tgtadm --lld iscsi --op show --mode target    # Show alll luns
iscsiadm --mode discovery --type sendtargets --portal 192.168.1.4 # List lun from the server
Change iptables:
 iptables -I RH-Firewall-1-INPUT -p tcp -m tcp --dport 3260 -j ACCEPT # Open the port to all NIC
 iptables-save > /etc/sysconfig/iptables     # Save the updated rules to iptables configuration file
 
= Configuring iSCSI Initiator (iSCSI Client)
iscsiadm -m discovery --type sendtargets --portal 192.168.1.4 # Check if the iSCSI Target is accessable 
iscsiadm -m node -T iqn.2001-04.com.NesSAN-xStore -l   # -l to login to target, -u to logout
          # add '--portal 192.168.1.4:3260' for specifid server 
ll /dev/sd*        # The new disk should be now there.
mount /dev/sdc /mnt       # Lets mount it..
df -h
touch `hostname`-`date +%Y%m%d-%H%M%S`    # Test if it's writable and if it's sync over the network


## NFS ##
===============================
Links: 
 http://www.cyberciti.biz/tips/howto-setup-linux-iscsi-target-sanwith-tgt.html


echo '
# Local Mount Name  # Client Access List
/mnt           192.168.1.0/24(rw,no_root_squash,sync)
' >> /etc/exports

exportfs -a
/etc/init.d/nfs restart  # Restart nfs mount

Disable root ssh...

I've been wanted to run my own testing server. Finally, I set it up today. Sign up an account in DynDNS.com. Set up some setting in my wifi router so it can update my dynamic IP regular. After some configuration, that's it! It was like 10mins work. ssh works, tunneling works, sftp works.. nice!

But of course, having a server that would let people connect to it is quite dangerous. Especially, it's my home network. I was lucky enough to see Professor Raymond Chan online.. oh.. i'm not gonna miss the chance, right? SO, I asked him the best way to setup the iptables. So, I drop all incoming, except ssh port. I'm gonna open port 80 so I can play apache server a bit. ^^ And on my router side, I set more security options in my router. I may setup a VPN or something, just incase if someone hack into my server. They can't access some of my Windows machine.

Then, did some testing from different network... from cdot machines, from my iPhone.. cool.. it worked! But connecting from iPhone needs some trick. The trick is have to make sure the iPhone has an IP first. It's kinda weired...

When I was testing the login, I almost forgot to test if I could ssh with root.. oh.. yeah.. gotta disable it. 30second search on net, found the disable root login. I would love to share with any one...

= First, make sure u have root privilege, u can either use "sudo" or "su -".. then...
vi /etc/ssh/sshd_config
= find the following line.. remove "#" and change "yes" to "no"
PermitRootLogin no
= save and test!!

That's it!

At this point, I'm not sure what I'll be testing on it.. Apache, of course.. I may set up a small Beowulf cluster if it's possible. I hope I'll able to run VM in this machine.. but this machine is only like 700mhz AMD CPU with 512 ram.. it'd be really slow to run VM.

Ideally, I should put this server in front of my home network. Set it as a router with strong firewall protection, put my home network be hide it. I don't have a real plan for this yet... Lets see if I have time for it... ^^