raid setup on providerservice

gistfile1.txt

#get data about current RAID
#1 block = 1kb 
cat /proc/mdstat
mdadm --detail --scan


#to get to the real fstab
mount /dev/md1 /tmp/1
vi /tmp/1/etc/fstab #find out the md # of the partition that u want to reformat
mdadm --detail /dev/md6 #more details about that partition, especially the /dev/sda6 + /dev/sdb6 info


mdadm --stop /dev/md6 #STOP ALL MD partitions (gotten from --scan)

fdisk /dev/sda -> delete partition 6 -> create 2 new partitions -> set type to "fd" -> write
fdisk /dev/sdb -> delete partition 6 -> create 2 new partitions -> set type to "fd" -> write

#create new raid partitions
 mdadm --create --auto=yes --verbose /dev/md6 --level=1 --raid-devices=2 /dev/sda6 /dev/sdb6
mdadm --create --auto=yes --verbose /dev/md7 --level=1 --raid-devices=2 /dev/sdb7 /dev/sda7

watch cat /proc/mdstat # to check status
#start all raid devices
mdadm --assemble --scan --auto=yes # will follow /etc/mdadm/mdadm.conf . so add additional entries there

#setup xfs
mkfs.xfs -d sunit=512,swidth=1024 /dev/md6
mkfs.xfs -d sunit=512,swidth=1024 /dev/md7

#correct the filesystem config of the system
mount /dev/md1 /tmp/1

# add to /etc/fstab
/dev/md6     /home     xfs     noattr2,noatime,nodiratime,osyncisdsync,logbsize=256k,logbufs=8,sunit=512,swidth=1024    0    2
/dev/md7     /data     xfs     noatime,sunit=512,swidth=1024    0    2


mdadm --detail --scan > /tmp/1/etc/mdadm/mdadm.conf
#unmount the mounted fs
umount /tmp/1

#reboot

#install 3.0 kernel for improvements to XFS, etc.
apt-get install linux-image-3.0.0-19-server

### Tune XFS
#xfs information
xfs_info /dev/md6

#benchmark
sysbench --test=fileio --file-num=1 --file-total-size=1GB --file-test-mode=rndwr --max-requests=0 --file-fsync-freq=0 --file-extra-flags=direct --num-threads=8 --max-time=30 run

#turn off write caching
hdparm -W0 /dev/sdb
hdparm -W0 /dev/sda

#check for fragmentation
xfs_db -c frag -r /dev/md6
#defrag
xfs_fsr -v -t 600

hdparm.conf

#/etc/hdparm.conf

command_line {
       hdparm -W0 /dev/sda
       hdparm -W0 /dev/sdb
}

postgresql

#/etc/sysctl.conf

#for postgresql
kernel.shmall=2097152
kernel.shmmax=1134217728

# General gigabit tuning:
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = "4096 87380 16777216"
net.ipv4.tcp_wmem = "4096 65536 16777216"

#timewait sockets
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1

#firewall conntrack
net.ipv4.netfilter.ip_conntrack_max = 1048576
net.nf_conntrack_max = 1048576

# this gives the kernel more memory for tcp
# which you need with many (100k+) open socket connections
net.ipv4.tcp_mem = "50576   64768   98152"
#SACKs are an optimization to TCP which in normal scenarios improves considerably performance. 
#In Gigabit networks with no traffic competition these have the opposite effect. 
#To improve performance they should be turned off by: 
net.ipv4.tcp_sack = 0 

# Decrease the time default value for tcp_fin_timeout connection
net.ipv4.tcp_fin_timeout = 15
# Decrease the time default value for tcp_keepalive_time connection
net.ipv4.tcp_keepalive_time = 1800
# Turn off the tcp_window_scaling
# Helps in some cases. You can play with it
#net.ipv4.tcp_window_scaling = 0

#increased backlog (default: 1000)
#if you are under DDoS you can get them up to 65535
net.core.netdev_max_backlog = 4096
net.core.somaxconn = 4096

#Timestamp adds additional 12 bytes to header, so disable it
net.ipv4.tcp_timestamps = 0

#portrange for outgoing connections
#(increase the ephemeral port range)
net.ipv4.ip_local_port_range="1024 65535"

# Unicorn advised tunning
net.ipv4.tcp_orphan_retries = 1
net.ipv4.tcp_max_orphans = 8192

postgresql.conf

#for 8GB RAM

shared_buffers = 1GB
maintenance_work_mem = 200MB 
wal_buffers = 16MB
effective_cache_size = 4GB