Well today I have to search files with *.php and with *.html .
How to do that ?
Solution is :
find ./ Â \( -name "*.php" -o -name "*.html" Â \)
January 26, 2012
search files with multiple patterns in linux
autoscaling with amazon ec2 and elb
Creating an auto scaled system using an Amazon load balancer is an interesting task that I did recently.
Here are the list of commands that I used to setup from the command line :
as-create-launch-config ec2elbconfig --image-id ami-xxxxx --instance-type m1.large --key key_name
Also if you don’t have already setup credentials you may append
-I amazonid -S secretkey
Do not forget to add –key because after the instance is up you won’t be able to log on it.
Next command is:
as-create-auto-scaling-group MyAutoScalingGroup --launch-configuration ec2elbconfig --availability-zones us-east-1c --min-size 2 --max-size 6 --load-balancers MyLoadBalancer
Where : MyLoadBalancer – is the name of your ELB ( loading balancer ) from amazon
Nex we create two policy rules, one for adding server and one for remover:
[root@server]# as-put-scaling-policy HighCpuPolicy --auto-scaling-group MyAutoScalingGroup --adjustment=1 --type ChangeInCapacity --cooldown 300
arn:aws:autoscaling:us-east-1:xxx:scalingPolicy:xxx-xx-xx-xx-xxxxx:autoScalingGroupName/MyAutoScalingGroup:policyName/HighCpuPolicy
[root@server]# as-put-scaling-policy LowCpuPolicy --auto-scaling-group MyAutoScalingGroup --adjustment=-1 --type ChangeInCapacity --cooldown 300
arn:aws:autoscaling:us-east-1:xxx:scalingPolicy:xxx-xx-xx-xx-xxxxx:autoScalingGroupName/MyAutoScalingGroup:policyName/LowCpuPolicy
Here is important to remember the output.
After this we must create two monitor rules that will scale our balancer, so will need two more rules:
mon-put-metric-alarm HighCpuAlarm --comparison-operator GreaterThanThreshold --evaluation-periods 4 --metric-name CPUUtilization --namespace "AWS/EC2" --period 60 --statistic Average --threshold 30 --alarm-actions arn:aws:autoscaling:us-east-1:xxx:scalingPolicy:xxx-xx-xx-xx-xxxxx:autoScalingGroupName/MyAutoScalingGroup:policyName/HighCpuPolicy --dimensions "AutoScalingGroupName=MyAutoScalingGroup"
and
mon-put-metric-alarm LowCpuAlarm --comparison-operator LessThanThreshold --evaluation-periods 4 --metric-name CPUUtilization --namespace "AWS/EC2" --period 60 --statistic Average --threshold 20 --alarm-actions arn:aws:autoscaling:us-east-1:xxx:scalingPolicy:xxx-xx-xx-xx-xxxxx:autoScalingGroupName/MyAutoScalingGroup:policyName/LowCpuPolicy --dimensions "AutoScalingGroupName=MyAutoScalingGroup"
After this you will have allways 2 instance up, and if the load go up then 30% more then 4 minutes the system will go up with one more server, if the load go bellow 20% more then 4 minutes will remove one server from load balancer.
If you need to remove this you must delete rules from bottom to top using bellow commands with name of your rules.
mon-delete-alarms
as-delete-policy
as-delete-auto-scaling-group
as-delete-launch-config
January 13, 2012
RAID10 ephemeral storage on AWS EC2
If you’re thinking of doing Radi10Â Â on the ephemeral storage disks attached to an Ec2Â instance, this post is for you. Well first of all you have to chose a instance with 4 drives.
You may chose m1.xlarge or c1.xlarge  or cc2.8xlarge . This are only instances with 4 drives. On other instances you may chose to make Raid0, witch in some case is good also.
Well first of all you have to boot your instance, after this please check if you have mounted one of them ( in some cases only one is mounted as ephemeral0 )
You have to umount that drive.
After that fdisk on oll of them and make one drive with full size ( in this manner we will make a raid10 ) with all space.
To see your drivers just run
ls -1 /dev/sd*
and you will see something like :
/dev/sda1
/dev/sdb
/dev/sdc
/dev/sdd
/dev/sde
What I want to do is to make sdb, sdc, sdd, sde one raid10
I’ll just create a single partition on each one. Using fdisk, I choose the fd (Linux raid auto) partition type and create partitions using the entire disk on each one. When I’m done, each drive looks like this:
fdisk -l /dev/sdb
Disk /dev/sdb: 450.9 GB, 450934865920 bytes
255 heads, 63 sectors/track, 54823 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc696d4f6
Device Boot Start End Blocks Id System
/dev/sdb1 1 54823 440365716 fd Linux raid autodetect
Now I create the raid
mdadm  -v --create /dev/md0 --level=raid10 --raid-devices=4 /dev/xvdb1 /dev/xvdc1 /dev/xvdd1 /dev/xvde1
This is taking some time, so to verify if the construction of raid is ready run
 watch cat /proc/mdstat
When is ready you have to see something like this
Personalities : [raid10]
md127 : active raid10 xvdc1[1] xvdb1[0] xvdd1[2] xvde1[3]
880729088 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
unused devices: <none>
Ok now we have to create a new partition. Just fdisk /dev/md0 Â create your partition.
fdisk /dev/md0Â
mkfs -t ext4 /dev/md0p1
mkdir /mnt/raidd
mount  /dev/md0p1  /mnt/raidd
After you done this, reboot your server . After the server is up and running, on amazon it appear that they will be rename . So md0p1 will be someting lik md127
You may run
grep md /var/log/dmesg
and you will see something like this
[ 0.436792] md: bind<xvde1>
[ 0.444720] md: bind<xvdd1>
[ 0.526356] md: bind<xvdb1>
[ 0.543458] md: bind<xvdc1>
[ 0.547763] md: raid10 personality registered for level 10
[ 0.548234] md/raid10:md127: active with 4 out of 4 devices
[ 0.548311] md127: detected capacity change from 0 to 901866586112
After this you may add to fstab bellow line:
/dev/md127p1 /mnt/raidd auto defaults,comment=cloudconfig 0 2
Now if you run
mount /mnt/raiddÂ
you shuld have raid mounted
df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda1 9.9G 2.4G 7.0G 26% /
tmpfs 7.4G 0 7.4G 0% /dev/shm
/dev/md127p1 827G 6.7G 779G 1% /mnt/raidd
