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AWS Certified SysOps Administrator - Associate Questions and Answers (Dumps and Practice Questions)



Question : HadoopExam Sysadmin has created a launch configuration for Auto Scaling where CloudWatch detailed monitoring is disabled.
Now sysadmin wants to now enable detailed monitoring. How can the user achieve this?
: HadoopExam Sysadmin has created a launch configuration for Auto Scaling where CloudWatch detailed monitoring is disabled.
1. Update the Launch config with CLI to set InstanceMonitoringDisabled = false
2. The user should change the Auto Scaling group from the AWS console to enable detailed monitoring
3. Update the Launch config with CLI to set InstanceMonitoring.Enabled = true
4. Create a new Launch Config with detail monitoring enabled and update the Auto Scaling group


Correct Answer : 4

Explanation: Auto Scaling instances send metrics to Amazon CloudWatch. Instance metrics are the metrics that an individual EC2 instance sends to CloudWatch. Instance metrics are the same
metrics available for any EC2 instance, whether or not it is in an Auto Scaling group.

CloudWatch offers basic or detailed monitoring. Basic monitoring sends aggregated data about each instance to CloudWatch every five minutes. Detailed monitoring offers more frequent
aggregated data by sending data from each instance every minute.
CloudWatch is used to monitor AWS as well as the custom services. To enable detailed instance monitoring for a new Auto Scaling group, the user does not need to take any extra steps.
When the user creates the AutoScaling launch config as the first step for creating an Auto Scaling group, each launch configuration contains a flag named InstanceMonitoring.Enabled.
The default value of this flag is true. When the user has created a launch configuration with InstanceMonitoring.Enabled = false it will involve multiple steps to enable detail
monitoring. The steps are: Create a new Launch config with detailed monitoring enabled Update the Auto Scaling group with a new launch config Enable detail monitoring on each EC2
instance.

To enable detailed instance monitoring for a new Auto Scaling group, you don't need to take any extra steps. One of your first steps when creating an Auto Scaling group is to create
a launch configuration. Each launch configuration contains a flag named InstanceMonitoring.Enabled. The default value of this flag is true, so you don't need to set this flag
manually if you want detailed monitoring.

If you have an Auto Scaling group for which you have explicitly selected basic monitoring, the switch to detailed monitoring involves several steps, especially if you have CloudWatch
alarms configured to scale the group automatically.







Question : It __________ that you read or write to all the blocks on your volume before you use it
: It __________ that you read or write to all the blocks on your volume before you use it
1. is not recommended
2. is recommended
3. is not good for performance



Correct Answer : 2

Explanation: New EBS Volumes always experience a "First Use Penalty" in AWS; means there will be a performance hit on the first write to an unused block on the EBS Volume and will perform
slower than subsequent writes. During this time you can experience spike in volume metrics like service times, I/O latency and then subsequently leading to normalization. It is
observed that 5 to 50 percent reduction in IOPS when you first access the data on a volume. Performance is restored after the data is accessed once. Therefore, it is recommended that
you read or write to all the blocks on your volume before you use it.
$ dd if=/dev/md0 of=/dev/null
In Linux, the above command reads from all blocks on a volume and pre-warms the volume. On Windows, formatting the new EBS volume pre-warms it.
"dd" is not verbose by default so download and use the following script from the github, it shows the status of the pre warming of EBS Volumes






Question : A user is trying to pre-warm a blank EBS volume attached to a Linux instance.
Which of the below mentioned steps should be performed by the user?
: A user is trying to pre-warm a blank EBS volume attached to a Linux instance.
1. There is no need to pre-warm an EBS volume
2. Contact AWS support to pre-warm
3. Unmount the volume before pre-warming
4. Format the device


Correct Answer : 3


Explanation: Pre-Warming Amazon EBS Volumes

When you create any new EBS volume (General Purpose (SSD), Provisioned IOPS (SSD), or Magnetic) or restore a volume from a snapshot, the back-end storage blocks are allocated to you
immediately. However, the first time you access a block of storage, it must be either wiped clean (for new volumes) or instantiated from its snapshot (for restored volumes) before
you can access the block. This preliminary action takes time and can cause a 5 to 50 percent loss of IOPS for your volume the first time each block is accessed. For most
applications, amortizing this cost over the lifetime of the volume is acceptable. Performance is restored after the data is accessed once.

However, you can avoid this performance hit in a production environment by writing to or reading from all of the blocks on your volume before you use it; this process is called
pre-warming. Writing to all of the blocks on a volume is preferred, but that is not an option for volumes that were restored from a snapshot, because that would overwrite the
restored data. For a completely new volume that was created from scratch, you should write to all blocks before using the volume. For a new volume created from a snapshot, you should
read all the blocks that have data before using the volume.

When the user creates a new EBS volume or restores a volume from the snapshot, the back-end storage blocks are immediately allocated to the user EBS. However, the first time when the
user is trying to access a block of the storage, it is recommended to either be wiped from the new volumes or instantiated from the snapshot (for restored volumes. before the user
can access the block. This preliminary action takes time and can cause a 5 to 50 percent loss of IOPS for the volume when the block is accessed for the first time. To avoid this it
is required to pre warm the volume. Pre- warming an EBS volume on a Linux instance requires that the user should unmount the blank device first and then write all the blocks on the
device using a command, such as "dd".

New EBS Volumes always experience a "First Use Penalty" in AWS; means there will be a performance hit on the first write to an unused block on the EBS Volume and will perform slower
than subsequent writes. During this time you can experience spike in volume metrics like service times, I/O latency and then subsequently leading to normalization. It is observed
that 5 to 50 percent reduction in IOPS when you first access the data on a volume. Performance is restored after the data is accessed once. Therefore, it is recommended that you read
or write to all the blocks on your volume before you use it.
$ dd if=/dev/md0 of=/dev/null
In Linux, the above command reads from all blocks on a volume and pre-warms the volume. On Windows, formatting the new EBS volume pre-warms it.
"dd" is not verbose by default so download and use the following script from the github, it shows the status of the pre warming of EBS Volumes



Related Questions

Question : QuickTechie Admin launched an RDS postgreSQL DB with AWS. The user did not specify the maintenance window during creation. The user has
configured RDS to update the DB instance type from micro to large. If the user wants to have it during the maintenance window, what will AWS
do?
 : QuickTechie Admin launched an RDS postgreSQL DB with AWS. The user did not specify the maintenance window during creation. The user has
1. AWS will not allow to update the DB until the maintenance window is configured
2. AWS will select the default maintenance window if the user has not provided it
3. AWS will ask the user to specify the maintenance window during the update
4. It is not possible to change the DB size from micro to large with RDS





Question : Acmeshell Inc's Sysadmin has created a subnet in VPC and launched an EC instance within it.Admin has not selected the option to assign
the IP address while launching the instance. The user has 3 elastic IPs and is trying to assign one of the Elastic IPs to the VPC
instance from the console. The console does not show any instance in the IP assignment screen. What is a possible reason that
the instance is unavailable in the assigned IP console?
 : Acmeshell Inc's Sysadmin has created a subnet in VPC and launched an EC instance within it.Admin has not selected the option to assign
1. The IP address may be attached to one of the instances
2. The IP address belongs to a different zone than the subnet zone

3. The user has not created an internet gateway

4. The IP addresses belong to EC2 Classic; so they cannot be assigned to VPC



Question : John is an Administrator at Acmeshell Inc and has launched multiple EC instances for the purpose of development and testing in the same region.
Now he wants to find the separate cost for the production and development instances. How can the user find the cost distribution?
 : John is an Administrator at Acmeshell Inc and has launched multiple EC instances for the purpose of development and testing in the same region.
1. The user should download the activity report of the EC2 services as it has the instance ID wise data
2. It is not possible to get the AWS cost usage data of single region instances separately
3. The user should use Cost Distribution Metadata and AWS detailed billing
4. The user should use Cost Allocation Tags and AWS billing reports


Question : A user has created a VPC with CIDR .../ using VPC Wizard. The user has created a public CIDR (.../.
and a VPN only subnet CIDR (20.0.1.0/24. along with the hardware VPN access to connect to the user's data centre.
Which of the below mentioned components is not present when the VPC is setup with the wizard?
 : A user has created a VPC with CIDR .../ using VPC Wizard. The user has created a public CIDR (.../.
1. Main route table attached with a VPN only subnet
2. A NAT instance configured to allow the VPN subnet instances to connect with the internet
3. Custom route table attached with a public subnet
4. An internet gateway for a public subnet



Question : A user has created a VPC with the public subnet. The user has created a security group for that VPC.
Which of the below mentioned statements is true when a security group is created?

 : A user has created a VPC with the public subnet. The user has created a security group for that VPC.
1. It can connect to the AWS services, such as S3 and RDS by default
2. It will have all the inbound traffic by default
3. It will have all the outbound traffic by default
4. It will by default allow traffic to the internet gateway






Question : A user has setup an Auto Scaling group. The group has failed to launch a single instance for more than hours. What will happen to Auto
Scaling in this condition?
 : A user has setup an Auto Scaling group. The group has failed to launch a single instance for more than hours. What will happen to Auto
1. Auto Scaling will keep trying to launch the instance for 72 hours
2. Auto Scaling will suspend the scaling process
3. Auto Scaling will start an instance in a separate region
4. The Auto Scaling group will be terminated automatically