Merge pull request #421 from QuinnyPig/grammar

Fixup EFS Wording

README.md

@@ -283,7 +283,7 @@ Many services within AWS can at least be compared with Google Cloud offerings or
 | PaaS                          | Elastic Beanstalk                                                            | App Engine                   | App Engine      | Web Apps                           | Heroku, AppFog, OpenShift | Meteor, AppScale, Cloud Foundry, Convox                    |
 | Serverless, microservices     | Lambda, API Gateway                                                          | Functions                    |                 | Function Apps                      | PubNub Blocks, Auth0 Webtask      | Kong, Tyk                                                  |
 | Container, cluster manager    | ECS                                                                          | Container Engine, Kubernetes | Borg or Omega   | Container Service                  |                                   | Kubernetes, Mesos, Aurora                                  |
-| File storage                  | S3                                                                           | Cloud Storage                | GFS             | Storage Account                    |                                   | Swift, HDFS                                                |
+| Object storage                  | S3                                                                           | Cloud Storage                | GFS             | Storage Account                    |                                   | Swift, HDFS                                                |
 | Block storage                 | EBS                                                                          | Persistent Disk              |                 | Storage Account                    | DigitalOcean Volumes              | NFS                                                        |
 | SQL datastore                 | RDS                                                                          | Cloud SQL                    |                 | SQL Database                       |                                   | MySQL, PostgreSQL                                          |
 | Sharded RDBMS                 |                                                                              | Cloud Spanner                | F1, Spanner     |                                    |                                   | Crate.io, CockroachDB                                      |
@@ -757,7 +757,7 @@ EC2
 
 ### EC2 Tips
 
--	🔹**Picking regions:** When you first set up, consider which [regions](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html#concepts-available-regions) you want to use first. Many people in North America just automatically set up in the us-east-1 (N. Virginia) region, which is the default, but it’s worth considering if this is best up front. You'll want to evaluate service availibility (some services [are not available in all regions](https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services/)), costing (baseline costs also [vary by region](https://aws.amazon.com/ec2/pricing/) by up to 10-30% (generally lowest in us-east-1 for comparison purposes)), and compliance (various countries have differing regulations with regard to data privacy, for example).
+-	🔹**Picking regions:** When you first set up, consider which [regions](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html#concepts-available-regions) you want to use first. Many people in North America just automatically set up in the us-east-1 (N. Virginia) region, which is the default, but it’s worth considering if this is best up front. You'll want to evaluate service availability (some services [are not available in all regions](https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services/)), costing (baseline costs also [vary by region](https://aws.amazon.com/ec2/pricing/) by up to 10-30% (generally lowest in us-east-1 for comparison purposes)), and compliance (various countries have differing regulations with regard to data privacy, for example).
 -	**Instance types:** EC2 instances come in many types, corresponding to the capabilities of the virtual machine in CPU architecture and speed, RAM, disk sizes and types (SSD or magnetic), and network bandwidth.
 	-	Selecting instance types is complex since there are so many types. Additionally, there are different generations, released [over the years](https://aws.amazon.com/blogs/aws/ec2-instance-history/).
 	-	🔹Use the list at [**ec2instances.info**](http://www.ec2instances.info/) to review costs and features. [Amazon’s own list](https://aws.amazon.com/ec2/instance-types/) of instance types is hard to use, and doesn’t list features and price together, which makes it doubly difficult.
@@ -935,10 +935,10 @@ EFS
 -	EFS is designed to be used as a shared network drive and it can automatically scale up to petabytes of stored data and thousands of instances attached to it.
 -	It’s presented as an [NFSv4.1](https://en.wikipedia.org/wiki/Network_File_System#NFSv4) server, so any compatible NFS client can mount it.
 -	EFS can offer [higher throughput](http://docs.aws.amazon.com/efs/latest/ug/performance.html) (multiple gigabytes per second) and better durability and availability than EBS (see [the comparison table](#storage-durability-availability-and-price)), but with higher latency.
--	EFS is priced based on the amount of data stored and it costs [much more than EBS](#storage-durability-availability-and-price), about three times as much compared to general purpose gp2 EBS volumes.
+-	EFS is priced based on the volume of data stored, and costs [much more than EBS](#storage-durability-availability-and-price); it's in the ballpark of three times as much compared to general purpose gp2 EBS volumes.
--	⏱ [Performance](http://docs.aws.amazon.com/efs/latest/ug/performance.html) depends on the amount of data stored on it, which also determines the price:
+-	⏱ [Performance](http://docs.aws.amazon.com/efs/latest/ug/performance.html) is dependent on the volume of data stored, as is the price:
 	-	Like EBS, EFS uses a credit based system. Credits are earned at a rate of 50 KiB/s per GiB of storage and consumed in bursts during reading/writing files or metadata. Unlike EBS, operations on metadata (file size, owner, date, etc.) also consume credits. The [BurstCreditBalance metric](http://docs.aws.amazon.com/efs/latest/ug/monitoring-cloudwatch.html#efs-metrics) in CloudWatch should be monitored to make sure the file system doesn't run out of credits.
-	-	Throughput capacity during bursts is also dependant on size. Under 1 TiB, throughput can go up to 100 MiB/s. Above that, 100 MiB/s is added for each stored TiB. So a file system storing 5 TiB would be able to burst at a rate of 500 MiB/s. Maximum throughput per EC2 instance is 250 MiB/s.
+	-	Throughput capacity during bursts is also dependent on size. Under 1 TiB, throughput can go up to 100 MiB/s. Above that, 100 MiB/s is added for each stored TiB. For instance, a file system storing 5 TiB would be able to burst at a rate of 500 MiB/s. Maximum throughput per EC2 instance is 250 MiB/s.
 	-	EFS has two performance modes that can only be set when a file system is created. One is "General Purpose", the other is "Max I/O". Max I/O scales higher, but at the cost of higher latency. When in doubt, use General Purpose, which is also the default. If the [PercentIOLimit metric](http://docs.aws.amazon.com/efs/latest/ug/monitoring-cloudwatch.html#efs-metrics) in CloudWatch hovers around 100%, Max I/O is recommended. Changing performance mode means creating a new EFS and migrating data.
 -	High availability is achieved by having [mount targets in different subnets / availability zones](http://docs.aws.amazon.com/efs/latest/ug/images/overview-flow.png).
 
@@ -953,7 +953,7 @@ EFS
 
 	Cons:
 	- Since credits are shared, if one application over-consumes them, it will affect the others.
-	- A compromise is made with regards to [security](http://docs.aws.amazon.com/efs/latest/ug/security-considerations.html). All clients will have to have network access to the drive. Someone with root access on one client instance can mount any directory on the EFS and they have read-write access to all files on the drive, even if they don't have access to the applications hosted on other clients.
+	- A compromise is made with regards to [security](http://docs.aws.amazon.com/efs/latest/ug/security-considerations.html): all clients will have to have network access to the drive. Someone with root access on one client instance can mount any directory on the EFS and they have read-write access to all files on the drive, even if they don't have access to the applications hosted on other clients. There isn't a no-root-squash equivalent for EFS.
 
 ### EFS Gotchas and Limitations
 
@@ -963,7 +963,7 @@ EFS
 -	🔸 An EFS file system can NOT be mounted over VPC peering or VPN, even if the VPN is running on top of Direct Connect.
 -	🔸 Using an EFS volume on Windows is not supported.
 -	⏱ When a file is uploaded to EFS, it can take hours for EFS to update the details for billing and burst credit purposes.
--	🔸⏱  Metadata operations can be costly in terms of burst credit consumption. Recursively traversing a tree containing thousands of files can easily ramp up to tens or even hundreds of megabytes of burst credits being consumed, even if no file is being touched. Commands like ```find``` or ```chown -R``` can have an adverse impact on performace if run periodically.
+-	🔸⏱  Metadata operations can be costly in terms of burst credit consumption. Recursively traversing a tree containing thousands of files can easily ramp up to tens or even hundreds of megabytes of burst credits being consumed, even if no file is being touched. Commands like ```find``` or ```chown -R``` can have an adverse impact on both cost and performance if run regularly.
 
 
 Load Balancers