AWS ebs documentation change
Summary
Restructured documentation about EBS physical sector size advertisement conditions. Added detailed tables showing instance type support, operating system requirements, and NVMe driver dependencies. Clarified version requirements for 4-KiB sector support.
Security assessment
The changes clarify technical requirements for sector size advertisement but contain no references to security vulnerabilities, patches, or exploits. While NVMe driver version requirements were adjusted (changed from 1.5.1 to 1.4.1), there's no explicit mention of security fixes or vulnerabilities addressed by these versions. The documentation update focuses on operational compatibility rather than security controls.
Diff
diff --git a/ebs/latest/userguide/volume_constraints.md b/ebs/latest/userguide/volume_constraints.md index d5facf199..c21ba3193 100644 --- a//ebs/latest/userguide/volume_constraints.md +++ b//ebs/latest/userguide/volume_constraints.md @@ -101 +101 @@ Data storage on a modern hard drive is managed through _logical block addressing -Amazon EBS advertises either 512-byte or 4,096-byte (4 KiB) physical sectors to the operating system. Amazon EBS advertises 4-KiB physical sectors only if the Amazon EC2 instance type, operating system, and the AWS NVMe driver supports it. If either the instance type, operating system, or AWS NVMe driver does not support 4-KiB physical sectors, Amazon EBS advertises 512-byte physical sectors instead. +Amazon EBS advertises either 512-byte or 4,096-byte (4 KiB) physical sectors to the operating system, depending on the following factors: @@ -103 +103 @@ Amazon EBS advertises either 512-byte or 4,096-byte (4 KiB) physical sectors to -###### Amazon EC2 instance type support + 1. The Amazon EC2 instance type @@ -105 +105 @@ Amazon EBS advertises either 512-byte or 4,096-byte (4 KiB) physical sectors to -The following table shows the sector sizes that Amazon EBS advertises for the different Amazon EC2 instance types. + 2. The operating system @@ -107,3 +107 @@ The following table shows the sector sizes that Amazon EBS advertises for the di -Advertised physical sector size | Instance types ----|--- -512 byte | All Xen-based instances and the following Nitro-based instances: + 3. The NVMe driver version @@ -111,5 +108,0 @@ Advertised physical sector size | Instance types - * General purpose: A1 | M5 | M5a | M5ad | M5d | M5dn | M5n | M5zn | M6g | M6gd | Mac1 | Mac2 | T3 | T3a | T4g - * Compute optimized: C5 | C5a | C5ad | C5d | C5n | C6g | C6gd - * Memory optimized: R5 | R5a | R5ad | R5d | R5dn | R5n | R6g | R6gd | U-12tb1 | U-18tb1 | U-24tb1 | U-3tb1 | U-6tb1 | U-9tb1 | X2gd | X2iezn | Z1d - * Storage optimized: D3 | D3en | I3en - * Accelerated computing: Dl1 | G4ad | G4dn | G5 | G5g | Inf1 | P3dn | P4d | P4de | VT1 @@ -118 +110,0 @@ Advertised physical sector size | Instance types -4 KiB | All other Nitro-based instances @@ -120 +112 @@ Advertised physical sector size | Instance types -###### Operating system support +Amazon EBS advertises 4-KiB physical sectors only if all factors support it. If any one of these do not support 4-KiB physical sectors, Amazon EBS advertises 512-byte physical sectors. @@ -122 +114,3 @@ Advertised physical sector size | Instance types -The following table shows the sector sizes that Amazon EBS advertises for some common operating systems. +###### Amazon EC2 instance type support + +The following table shows the sector sizes that Amazon EBS advertises for the different Amazon EC2 instance types. @@ -124 +118,5 @@ The following table shows the sector sizes that Amazon EBS advertises for some c -###### Note +Instance type | Linux | Windows +---|---|--- +All Xen-based instance types | Amazon EBS always advertises 512-byte physical sectors +A1 | C5 | C5a | C5ad | C5d | C5n | C6g | C6gd | DL1 | D3 | D3en | G4ad | G4dn | G5 | G5g | I3 | I3en | Inf1 | M5 | M5a | M5ad | M5d | M5dn | M5n | M5zn | M6g | M6gd | P3dn | P4d | P4de | R5 | R5a | R5ad | R5d | R5dn | R5n | R6g | R6gd | T3 | T3a | T4g | U-12tb1 | U-18tb1 | U-24tb1 | U-3tb1 | U-6tb1 | U-9tb1 | X2gd | X2iezn | VT1 | Z1d | Amazon EBS always advertises 512-byte physical sectors | Amazon EBS advertises 512-byte or 4-KiB physical sectors 1 +All other Nitro-based instances | Amazon EBS advertises 512-byte or 4-KiB physical sectors 1 @@ -126 +124 @@ The following table shows the sector sizes that Amazon EBS advertises for some c -This is not an exhaustive list. We recommend that you verify the physical sector size advertised by Amazon EBS in your operating system. +1 Depends on the operating system support. See the following section. @@ -128 +126,5 @@ This is not an exhaustive list. We recommend that you verify the physical sector -Advertised physical sector size | Operating systems +###### Operating system support + +The following table provides example operating systems and the corresponding physical sector sizes advertised by Amazon EBS. This is **not an exhaustive list**. We recommend that you verify the physical sector size advertised by Amazon EBS in your operating system. + +Operating system | Advertised physical sector size @@ -130 +131,0 @@ Advertised physical sector size | Operating systems -512 byte | @@ -135,2 +136 @@ Advertised physical sector size | Operating systems - * Windows 7 and earlier - * Windows Server 2008 and earlier + * Windows 7/Windows Server 2008 and earlier @@ -138,2 +138 @@ Advertised physical sector size | Operating systems - -4 KiB | +| 512 byte @@ -144,4 +143 @@ Advertised physical sector size | Operating systems - * Windows 8 and later - * Windows Server 2012 and later - - + * Windows 8/Windows Server 2012 and later 1 @@ -149 +145 @@ Advertised physical sector size | Operating systems -###### AWS NVMe driver support +| 4 KiB @@ -151 +147 @@ Advertised physical sector size | Operating systems -Amazon EBS advertises 4 KiB physical sectors with AWS NVMe driver version 1.5.1 and later. Always ensure that you are using the latest version of the [AWS NVMe driver](./nvme-ebs-volumes.html). +1 For Windows workloads, ensure that you are using the latest version of the [AWS NVMe drivers](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/aws-nvme-drivers.html). Amazon EBS advertises 4-KiB physical sectors with AWS NVMe driver version 1.4.1 and later. @@ -155 +151 @@ Amazon EBS advertises 4 KiB physical sectors with AWS NVMe driver version 1.5.1 -The industry default size for logical data blocks is currently 4 KiB. Because certain workloads benefit from a smaller or larger block size, file systems support non-default block sizes that can be specified during formatting. Scenarios in which non-default block sizes should be used (such as optimizations) are outside the scope of this documentation, but the choice of block size has consequences for the storage capacity of the volume. The following table shows theoretical storage capacity as a function of block size. However, keep in mind that the EBS-imposed limit on volume size (64 TiB for io2 Block Express) is currently equal to the maximum size enabled by 16-KiB data blocks. +The industry default size for logical data blocks is currently 4 KiB. Because certain workloads benefit from a smaller or larger block size, file systems support non-default block sizes that can be specified during formatting. Scenarios in which non-default block sizes should be used (such as optimizations) are outside the scope of this topic, but the choice of block size has consequences for the storage capacity of the volume. The following table shows theoretical storage capacity as a function of block size. However, note that the EBS-imposed limit on volume size (64 TiB for io2 Block Express) is currently equal to the maximum size enabled by 16-KiB data blocks.