使用iOS 5.0.1 beta版设备测试iOS应用(Test iOS app with device of iOS 5.0.1 beta version)

 在进一步调查的基础上，结论已被逆转 
 
 虽然几乎所有驱动器都使用512字节逻辑扇区，但现代分区表使用LBA地址，而LBA单元大小是设备的逻辑扇区大小，现在可能高达4096字节。 
 
 最后，我将关于单元大小的问题发布到主要的GNU parted（分区编辑器）邮件列表，并收到了此响应 。 特别： 
 
 “LBA始终指的是驱动器的块大小。因此它可能是512或4096或其他值，具体取决于驱动器报告的内容。” 
 
 先前的答案版本不正确：[[分区表（在MBR中，否则）是指512字节块/逻辑扇区。 例如，参见https://en.wikipedia.org/wiki/Master_boot_record#PTE。]] 
 
 背景资料 
 
 磁盘物理磁盘扇区大小的报告似乎从根本上通过ATA-8规范中的命令完成，特别是“IDENTIFY DEVICE”命令。 兼容性问题（最常讨论）是I / O操作的对齐。 显然大多数驱动器处理512字节对齐，但性能损失，尽管有一些驱动器被宣称为“4k native”或“4kn”，根本不支持512字节对齐的I / O. 通常，具有物理4k扇区的驱动器使用所谓的“高级格式”，这可以帮助您搜索是否需要更多信息。 
 
 本文https://linuxconfig.org/linux-wd-ears-advanced-format有一些相对清晰的讨论，特别是如果您是Linux用户。 值得一提的是，在Linux上，“parted -l”命令报告物理和逻辑扇区大小，parted也知道如何为高级格式设备正确对齐分区。 
 
 此外，您可能会发现这篇文章http://www.seagate.com/tech-insights/advanced-format-4k-sector-hard-drives-master-ti/有关此问题的信息和安慰。 

Conclusion has been reversed based on further investigation
 
Although almost all drives use 512-byte logical sectors, modern partition tables use LBA addresses, and LBA unit size is the logical sector size of the device, which today may be as great as 4096 bytes.
 
In the end I posted the question about unit size to the main GNU parted (partition editor) mailing list and have received this response. Specifically:
 
"LBA always refers to the drive's block size. So it may be 512 or 4096 or some other value, depending on what the drive reports."
 
Incorrect previous answer version: [[Partition tables (in the MBR and otherwise) refer to 512 byte blocks / logical sectors. See for example https://en.wikipedia.org/wiki/Master_boot_record#PTE.]]
 
Background information
 
Reporting of disk physical disk sector sizes seems to be fundamentally done through commands in the ATA-8 specification, specifically the "IDENTIFY DEVICE" command. Compatibility issues (most often discussed) are alignment of I/O operations. Apparently most drives handle 512 byte alignment, but with performance penalties, though there are some drives advertised as "4k native" or "4kn" that do not support 512 byte aligned I/O at all. In general, drives with physical 4k sectors use what is called "Advanced Format", which may help you search if you want more info.
 
This article https://linuxconfig.org/linux-wd-ears-advanced-format has some relatively clear discussion, especially if you are a Linux user. For what it's worth, on Linux the "parted -l" command reports physical and logical sector size, and parted also knows how to align partitions appropriately for Advanced Format devices.
 
Also, you might find this article http://www.seagate.com/tech-insights/advanced-format-4k-sector-hard-drives-master-ti/ informative and reassuring on the issue.