Constraints

KSAL has requirements on the processor model and EC algorithm configuration.

It has the following constraints:

• KSAL can be used only on servers powered by Kunpeng 920 processors.
• The EC algorithm supports only K+1, K+2, K+3, K+4 (2 ≤ K ≤ 25), and 28+3 configurations.
• The EC algorithm supports 64-byte and 4,096-byte encoding and decoding granularities.
• The ceph-ksal-ec-plugin.patch file supports only the 2+2, 4+2, 6+2, 12+3, and 20+3 configurations.
  

  • K in K+1, K+2, K+3, and K+4 (2 ≤ K ≤ 25) indicates the number of data blocks in the EC algorithm, and the number following K indicates the number of parity blocks generated based on these data blocks. For example, the 4+2 configuration indicates that two parity blocks are generated based on four data blocks. This configuration provides a maximum fault tolerance of two blocks, enabling the restoration of the original data using any four of the remaining blocks.
  • The default permission on the KSAL dynamic library is 755 (-rwxr-xr-x), and that on the header file is 644 (-rw-r--r--). You are advised to assign minimal permissions (for example, 550) to the files after installing KSAL.