Free Trial

Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.


  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

17. Access Control Lists > ACL Implementation Limits

ACL Implementation Limits

The various file-system implementations impose limits on the number of entries in an ACL:

  • On ext2, ext3, and ext4, the total number of ACLs on a file is governed by the requirement that the bytes in all of the names and values of a file’s extended attributes must be contained in a single logical disk block (Extended Attribute Implementation Details). Each ACL entry requires 8 bytes, so that the maximum number of ACL entries for a file is somewhat less (because of some overhead for the name of the extended attribute for the ACL) than one-eighth of the block size. Thus, a 4096-byte block size allows for a maximum of around 500 ACL entries. (Kernels before 2.6.11 imposed an arbitrary limitation of 32 entries for ACLs on ext2 and ext3.)


  

You are currently reading a PREVIEW of this book.

                                                                                                                    

Get instant access to over $1 million worth of books and videos.

  

Start a Free Trial


  
  • Safari Books Online
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint