堆内存设置原理JVM堆内存分为2块：Permanent Space 和 Heap Space。Permanent 即 持久代（Permanent Generation），主要存放的是Java类定义信息，与垃圾收集器要收集的Java对象关系不大。Heap = { Old + NEW = {Eden, from, to} }，Old 即 年老代（Old Generation

2.1．Xattr介绍官方描述：Extended attributes extend the basic attributesof files and directories in the file system. They are stored as name:data pairsassociated with file system objects (files, directorie