ITPub博客

Why does my system swaps the data instead of freeing cache and buffer memory?[@more@]The kernel uses heuristics to guess which pages of memory are likely to be needed in the near future, and tries to keep those pages in memory, regardless of whether they belong to processes or kernel caches. It is normal for the kernel to swap out process memory even when there is plenty of cache memory that could be easily freed. The kernel heuristics can be tuned by changing the vm.swappiness parameter of

The CPU’s Translation Lookaside Buffer (TLB) is a small cache used for storing virtual-tophysical mapping information. By using the TLB, a translation can be performed without referencing the in-memory page table entry that maps the virtual address. However, to keeptranslations as fast as possible, the TLB is usually small. It is not uncommon for large memory applications to exceed the mapping capacity of the TLB.[@more@]在2.6的kernel里对这个值 的评价是这样的：This memory management feature is

做一个恢复测试，又碰上了，插个小别针记录下。[@more@]比如，如果需预期目的是要从/Test1 (逻辑link) ---> /u01/data/test1 (实体目录)这样的模式这样写就好了：ln -s /u01/data/test1 /Test1注意，这里的/Test1目录是不需要事先建立好的，link后会自动建立，另外就是顺序啦，记得ln -s语法顺序是前实体目录，后逻辑link就好。