How can I specify erasure patterns when erasing disk blocks?
擦除磁盘块时如何指定擦除模式？
Later, the RM will update the actual disk blocks corresponding to the changed data.
之后，RM将根据所更改的数据更新实际的磁盘块。
In Listing 2, the first line shows the total number of disk blocks (52) used by the listed files.
在清单2中，第一行显示所列文件使用的磁盘块的总数(52)。
Filesystem blocks are typically a few kilobytes in size, whereas disk blocks are normally 512 bytes.
磁盘文件系统的块大小通常是几KB，然而磁盘块大小通常是512字节。
You can view the current usage of disk blocks: which blocks free, which blocks are occupied by which files.
可以查看当前磁盘块的使用情况：哪些块空闲，哪些块被哪些文件占用。
Late paging space allocation causes paging disk blocks not to be allocated until its corresponding pages in RAM are touched.
晚分页空间分配策略会直到RAM中的页面被修改时才分配相应的分页磁盘块。
This functionality improves the chances that sequential disk blocks are allocated, because the total number needed will be known.
这样所需磁盘空间总数就一目了然，因此这个功能提高了分配连续磁盘块的可能性。
Standard on many Linux distributions, vmstat provides three forms of CPU load, generalized disk blocks in and out, and the capability for monitoring many other system functions.
vmstat是很多Linux发行版的标准配置，它提供了三种形式的CPU负载，一般磁盘块出入以及监视很多其他系统功能的能力。
Because these blocks are contiguous on the disk, there's better read and write performance for them.
由于这些块在磁盘上是连续的，其读取和写入的性能就会更好。
Instead of a map to the original data, there are now new blocks with data, consuming disk space in the file system.
没有对原始数据的映射，现在只有新的数据块在消耗文件系统中的磁盘空间。
If the source is modified, the original contents of the blocks are copied to the disk space area of the snapshot file system.
如果修改了源文件系统，那么数据块的原始内容将复制到快照文件系统的磁盘空间区域。
The filesystem driver updated the appropriate metadata, but didn't have time to flush the data from its caches to the new blocks on disk.
文件系统驱动程序更新适当的元数据，但是没有时间将其缓存中的数据刷新到磁盘的新块中。
Not only is it impossible to write multiple data blocks to disk simultaneously, but writing every data block to disk when any part of it changes would be bad for system performance.
不仅不可能同时将多个数据块写入磁盘，而且每当进行修改时马上将每个数据块写入磁盘，也对系统性能有不利影响。
This performance optimization delays the allocation of physical blocks on the disk until they are to be flushed to the disk.
这种性能优化延迟磁盘上的物理块的分配，直到块被刷入到磁盘时才进行分配。
The search index sat on a small number of disk drives enclosed within Lego-like blocks.
那时候搜索索引就运行在象乐高玩具一样的方块围住的磁盘驱动器里面。
The key to this optimization is that by delaying the allocation of physical blocks until they need to be written to the disk, more blocks are present to allocate and write in contiguous blocks.
这种优化的关键是延迟物理块的分配，直到需要在磁盘上写这些物理块时才对其进行分配并写到相邻的块。
When a transaction is applied to the filesystem proper, the data blocks are written to disk first.
当事务应用于适当的文件系统时，数据块首先被写到磁盘。
Listing 6 shows how to determine how many blocks were read from disk versus those from memory.
清单6显示了如何确定有多少块是从磁盘中读取的，以及有多少块是从内存中读取的。
Ideally, requests for these blocks should come from memory instead of disk.
理想情况下，对于这些块的请求应该来自于内存，而不是来自于磁盘。
After all, complete blocks contain modified data but may also contain unmodified (already on disk) data as well.
毕竟，包含已修改数据的完整块中还可能包含未修改的(已经在磁盘上)数据。
Ext4 fixes this with a block allocator that allocates multiple blocks at a time, likely contiguous on disk.
ext4使用块分配器修复了这个问题，它能够在磁盘上一次分配多个块。
Like XFS and Reiser4, ext4fs includes delayed allocation to allocate blocks on the disk only when needed (which reduces fragmentation).
像XFS和Reiser 4一样，ext4fs还支持在必要时采取延时分配方式分配块(这样可以减少磁盘碎片)。
Rather than rely on allocation lists (metadata to map blocks on a disk to a given file), Ceph USES an interesting alternative.
Ceph使用一个有趣的备选，而不是依赖分配列表(将磁盘上的块映射到指定文件的元数据)。
The actual disk arms must find the correct cylinder, the control needs to access the correct blocks, and the disk heads have to wait while the blocks rotate to them.
实际的磁臂必须找到正确的柱面，控制部分需要访问正确的块，并且磁头必须等到这些块旋转到磁头下面。
It provides the basis for dealing with the on-disk file system, as it defines the file system's managing parameters (for example, total number of blocks, free blocks, root index node).
它是处理磁盘上的文件系统的基础，因为它定义文件系统的管理参数(例如，块的总数、空闲块和根索引节点)。
It clones only the used blocks on the hard disk.
它只克隆硬盘中被使用的块。
Partial solar eclipses happen when the moon blocks only part of the sun's disk, as seen from Earth, casting regions of the planet in shadow.
当月亮遮住部分太阳时，日偏食发生了，就像从地球上看到的一样，使得地球上的部分地区笼罩在阴影中。
Like ReiserFS, XFS USES a logical journal; that is, it does not journal literal filesystem blocks like ext3, and instead USES an efficient on-disk format to log metadata changes.
象reiserfs一样，XFS使用逻辑日志；即，它不象ext3那样将文字文件系统块记录到日志，而是使用一种高效的磁盘格式来记录元数据的变动。
These many is caused by a hardware problem, such as damaged, some blocks in memory or CPU overheating, or hard disk is bad, or light aging, read out data has a problem, and so on.
这些情况很多是由于硬件问题造成的，如内存中某些区块损坏，或者CPU过热，或者硬盘存在坏道，或者光驱老化，读取出来的数据有问题等等。
A 512 byte area of disk storage. Each disk sector contains two 256 byte disk data blocks.
一个512字节的磁盘存储区，每个磁盘扇区含有两个256字节的磁盘数据块。
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