一种基于DCT的磁盘阵列错误恢复算法

DCT Based Algorithm of Image Recovery for Disk Array

磁盘阵列可以提高磁盘存储系统的容量和数据吞吐量 ,而且具有容错能力 ,可以精确重建出错磁盘上的数据 ,但需要增加大量的磁盘访问开销 ,因而在恢复错误期间会影响存储系统的有效吞吐量 .本文针对静止、活动图像压缩算法的特点 ,提出了一种客户端的近似图像错误恢复算法 .该算法将图像分成若干子图存放在磁盘阵列的不同磁盘上 ,在单个磁盘失效时 ,利用DCT块之间的相关性近似恢复图像 ,从而不增加存储系统的开销 .

The disk array can enhance the capacity and throughput of disk storage system, which can tolerate single disk failure and accurately reconstruct lost data. But the reconstruction may reduce the throughput in the reconstruction period because of the spending of increased disk access. An approximate image reconstruction algorithm at client is proposed according to the image compression properties, which divides image into a few subimages and stores them on different disks of disk array. The relativity of DCT blocks can be used to approximately reconstruct damaged images without increasing disk access.