Reducing fsck time for ext2 file systems
Reducing fsck time for ext2 file systems
复制标题
减少 ext2 文件系统的 fsck 时间
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Theodore Ts’o
中科院分区：
文献类型：
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作者：
Val Henson;Zach Brown;Theodore Ts’o
Ext2 快速、简单、强大并且使用起来很有趣。然而，它已经失宠的一个主要原因是：如果 ext2 文件系统没有完全卸载，例如在内核崩溃或断电的情况下，则必须使用 fsck 进行修复，这需要几分钟或几小时才能完成，在此期间文件系统不可用。在本文中，我们描述了一些减少 ext2 文件系统上的平均 fsck 时间的技术。首先，我们通过添加一个文件系统范围的脏位来指示文件系统在崩溃时是否正在被主动修改，从而避免在某些情况下运行 fsck。经过此更改的 ext2 的性能接近普通 ext2，并且比 ext3 快很多。其次，我们提出了一种称为链接写入的技术，它使用相关写入和脏 inode 列表来允许通过仅修复脏 in-ode 并避免完整文件系统检查来恢复活动文件系统。
Ext2 is fast, simple, robust, and fun to hack on. However, it has fallen out of favor for one major reason: if an ext2 file system is not cleanly unmounted, such as in the event of kernel crash or power loss, it must be repaired using fsck, which takes minutes or hours to complete, during which time the file system is unavailable. In this paper, we describe some techniques for reducing the average fsck time on ext2 file systems. First, we avoid running fsck in some cases by adding a file system wide dirty bit indicating whether the file system was being actively modified at the time it crashed. The performance of ext2 with this change is close to that of plain ext2, and quite a bit faster than ext3. Second, we propose a technique called linked writes which uses dependent writes and a list of dirty inodes to allow recovery of an active file system by only repairing the dirty in-odes and avoiding a full file system check.