2011/1/24 Andreas Dilger <adilger@xxxxxxxxx> > > On 2011-01-23, at 20:46, Robin Dong wrote: > > Having a view of blocks usage of block group descriptors, block/inode bitmaps, inode table, block pointer blocks, extents .etc, can help users in many cases, > > 1) Make estimation on how many memory might be occupied as buffer cache or page cache. > > 2) For some specific workload, is a file system is well formatted for block usage, e.g. whether there are never-be-used blocks allocated for inode table. > > 3) If there is a chance to allocated meta data from non-seek-cost device like SSD as a meta-data device, first of all user should know how many meta data blocks are allocated/used on the file system. > > > > Therefore a tool to collect block usage information and display in a clear view is necessary. This patch is a first effort to provide such a tool which is called e2view so far. > > Much of this information is available via "dumpe2fs -h" already, though perhaps a more clear summary of the total block usage could be added to dumpe2fs. > > Instead, perhaps a better summary for the e2freefrag tool would be good, which also prints out a histogram of free blocks in the filesystem. > > I'd personally rather avoid adding another tool to print information like this, and just make one of the existing tools print it. Thank you for your suggestions. In my opinion, the main purpose of e2freefrag tool is to print FREE blocks information, not used block. Is it a better choice that I add a flag "-m" for dumpe2fs to display the usage of meta data ? -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
