ok i see! So when there are like 3/3/4 that means double index blocks?? How many extents can a single extent index hold in a block? ________________________________________ From: Andreas Dilger [adilger@xxxxxxxxx] Sent: Tuesday, June 26, 2012 11:40 AM To: Nelson, John R Cc: linux-ext4@xxxxxxxxxxxxxxx Subject: Re: Extent Depth Histogram Fsck On 2012-06-26, at 8:34 AM, Nelson, John R wrote: > What does the extent depth histogram mean? Is it a measure of something? > > like mine is > > > Extent depth histogram: 36010/81 This means that of all the extent-mapped files in the filesystem, 36010 files have an extent tree of depth 0 (i.e. they fit inside the inode) 81 files have an extent tree of depth 1 (i.e. there is a single index block) Typically, files larger than 4 * 128MB = 512MB need an index block, but if the maximum-sized extents cannot be allocated then an index block will be needed for smaller files. Only if you have very large files (> 40GB), or a very fragmented free space would you need more than a single level of index blocks. Cheers, Andreas -- 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
