> So st_blocks on FUSE mount is different from st_blocks on backend for the > same file? Yes. Just a quick example: I create a file with 5 Bytes in size. I theory Gluster should report 8 x 512 Byte blocks, because the underlying XFS uses a 4K block size. Instead, it reports the minimum count of blocks the file size would fit in: client> echo test > /gluster/tmp/test.txt client> stat /gluster/tmp/test.txt File: `/gluster/tmp/test.txt' Size: 5 Blocks: 1 IO Block: 131072 regular file Device: 14h/20d Inode: 12072747239032953097 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2013-11-26 12:09:22.960828776 +0100 Modify: 2013-11-26 12:09:22.964828962 +0100 Change: 2013-11-26 12:09:22.964828962 +0100 Birth: - gluster> stat /bricks/0/tmp/test.txt File: `/bricks/0/tmp/test.txt' Size: 5 Blocks: 8 IO Block: 4096 regular file Device: ca03h/51715d Inode: 859069733 Links: 2 Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2013-11-26 12:09:22.957683891 +0100 Modify: 2013-11-26 12:09:22.961684089 +0100 Change: 2013-11-26 12:09:22.961684089 +0100 Birth: - > > On Nov 25, 2013 8:50 AM, "Maik Kulbe" <info at linux-web-development.de> > wrote: > > From man (2) stat: > > blksize_t st_blksize; /* blocksize for file system I/O */ > blkcnt_t ?st_blocks; ?/* number of 512B blocks allocated */ > > The 128K ?you are seeing is "st_blksize" which is the recommended I/O > transfer size. The number of consumed blocks is always reported as 512 > byte blocks. The actual block size with which storage allocation > happens > depends on the backend filesystem. > > This is what was confusing me. On the file systems one of our > programmers tested the latter one it was always showing the blocks > allocated. So if you had a 1k file and 4k block size it would report 8 > 512-byte blocks, gluster just reports 2 blocks. > > Avati > > On Mon, Nov 25, 2013 at 7:18 AM, Maik Kulbe > <info at linux-web-development.de> wrote: > > Hi, > > I've come to notice that the file system block size reported from stat > on a client is 128k, which is pretty high for the small files I use. > On > the other hand, I tested copying smaller files to the volume and it > seems those 128k are not the real block size - when I copy two 64k > files > to the volume `df` reports only a change after both files have been > copied. > > So my question would be what is the real block size for the Gluster > volume? The block size of the underlying xfs? Or something else? And > is > it possible to read the real block size? We wanted to use the block > size > reported by stat to calculate the real file size use on disk but it > seems that is not possible with Gluster.. > > Thank you in advance, > Maik > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://supercolony.gluster.org/mailman/listinfo/gluster-users
