Stephen John Smoogen wrote: > On 20 September 2017 at 10:47, hw <hw at gc-24.de> wrote: >> >> Hi, >> >> xfs is supposed to detect the layout of a md-RAID devices when creating the >> file system, but it doesn´t seem to do that: >> >> >> # cat /proc/mdstat >> Personalities : [raid1] >> md10 : active raid1 sde[1] sdd[0] >> 499976512 blocks super 1.2 [2/2] [UU] >> bitmap: 0/4 pages [0KB], 65536KB chunk >> >> >> # mkfs.xfs /dev/md10p2 >> meta-data=/dev/md10p2 isize=512 agcount=4, agsize=30199892 >> blks >> = sectsz=512 attr=2, projid32bit=1 >> = crc=1 finobt=0, sparse=0 >> data = bsize=4096 blocks=120799568, imaxpct=25 >> = sunit=0 swidth=0 blks >> naming =version 2 bsize=4096 ascii-ci=0 ftype=1 >> log =internal log bsize=4096 blocks=58984, version=2 >> = sectsz=512 sunit=0 blks, lazy-count=1 >> realtime =none extsz=4096 blocks=0, rtextents=0 >> >> >> # mkfs.xfs -f -d su=64m,sw=2 /dev/md10p2 >> meta-data=/dev/md10p2 isize=512 agcount=16, agsize=7553024 >> blks >> = sectsz=512 attr=2, projid32bit=1 >> = crc=1 finobt=0, sparse=0 >> data = bsize=4096 blocks=120799568, imaxpct=25 >> = sunit=16384 swidth=32768 blks >> naming =version 2 bsize=4096 ascii-ci=0 ftype=1 >> log =internal log bsize=4096 blocks=58984, version=2 >> = sectsz=512 sunit=8 blks, lazy-count=1 >> realtime =none extsz=4096 blocks=0, rtextents=0 >> >> >> The 64MB chunk size was picked my mdadm automatically. The device is made >> from two disks, and xfs either doesn´t figure that out, or it decided to >> ignore the layout of the underlying RAID. >> >> Am I doing something wrong here, or is xfs in Centos somehow different? >> Do, or must, we always specify the apporpriate values for su and sw or >> did xfs ignore them because what it picked is better? >> > > I don't know enough to answer, but I do have a question.. what were > you expecting xfs to do (and what filesystems do that?) Thanks I was expecting that the correct stripe size and stripe width would be used.