How to mount XFS filesystem?

usao · 10-05-2015, 12:14 PM

# cat /etc/centos-release
CentOS release 6.7 (Final)

# sudo yum install xfsprogs
Package xfsprogs-3.1.1-16.el6.x86_64 already installed and latest version
Nothing to do

# lvs /dev/pool_vg/pool_lv
LV VG Attr LSize Pool Origin Data Meta% Move Log Cpy%Sync Convert
pool_lv pool_vg -wi-a----- 65.00t

# mkfs.xfs -b size=64k /dev/pool_vg/pool_lv
meta-data=/dev/pool_vg/pool_lv isize=256 agcount=65, agsize=16777215 blks
= sectsz=512 attr=2, projid32bit=0
data = bsize=65536 blocks=1090514880, imaxpct=1
= sunit=0 swidth=0 blks
naming =version 2 bsize=65536 ascii-ci=0
log =internal log bsize=65536 blocks=32608, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=65536 blocks=0, rtextents=0

# mount -t xfs /dev/pool_vg/pool_lv /pool
mount: Function not implemented

usao · 10-05-2015, 01:19 PM

Ok, I think the cause is the block size being set to 64k. For unknown reasons, this seems to foul-up the mount command abilities.
When I rebuild the FS using default block size, it does mount.

# mkfs.xfs -f /dev/pool_vg/pool_lv
meta-data=/dev/pool_vg/pool_lv isize=256 agcount=65, agsize=268435455 blks
= sectsz=512 attr=2, projid32bit=0
data = bsize=4096 blocks=17448238080, imaxpct=1
= sunit=1 swidth=256 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal log bsize=4096 blocks=521728, version=2
= sectsz=512 sunit=1 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
# mount -t xfs /dev/pool_vg/pool_lv /pool
# df -h /pool
Filesystem Size Used Avail Use Mounted on
/dev/mapper/pool_vg-pool_lv
65T 35M 65T 1% /pool

michaelk · 10-05-2015, 01:28 PM

You are correct, in a nutshell the kernel page cache limits block size which is as far as I know 4K.