On 8/29/2013 1:09 AM, Chris Murphy wrote:
>
> Is it expected when formatting, using defaults, that a thinp volume compared
> to either a conventional LV or partition of the same size, should have a
> higher agcount?
>
>
> HDD, GPT partitioned, 100GB partition size:
>
> [root@f19s ~]# mkfs.xfs /dev/sda7
> meta-data=/dev/sda7 isize=256 agcount=4, agsize=6553600 blks
> = sectsz=512 attr=2, projid32bit=0
> data = bsize=4096 blocks=26214400, imaxpct=25
> = sunit=0 swidth=0 blks
> naming =version 2 bsize=4096 ascii-ci=0
> log =internal log bsize=4096 blocks=12800, version=2
> = sectsz=512 sunit=0 blks, lazy-count=1
> realtime =none extsz=4096 blocks=0, rtextents=0
>
>
> A 400GB partition, made into PV, PV added to VG, and all extents put into a
> thinpool volume, a 100GB virtual sized LV:
>
> [root@f19s ~]# mkfs.xfs /dev/mapper/vg1-data
> meta-data=/dev/mapper/vg1-data isize=256 agcount=16, agsize=1638400 blks
> = sectsz=512 attr=2, projid32bit=0
> data = bsize=4096 blocks=26214400, imaxpct=25
> = sunit=0 swidth=0 blks
> naming =version 2 bsize=4096 ascii-ci=0
> log =internal log bsize=4096 blocks=12800, version=2
> = sectsz=512 sunit=0 blks, lazy-count=1
> realtime =none extsz=4096 blocks=0, rtextents=0
>
>
>
> I get agcount=4 on a conventional LV as well. Why agcount=16 on thinp?
More information would be helpful, specifically WRT the device stack
underlying mkfs.xfs. I.e. we need to know more about the LVM configuration.
See:
http://xfs.org/index.php/XFS_FAQ#Q:_What_information_should_I_include_when_reporting_a_problem.3F
--
Stan
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