I got a bug report that REAR was trying to recreate an xfs filesystem
geometry by looking at the xfs_info from the original filesystem.
In this case, the original fs was:
meta-data=/dev/mapper/vg-lv_srv isize=512 agcount=400, agsize=6144 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1 bigtime=1 inobtcount=1
data = bsize=4096 blocks=2453504, imaxpct=25
= sunit=16 swidth=16 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=1872, version=2
= sectsz=512 sunit=16 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
(horribly pessimal, almost certainly the result of xfs_growfs)
But the point is, the last AG is only 8MB. However, mkfs.xfs refuses to
make an AG less than 16MB. So, this fails, because agcount was specified
and mkfs won't reduce it to fix the too-small AG:
# truncate --size=10049552384 fsfile
# mkfs.xfs -f -m uuid=23ce7347-fce3-48b4-9854-60a6db155b16 -i size=512
-d agcount=400 -s size=512 -i attr=2 -i projid32bit=1 -m crc=1 -m
finobt=1 -b size=4096 -i maxpct=25 -d sunit=128 -d swidth=128 -l
version=2 -l sunit=128 -l lazy-count=1 -n size=4096 -n version=2 -r
extsize=4096 fsfile
mkfs.xfs: xfs_mkfs.c:3016: align_ag_geometry: Assertion
`!cli_opt_set(&dopts, D_AGCOUNT)' failed.
I think this is the result of mkfs.xfs using 16MB as a limit on last AG
size:
#define XFS_AG_MIN_BYTES ((XFS_AG_BYTES(15))) /* 16 MB */
#define XFS_AG_MIN_BLOCKS(blog) (XFS_AG_MIN_BYTES >> (blog))
But growfs uses this:
#define XFS_MIN_AG_BLOCKS 64
(which is much smaller than 16MB).
This should almost certainly be consistent between mkfs and growfs, and
my guess is that growfs should start using the larger XFS_AG_MIN_BLOCKS
requirement that mkfs.xfs uses?
Thanks,
-Eric
