More info:
The output of the "problematic" LV is:
$ lvs -o seg_size,vg_extent_size --units s --nosuffix \
> /dev/data/mail
SSize Ext 4294967296 8192
And if I do not specify the LV (output of all LVs):
$ lvs -o seg_size,vg_extent_size --units s --nosuffix SSize Ext 1949696 8192 3221225472 8192 2147483648 8192 4294967296 8192 4294967296 8192 1050673152 8192 52428800 8192 52428800 8192 2147483648 8192 209715200 8192 10485760 8192 62914560 8192 41943040 8192 83886080 8192 10485760 8192 62914560 8192 1048576000 8192 1048576000 8192 97648640 8192
The problem only occurs when probing our biggest LV.
More info:
The output of the "problematic" LV is:
$ lvs -o seg_size, vg_extent_ size --units s --nosuffix \
> /dev/data/mail
SSize Ext
4294967296 8192
And if I do not specify the LV (output of all LVs):
$ lvs -o seg_size, vg_extent_ size --units s --nosuffix
SSize Ext
1949696 8192
3221225472 8192
2147483648 8192
4294967296 8192
4294967296 8192
1050673152 8192
52428800 8192
52428800 8192
2147483648 8192
209715200 8192
10485760 8192
62914560 8192
41943040 8192
83886080 8192
10485760 8192
62914560 8192
1048576000 8192
1048576000 8192
97648640 8192
The problem only occurs when probing our biggest LV.