问题现象
创建PV（物理卷）
[root]# pvcreate /dev/sdn
Device /dev/sdn excluded by a filter.因/dev/sdn之前创建过分区sdn1，后来删除了sdn1分区，pvcreate扫描/dev/sdn存在分区信息所以才忽略创建PV。
处理过程
将/dev/sdn格式华为一个分区
[root]# parted /dev/sdn
GNU Parted 3.1
Using /dev/sdn
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel msdos #支持msdos和gpt两种格式（msdos最大支持2T，gpt不受限）
Warning: The existing disk label on /dev/sdn will be destroyed and all data on this disk will be lost. Do you want to continue?
Yes/No? Yes
(parted) quit
Information: You may need to update /etc/fstab.
重新创建PV（物理卷）
[root]# pvcreate /dev/sdn
WARNING: dos signature detected on /dev/sdn at offset 510. Wipe it? [y/n]: y
Wiping dos signature on /dev/sdn.
Physical volume "/dev/sdn" successfully created.
