当配置多个vlan时候，在?入exit或apply时候经常会出现下面的出错信息，使得无法创建新的vlan
SW1(vlan)#exit
% not enough space on flash to store vlan database. trying squeeze...First create squeeze log by erasing the entire device

% error squeezing flash - (Missing Ｏr corrupted log)
Error on database apply 40: NV storage failure
Use /'abort/' command to exit
SW1(vlan)#

sw1#erase flash:
Erasing the flash filesystem will remove all files! Continue? [confirm]
Erasing device... eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee ...erased
Erase of flash: complete
解决办法:出现错误时候，?入abort先退到特权模式，然后打入erase flash，点确定完，再进入vlan database配置vlan即可。