在使用crash工具分析vmcore时，常会遇到内核模块符号不能解析的问题，如：
crash> struct igbadapter 0xffff81032bef56b8
struct: invalid data structure reference: igbadapter
二、原因：
那是因为没有找到igb驱动模块的符号信息。原因为：只使用了vmlinux文件(包含内核符号)，而其它的单独加载的内核模块的符号信息实际是没有包含在vmlinux文件中的，需要使用单独加载。
模块的debug符号信息在kernel-debuginfo包(针对redhat系发行版)中有。所以，其实只需要安装kernel-debuginfo包就可以了。
三、解决
加载相应的符号信息后就即可正常访问。具体如下：
crash> mod -s igb /usr/lib/debug/lib/modules/2.6.18-164.el5/kernel/drivers/net/igb/igb.ko.debug
MODULE NAME SIZE OBJECT FILE
ffffffff88285380 igb 116181 /usr/lib/debug/lib/modules/2.6.18-164.el5/kernel/drivers/net/igb/igb.ko.debug
crash> struct igb_adapter
struct igb_adapter {
struct timer_list watchdog_timer;
struct timer_list phy_info_timer;
struct vlan_group *vlgrp;
u16 mng_vlan_id;
u32 bd_number;
u32 rx_buffer_len;
u32 wol;
u32 en_mng_pt;
u16 link_speed;
u16 link_duplex;
unsigned int total_tx_bytes;
unsigned int total_tx_packets;
unsigned int total_rx_bytes;
unsigned int total_rx_packets;
u32 itr;
u32 itr_setting;
u16 tx_itr;
u16 rx_itr;
struct work_struct reset_task;
struct work_struct watchdog_task;
bool fc_autoneg;
struct igb_adapter {
struct timer_list watchdog_timer;
struct timer_list phy_info_timer;
struct vlan_group *vlgrp;
u16 mng_vlan_id;
u32 bd_number;
u32 rx_buffer_len;
u32 wol;
u32 en_mng_pt;
u16 link_speed;
u16 link_duplex;
unsigned int total_tx_bytes;
unsigned int total_tx_packets;
unsigned int total_rx_bytes;
unsigned int total_rx_packets;
u32 itr;
u32 itr_setting;
u16 tx_itr;
u16 rx_itr;
struct work_struct reset_task;
struct work_struct watchdog_task;
bool fc_autoneg;
...