centos7中自带的有qla2xxx驱动，但是没有tcm_qla2xxx驱动,这会创建一些HBA卡的target的时候失败。为此，需要保证tcm_qla2xxx.ko驱动能生成并自动执行。那么该如何解决这个问题呢？
1.选择tcm_qla2xxx模块
首先，进入和当前centos内核版本和配置选项一致的源代码的build目录：
cd/lib/modules/3.10.0-229.el7.x86_64/build
make menuconfig
加上对tcm_qla2xxx的支持：
2.编译tcm_qla2xxx驱动
保存上面的选择，然后退出。接着cd /home/qbaq/qla2xxx:
make -C /lib/modules/3.10.0-229.el7.x86_64/build M=`pwd` modules
会看到下面的提示：
Building modules, stage 2.
MODPOST 2 modules
WARNING: "btree_init" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_insert" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_update" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_lookup" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_destroy" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_get_prev" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_remove" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_last" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
WARNING: "btree_geo32" [/home/qbaq/qla2xxx/tcm_qla2xxx.ko] undefined!
CC /home/qbaq/qla2xxx/qla2xxx.mod.o
LD [M] /home/qbaq/qla2xxx/qla2xxx.ko
CC /home/qbaq/qla2xxx/tcm_qla2xxx.mod.o
LD [M] /home/qbaq/qla2xxx/tcm_qla2xxx.ko
make: Leaving directory `/usr/src/kernels/3.10.0-229.el7.x86_64'
[root@localhost qla2xxx]# insmod ./tcm_qla2xxx.ko
insmod: ERROR: could not insert module ./tcm_qla2xxx.ko: Unknown symbol in module
[root@localhost qla2xxx]# dmesg | tail -n 10
[ 3907.642678] tcm_qla2xxx: Unknown symbol btree_get_prev (err 0)
[ 3935.279739] tcm_qla2xxx: Unknown symbol btree_last (err 0)
[ 3935.279763] tcm_qla2xxx: Unknown symbol btree_insert (err 0)
[ 3935.279884] tcm_qla2xxx: Unknown symbol btree_remove (err 0)
[ 3935.279911] tcm_qla2xxx: Unknown symbol btree_geo32 (err 0)
[ 3935.279946] tcm_qla2xxx: Unknown symbol btree_lookup (err 0)
[ 3935.279960] tcm_qla2xxx: Unknown symbol btree_init (err 0)
[ 3935.280066] tcm_qla2xxx: Unknown symbol btree_destroy (err 0)
[ 3935.280080] tcm_qla2xxx: Unknown symbol btree_update (err 0)
[ 3935.280142] tcm_qla2xxx: Unknown symbol btree_get_prev (err 0)
可以看大上面tcm_qla2xxx的一些符合依赖于btree这个模块。为此，需要继续解决对btree的依赖。尝试和上面同样的方法，重新进入build/:
make menuconfig
不过这次，在本地编译就会产生问题：
[root@localhost lib]# make -C /lib/modules/3.10.0-229.el7.x86_64/build M=`pwd` modules
make: Entering directory `/usr/src/kernels/3.10.0-229.el7.x86_64'
CC [M] /home/qbaq/lib/crc-ccitt.o
CC [M] /home/qbaq/lib/crc-t10dif.o
CC [M] /home/qbaq/lib/crc-itu-t.o
CC [M] /home/qbaq/lib/libcrc32c.o
CC [M] /home/qbaq/lib/crc8.o
CC [M] /home/qbaq/lib/ts_kmp.o
CC [M] /home/qbaq/lib/ts_bm.o
CC [M] /home/qbaq/lib/ts_fsm.o
CC [M] /home/qbaq/lib/cordic.o
CC [M] /home/qbaq/lib/raid6/algos.o
CC [M] /home/qbaq/lib/raid6/recov.o
HOSTCC /home/qbaq/lib/raid6/mktables
TABLE /home/qbaq/lib/raid6/tables.c
CC [M] /home/qbaq/lib/raid6/tables.o
UNROLL /home/qbaq/lib/raid6/int1.c
awk: fatal: can't open source file `/usr/src/kernels/3.10.0-229.el7.x86_64//home/qbaq/lib/raid6/unroll.awk' for reading (No such file or directory)
make[2]: *** [/home/qbaq/lib/raid6/int1.c] Error 1
make[1]: *** [/home/qbaq/lib/raid6] Error 2
make: *** [_module_/home/qbaq/lib] Error 2
3.解决tcm_qla2xxx对btree模块的依赖
究其原因，btree模块在tcm_qla2xxx选上之后，默认必须应该变成build in的，因为它可能依赖其他的内容。我们看这个文件包含的头文件也可以看出来：
所以，还需要重新编译内核。为了尽量保证和发行版的配置文件一致，我们把经过上面操作之后/lib/module/3.10.0-229.el7.x86_64 /build下最新的.confg拷贝过来:
然后make -j 32
make bzImage
make modules_install
make install
这样就能保证生成的内核里已经包含了btree模块，同时由于它会在启动时候加载，后续加载tcm_qla2xxx驱动就不会有问题了。
