Solaris10镜像情况下如何修复boot archive

在某些情况下(比如：异常宕机)solaris10的boot archive可能会损坏，导致solaris无法启动，此时需要手工修复boot archive。
本文通过模拟boot archive损坏，测试如何在root镜像存在的情况下恢复boot archive. (本测试在x86虚拟机上进行)
测试分为四部分。第一部分是solaris10做root镜像，第二部分通过dd命令模拟boot archive损坏，第三部分是拆除镜像和修复boot archive,第四部分是修复root镜像

1. 系统盘镜像

1) 硬盘分区情况

c1t0d0s0  /
c1t0d0s1  swap
c1t0d0s7  metadb

2) 镜像盘创建solaris fdisk分区 (x86)

format -> 1(镜像盘) -> fdisk -> y

3) 将源盘分区表同步到镜像盘上

root@solaris10 # prtvtoc /dev/rdsk/c1t0d0s2 | fmthard -s - /dev/rdsk/c1t1d0s2
fmthard:  New volume table of contents now in place.

4) 创建metadb，放在slice7上

root@solaris10 # metadb -a -c 3 -f c1t0d0s7 c1t1d0s7
root@solaris10 # metadb -i
        flags           first blk       block count
     a        u         16              8192            /dev/dsk/c1t0d0s7
     a        u         8208            8192            /dev/dsk/c1t0d0s7
     a        u         16400           8192            /dev/dsk/c1t0d0s7
     a        u         16              8192            /dev/dsk/c1t1d0s7
     a        u         8208            8192            /dev/dsk/c1t1d0s7
     a        u         16400           8192            /dev/dsk/c1t1d0s7
r - replica does not have device relocation information
o - replica active prior to last mddb configuration change
u - replica is up to date
l - locator for this replica was read successfully
c - replica's location was in /etc/lvm/mddb.cf
p - replica's location was patched in kernel
m - replica is master, this is replica selected as input
W - replica has device write errors
a - replica is active, commits are occurring to this replica
M - replica had problem with master blocks
D - replica had problem with data blocks
F - replica had format problems
S - replica is too small to hold current data base
R - replica had device read errors

5) 创建root分区镜像

root@solaris10 # metainit -f d11 1 1 c1t0d0s0
d11: Concat/Stripe is setup
root@solaris10 # metainit -f d12 1 1 c1t1d0s0
d12: Concat/Stripe is setup
root@solaris10 # metainit d10 -m d11
d10: Mirror is setup

6) 执行metaroot修改vfstab

root@solaris10 # metaroot d10

7) 重启

root@solaris10 # shutdown -i6 -g0 -y

8) 创建swap镜像

root@solaris10 # metainit -f d21 1 1 c1t0d0s1
d21: Concat/Stripe is setup
root@solaris10 # metainit -f d22 1 1 c1t1d0s1
d22: Concat/Stripe is setup
root@solaris10 # metainit d20 -m d21
d20: Mirror is setup

9) 修改vfstab文件

/dev/dsk/c1t0d0s1       -       -       swap    -       no      -
修改为=>
/dev/md/dsk/d20 -       -       swap    -       no      -

10) 重启

root@solaris10 # shutdown -i6 -g0 -y

11) 附加子镜像

root@solaris10 # metattach d10 d12
d10: submirror d12 is attached
root@solaris10 # metattach d20 d22
d20: submirror d22 is attached

12) 检查镜像

root@solaris10 # metastat

2. 模拟boot archive损坏

root@solaris10 # dd if=/dev/zero of=/platform/`uname -i`/boot_archive bs=1024 count=1
1+0 records in
1+0 records out

重启主机
root@solaris10 # shutdown -i6 -g0 –y

报错:

3. 修复boot archive

1) 启动到failsafe

启动时选择Solaris failsafe (x86)
ok boot -F failsafe (sparc)

2) 拆除镜像

# mount /dev/dsk/c1t0d0s0 /a

备份vfstab
# cp /a/etc/vfstab /a/etc/vfstab.svm

备份system
# cp /a/etc/system /a/etc/system.svm

修改vfstab文件，把所有md设备修改成slice
# TERM=vt100; export TERM
# vi /a/etc/vfstab

(如果不清楚md设备与slice的对应关系，可以cat /a/etc/lvm/md.cf)

如果vfstab与初始安装时一致，也可以用初始安装覆盖
# cp /a/etc/vfstab-INSTALL /a/etc/vfstab

修改system文件，注释掉(或者删除)rootdev:/pseudo/md@0:0,10,blk这一行。
# vi /a/etc/system

如果system与初始安装时一致，也可以用初始安装覆盖
# cp /a/etc/system-INSTALL /a/etc/system

3) 修复boot archive

删除boot archive
# rm -f /a/platform/`uname -i`/boot_archive

重建boot archive
# bootadm update-archive -R /a

重启
# shutdown -i6 -g0 –y

4. 修复镜像

1) detach子镜像

root@solaris10 # metadetach d10 d12
d10: submirror d12 is detached
root@solaris10 # metadetach d20 d22
d20: submirror d22 is detached

  2) 恢复原来的vfstab和system文件

root@solaris10 # mv /etc/system.svm /etc/system
root@solaris10 # mv /etc/vfstab.svm /etc/vfstab

3) 重启

root@solaris10 # shutdown -i6 -g0 –y

4) attach子镜像

root@solaris10 # metattach d10 d12
d10: submirror d12 is attached
root@solaris10 # metattach d20 d22
d20: submirror d22 is attached