系统管理指南：设备和文件系统

自动搜索备份超级块

以下 fsck 错误消息示例说明了自动搜索备份超级块的功能。

注意 –

如果文件系统包含损坏的超级块，并且该超级块是使用 newfs 或 mkfs 自定义参数（如 ntrack 或 nsect）创建的，则使用 fsck 自动搜索的超级块执行修复过程可能会损坏文件系统。

如果文件系统是使用自定义参数创建的，并且包含错误的超级块，则 fsck 会提供取消 fsck 会话的提示：

CANCEL FILESYSTEM CHECK?

如果文件系统是使用 newfs 命令创建的，并且 fsck 响应表明只是主超级块已损坏，请考虑使用 fsck 恢复超级块。

# fsck /dev/dsk/c1t2d0s0

** /dev/rdsk/c1t2d0s0

BAD SUPERBLOCK AT BLOCK 16: BLOCK SIZE LARGER THAN MAXIMUM SUPPORTED



LOOK FOR ALTERNATE SUPERBLOCKS WITH MKFS? no





LOOK FOR ALTERNATE SUPERBLOCKS WITH NEWFS? yes



FOUND ALTERNATE SUPERBLOCK 32 WITH NEWFS



USE ALTERNATE SUPERBLOCK? yes



FOUND ALTERNATE SUPERBLOCK AT 32 USING NEWFS

If filesystem was created with manually-specified geometry, using

auto-discovered superblock may result in irrecoverable damage to

filesystem and user data.



CANCEL FILESYSTEM CHECK? no



** Last Mounted on

** Phase 1 - Check Blocks and Sizes

** Phase 2 - Check Pathnames

** Phase 3a - Check Connectivity

** Phase 3b - Verify Shadows/ACLs

** Phase 4 - Check Reference Counts

** Phase 5 - Check Cylinder Groups

CORRECT GLOBAL SUMMARY

SALVAGE? y





UPDATE STANDARD SUPERBLOCK? y



81 files, 3609 used, 244678 free (6 frags, 30584 blocks, 0.0% 

fragmentation)



***** FILE SYSTEM WAS MODIFIED *****

如果文件系统是使用 mkfs 命令创建的，并且 fsck 响应表明只是主超级块已损坏，请考虑使用 fsck 恢复超级块。

# fsck /dev/dsk/c1t2d0s0

** /dev/rdsk/c1t2d0s0

BAD SUPERBLOCK AT BLOCK 16: BLOCK SIZE LARGER THAN MAXIMUM SUPPORTED



LOOK FOR ALTERNATE SUPERBLOCKS WITH MKFS? yes



FOUND ALTERNATE SUPERBLOCK 32 WITH MKFS



USE ALTERNATE SUPERBLOCK? yes



FOUND ALTERNATE SUPERBLOCK AT 32 USING MKFS

If filesystem was created with manually-specified geometry, using

auto-discovered superblock may result in irrecoverable damage to

filesystem and user data.



CANCEL FILESYSTEM CHECK? no



** Last Mounted on

** Phase 1 - Check Blocks and Sizes

** Phase 2 - Check Pathnames

** Phase 3a - Check Connectivity

** Phase 3b - Verify Shadows/ACLs

** Phase 4 - Check Reference Counts

** Phase 5 - Check Cylinder Groups

CORRECT GLOBAL SUMMARY

SALVAGE? y





UPDATE STANDARD SUPERBLOCK? y



81 files, 3609 used, 243605 free (117 frags, 30436 blocks, 0.0% 

fragmentation)



***** FILE SYSTEM WAS MODIFIED *****

以下示例说明在超级块已损坏的情况下指定 fsck 的 -y 选项时将发生的情况。您将自动从 fsck 会话退出。此时会显示一条消息，指示使用替代超级块重新运行该命令。

# fsck -y /dev/dsk/c1t2d0s0

# 

** /dev/rdsk/c1t2d0s0

BAD SUPERBLOCK AT BLOCK 16: BLOCK SIZE LARGER THAN MAXIMUM SUPPORTED



LOOK FOR ALTERNATE SUPERBLOCKS WITH MKFS?  yes





LOOK FOR ALTERNATE SUPERBLOCKS WITH NEWFS?  yes



SEARCH FOR ALTERNATE SUPERBLOCKS FAILED.



USE GENERIC SUPERBLOCK FROM MKFS?  yes



CALCULATED GENERIC SUPERBLOCK WITH MKFS

If filesystem was created with manually-specified geometry, using

auto-discovered superblock may result in irrecoverable damage to

filesystem and user data.



CANCEL FILESYSTEM CHECK?  yes



Please verify that the indicated block contains a proper

superblock for the filesystem (see fsdb(1M)).



FSCK was running in YES mode.  If you wish to run in that mode using

the alternate superblock, run `fsck -y -o b=453920 /dev/rdsk/c1t2d0s0'.

以下 fsck 错误消息情况说明备份超级块的新提示，但在此示例中并未取消运行 fsck。如果此文件系统是使用自定义参数创建的，或者在此文件系统上运行 fsck 可能会带来其他问题，则应取消 fsck 会话。

以斜体提供的各种超级块错误情况如下所示：

# fsck /dev/rdsk/c0t1d0s0



** /dev/rdsk/c0t1d0s0



BAD SUPERBLOCK AT BLOCK 16: BLOCK SIZE LARGER THAN MAXIMUM SUPPORTED

BAD SUPERBLOCK AT BLOCK 16: NUMBER OF DATA BLOCKS OUT OF RANGE

BAD SUPERBLOCK AT BLOCK 16: INODES PER GROUP OUT OF RANGE

BAD SUPERBLOCK AT BLOCK 16: MAGIC NUMBER WRONG

BAD SUPERBLOCK AT BLOCK 16: BAD VALUES IN SUPER BLOCK

BAD SUPERBLOCK AT BLOCK 16: NCG OUT OF RANGE

BAD SUPERBLOCK AT BLOCK 16: CPG OUT OF RANGE

BAD SUPERBLOCK AT BLOCK 16: NCYL IS INCONSISTENT WITH NCG*CPG

BAD SUPERBLOCK AT BLOCK 16: SIZE OUT OF RANGE

BAD SUPERBLOCK AT BLOCK 16: NUMBER OF DIRECTORIES OUT OF RANGE

BAD SUPERBLOCK AT BLOCK 16: ROTATIONAL POSITION TABLE SIZE OUT OF RANGE

BAD SUPERBLOCK AT BLOCK 16: SIZE OF CYLINDER GROUP SUMMARY AREA WRONG

BAD SUPERBLOCK AT BLOCK 16: INOPB NONSENSICAL RELATIVE TO BSIZE



LOOK FOR ALTERNATE SUPERBLOCKS WITH MKFS? yes



FOUND ALTERNATE SUPERBLOCK 32 WITH MKFS



USE ALTERNATE SUPERBLOCK? yes



FOUND ALTERNATE SUPERBLOCK AT 32 USING MKFS

If filesystem was created with manually-specified geometry, using

auto-discovered superblock may result in irrecoverable damage to

filesystem and user data.



CANCEL FILESYSTEM CHECK? no



** Last Mounted on 

** Phase 1 - Check Blocks and Sizes

** Phase 2a - Check Duplicated Names

** Phase 2b - Check Pathnames

** Phase 3a - Check Connectivity

** Phase 3b - Verify Shadows/ACLs

** Phase 4 - Check Reference Counts

** Phase 5 - Check Cylinder Groups



SALVAGE? yes





UPDATE STANDARD SUPERBLOCK? yes



82 files, 3649 used, 244894 free (6 frags, 30611 blocks, 0.0% 

fragmentation)



***** FILE SYSTEM WAS MODIFIED *****