** Phase 5-- Check Cyl groups
The fsck(1M) command is checking a file system, and fsck(1M) is now checking the free-block and used-inode maps. You might be asked to salvage free blocks or summary information.
You can usually answer "yes" to all these questions without harming the file system.
For more information, see the chapter on checking file system integrity in the System Administration Guide, Volume 1.