Insecure reboot boot

Insecure reboot boot-Linux Enterprise Application-Linux server application information. The following is a detailed description. Prepare to upgrade the database to 9201 on the aix5L platform. This kind of thing has been done a lot. I didn't think there would be any problems, but I still encountered it. Fortunately, not a problem.

The customer's database is not large, but it is special that there are multiple databases running on this host, so we need to close all databases before upgrading. Shut down all databases in a normal way, prepare the upgraded file package, and prepare all directories.
As recommended, we plan to restart the host to ensure that the resource usage is completely released. Follow my usual habits to directly reboot the host.

After waiting for a while, it is estimated that the host is up and connected, and it has been successfully started. This is the intention to upgrade the database. At this moment, su-oracle reported an error, the Home Directory of the oracle user cannot be found. Strange, why can't I find it? I checked it and did not see the directory. I didn't see the disk area in the directory using df-k. What happened?

I thought about whether the disk was not mounted. I used the mount command to check whether the disk was mounted. Is it necessary to manually mount the disk? Ask the customer that the mount should be automatically available. It seems that there is still a problem. In any case, manually mount it first. As a result, an error is reported during storage mounting, the storage superblock has an exception and needs to be repaired.

Fortunately, the problem is not serious. Use fsck to verify and fix the Bad blocks. Solve the Problem and mount the storage.

Previously, reboot was used to restart because a large number of saloris and linux databases have been processed in the past. This type of OS can be directly reboot, but on aix, reboot is not executed in the same way, in the aix system, reboot is not equal to shutdown + startup, but to shutdown abort + startup. That is to say, when the host is shut down, reboot does not completely write the cached data to the disk, therefore, after the host is started, some storage may have logical block faults or incomplete OS blocks. If the faulty block is a superblock, the storage may not be attached.

The correct method for restarting the host is shutdown-Fr. Other related commands are as follows:

# Shutdown-m + 5 the system will be shut down to single user mode five minutes later
# Shutdown-r reboot after shutdown
# Shutdown now shut down immediately
# Shutdown-k give up shutdown

If there is no important data on the OS and it needs to be restarted quickly, you can select reboot.