It’s true: people still use Windows 2003. For one reason or another, be it obstinance or some other archaic piece of software, companies are forced to hold on to the Windows 2003 server operating system for much longer than many of us would like.
“Volume Shadow” was a nice feature incorporate in to Windows 2003 server. No additional client was needed. When enabled, you could right-mouse click on a file, select properties, and you were greeted with a window that has an additional tab labeled “Previous Version”.
At least, that was the promise. But, wait.. you’re looking. It’s not there. You’ve navigated to the folder, right-mouse clicked on the file, and there is no previous versions tab. Now you are thinking you need to go to a backup tape, and you are sweating a little bit over the validity of your backups.
Never mind what the age-old Tao of Backup tells us, we still sweat a little when having to turn to our backups. But then you are also positive Volume Shadow copy was enabled. So you check. You right-mouse click on “Computer” and select “Manage”, expand “Shared Folders”, right-mouse click on the drive, select “All tasks” and select “Configure volume shadow copy…” You look. You see it’s configured.
You scratch your head again. “Why am I not seeing the Previous Version tab?” you ask yourself. “Does it need a client?” So you navigate to C:\Windows\system32\twclient\twclient.msi and install it. As it is installing, you’re now thinking “But wait.. Windows 2003 included the client, didn’t it?” You are right.. it did. Installing the client doesn’t do any harm, though.
Still, there is no “Previous Versions” tab.
The Solution
Well, it seems that the ONLY way to see this tab is via the share itself. You cannot navigate to the file locally on the system and expect to see the “Previous Versions” tab. I’m guessing that the expectation was to provide this functionality to users directly, so the client would be installed on the Windows XP desktops.
On the server, select Start->run and enter “\\thisservername\thesharename\pathtofolder\”. When the folder opens, right-mouse click on the file, and you will now see the “Previous Versions” tab. Restore and breathe a little easier.
Now go make sure your backups are working. Just in case.
All it takes is just one interruption while writing that UPDATE line for a password, leaving off the critical WHERE clause, and suddenly all of your users are locked out. Or some other minor error that is inadvertently made. Whatever the cause, you are left with a mysql server that has all of your data, but it cannot serve it because all of the passwords are gone.
Admit it. You now have an outage that is likely your fault. Oh, well. No need to fret over what has happened, but you need to get out of this hole as quickly as possible.
Here is a sample backup script that will create an on-line archive of separate files of all of the databases, in separate files, within a directory tree, for easy parsing and recovery: mysql_backup.pl. It can certainly be modified to use more perl modules, but it works as is, too.
1. Communicate
People are going to quickly realize that either they do not have access to their databases or that, as users, they do not have access to their web applications. While you may be able to pound out 145 words per minute in your command-line skills and may also secretly hope to recover without having to admit your embarrassing mistake, don’t waste your time.
Focus on getting the problem resolved. This cannot be stressed enough.
Send out a quick email, something that can be done in 30 seconds or less with your 145 words per minute skill, making everyone aware of the problem.
If you don’t, here is a summary of how it will play out:
You will have random people stopping by to tell you all about the problem typically starting with the phrase “I don’t know if you know about this or not..” or “I just wanted to let you know..” or “Hey, do you know when this will be fixed?” or any number of similar iterations.
These interruptions will increase in frequency the longer the outage.
As the number of interruptions increase, your stress level will increase.
You will attempt to work more feverishly to resolve the problem faster.
You will become more curt with the people reporting the problem (remember, these are your customers, and they are trying to be helpful in their own way).
Word will trickle upwards to management and possibly senior management. A perception, one not based upon reality, will begin to take hold about you and your skills. Remember, “Perception IS Reality”.
It is important to point out that this type of visibility to your users and your management is a BAD THING.. for you. While an outage is generally viewed as a bad thing, the perception that is being created by the lack of communication is worse.
2. Stop mysql
Bring down the database server. /etc/init.d/mysqld stop
3. Start mysql in “safe” mode
It sounds “windows-ish”, but it is true. Mysql can be started up without reading its grant tables, which gives the administrator the ability to connect in to the database without a password. No other users can connect at this time.
mysqld_safe --skip-grant-tables &
4. Find your backups
Hopefully, you take nightly backups of your databases. If not, this task will be harder.
4a. You want to get a copy of the backup of your ‘mysql’ database. In particular, you want the ‘user’ table. Place the file in /tmp or some place you can freely work.
4b. If you do not have a backup to restore from, you will need to locate all of the applications that rely on databases hosted by your mysql server and collect all of the user names and passwords.
5. Restore your ‘user’ table
If you have the ‘user’ table from the last backup, you will be simply restoring it over top of the current one.
mysql < /tmp/usertable.sql
After which, you will need to drop any users that were created between the time of the last backup and the time of this restore. Within mysql execute for each user:
drop user newuser@localhost; flush privileges;
Otherwise, you will need to manually update each row in the user table accordingly.
6. Restart mysql
Now that your mysql ‘user’ table is restored back to what it was from your previous backup, restart mysql:
/etc/init.d/mysqld restart
Congratulations! Your users and their web apps now have access again. You will need to add any users that were added after the time of the most recent backup.
Under linux, use the command “ssh-copy-id user@host” rather than playing around with the authorized_keys files and the id_dsa.pub or id_rsa.pub files. Â Life is so much easier.