backup interview questions

Top backup frequently asked interview questions

SQL Server (2005/2008): Does full backup truncate the log in full recovery mode

I've just read through a lot of MSDN documentation and I think I understand the different recovery models and the concept of a backup chain. I still have one question:

Does a full database backup truncate the transaction log (using full recovery mode)?

  • If yes: Where is this mentioned in the MSDN? All I could find was that only BACKUP LOG truncates the log.

  • If no: Why? Since a full database backup starts a new backup chain, what's the point in keeping the transactions that were finshed before the full backup active in the log?

Source: (StackOverflow)

Backing up a 22 GB MySQL database daily

Right now I am able to do the backup using mysqldump. But I have to take down the web server AND it takes around 5 minutes to do the backup. If I don't take down the web server, it takes forever and never finishes + the website becomes inaccessible during the backup.

Is there a quicker/better way to backup my 22 GB and growing database?

All the tables are MyISAM.

Source: (StackOverflow)


How do I back up an AWS S3 Bucket without versioning the source bucket [closed]

Is there any way to recover from accidental deletions of an Amazon S3 Bucket?

We've got critical info in our buckets and I need to mitigate the risk of accidental or malicious deletions of the bucket itself.

I know I can sync the entire bucket locally, but this isn't too practical if my bucket size is 100GB.

Any ideas on backup strategies?

Source: (StackOverflow)

Is it safe to store data on a hard drive for a long time?

Is it safe to backup data to a hard drive and then leave it for a number of years?

Assuming the file system format can still be read, is this a safe thing to do. Or is it better to continually rewrite the data (every 6 months or so) to make sure it remains valid?

Or is this a stupid question?

Source: (StackOverflow)

How does dropbox version/upload large files? [closed]

I have a free dropbox account (2GB), and I was wondering how the versioning of large files works.

I have a full backup of all my webfiles that sites @ just over 1GB. After the initial upload of 1GB, everytime it syncs will dropbox figure out the delta of the file, or will it have to upload the entire thing again to version it?

It would be cool to always have an up to date version of a large file, but I dont want to kill my bandwidth uploading 1GB everytime.

Is this possible?


Source: (StackOverflow)

Linux - What directories should I exclude when backing up a server?

I'm backing up a linux server and storing it on some other server. I started off with a simple

rsync -aPh --del server.example.com:/ /mnt/backup

Then someone pointed out that I shouldn't back up /proc, since you don't want to restore the /proc of one server on another.

Is there anything else that I should / shouldn't include? What about /sys?

Source: (StackOverflow)

How do I protect business critical data against fire?

We have 72 hard drives that contain our webcast inventory. The number is increasing. We're located in a frame building and we are afraid of not only fire, but catastrophic fire.

I've priced fireproof safes that hold to the required 125F for hard drives. Their price is through the roof.

Seems to me if we made backups of each of the hard drives and stored them off-site somewhere, or contracted with an online backup storage company, we might run up a bill buying backup drives that would approach the $7,000 cost of the safe!

What's the best way to protect our data from the risk of fire?

Source: (StackOverflow)

Why is RAID not a backup?

When someone mentions RAID in a conversation about backups, invariably someone declares that "RAID is not a backup."

Sure, for striping, that's true. But what's the difference between redundancy and a backup?

Source: (StackOverflow)

How to keep the full path with rsync?

When backing up with rsync, How do I keep the full directory structure?

For example, the remote server is saturn, and I want to backup saturn's /home/udi/files/pictures to a local directory named backup.

I want to have (locally) backup/home/udi/files/pictures rather than backup/pictures.

Source: (StackOverflow)

Best practices to keep your computer(s) backed up efficiently?

I'm looking for a cheap and efficient strategy to keep my personal computers and laptops backed up.

For example, currently I take a snapshot of my desktop once a week with Ghost and place the image on my external hard drive. Is this enough? Do you have any other suggestions?

Source: (StackOverflow)

Does an unplugged hard drive used for data archival deteriorate?

If I were to archive data on a hard drive, unplug it, and set it on a (not dusty, temperature-controlled) shelf somewhere, would that drive deteriorate much?

How does the data retention of an unplugged hard drive compare to tapes?

Source: (StackOverflow)

How to backup 20+TB of data?

We have a NAS server at the company I work for that is being used for storing photography sessions. Each session is approximately 100gb. Over the last couple of years this server has accumulated 10+ TB of data, and we are increasing the amount of photoshoots exponentially. I estimate that by the end of next year we will have 20+ TB stored on this NAS. We are currently backing this server up to tape using LTO-5 tapes with Symantec BackupExec. Since the size of this server has grown, full backups of this server are not completing overnight. Does anyone have any suggestion on how to backup this amount of data? Should we be backing it up to tape? Are there any other options which may be better?

Source: (StackOverflow)

GIT as a backup tool

On a server, install git

cd /
git init
git add .
git commit -a -m "Yes, this is server"

Then get /.git/ to point to a network drive (SAN, NFS, Samba whatever) or different disk. Use a cron job every hour/day etc. to update the changes. The .git directory would contain a versioned copy of all the server files (excluding the useless/complicated ones like /proc, /dev etc.)

For a non-important development server where I don't want the hassle/cost of setting it up on a proper backup system, and where backups would only be for convenience (I.E. we don't need to backup this server but it would save some time if things went wrong), could this be a valid backup solution or will it just fall over in a big pile of poop?

Source: (StackOverflow)

Confidential Documentation and the role of the Sysadmin

I've got another interesting one.

I'm about to backup and reinstall the HR Administrator's PC. I suspect that the fastest way to do this is to use the Windows 7 Transfer tool, and create a backup of the entire Users and Settings profiles on the NAS.

I don't see a problem with this.
She claims that nobody else should be able to see the information on her computer. Fair enough. I think that the systems administrator (me), should be in a significant enough level of trust to be able to make a backup, no questions asked, and delete the backup once the task is complete.

Her view is, that nobody (not even the other directors) should be able to view the HR documentation on her PC.

We already have a semi-backup (files, not user-state) on box.net, which does allow granular access to various users.


1) Which one of us is nuts, her or me?

2) Do you trust your sysadmins to take backups of company policy / HR files?

3) Does anyone have a LART?

Source: (StackOverflow)

protocol version mismatch -- is your shell clean?

When following the instructions to do rsync backups given here: http://troy.jdmz.net/rsync/index.html

I get the error "protocol version mismatch -- is your shell clean?"

I read somewhere that I needed to silence the prompt (PS1="") and motd (.hushlogin) displays to deal with this. I have done this, the prompt and login banner (MOTD) not longer appear, but the error still appears when I run:

rsync -avvvz -e "ssh -i /home/thisuser/cron/thishost-rsync-key" remoteuser@remotehost:/remote/dir /this/dir/

Both ssh client and sshd server are using version 2 of the protocol.

What could be the problem? Thanks.

[EDIT] I have found http://www.eng.cam.ac.uk/help/jpmg/ssh/authorized_keys_howto.html which directs that it is sometimes necessary to "Force v2 by using the -2 flag to ssh or slogin

 ssh -2 -i ~/.ssh/my_private_key remotemachine"

It is not clear this solved the problem as I think I put this change in AFTER the error changed but the fact is the error has evolved to something else. I'll update this when I learn more. And I will certainly try the suggestion to run this in an emacs shell - thank you.

Source: (StackOverflow)