Week 5 - Planning for Data Recovery Flashcards
What is data recovery?
The process of trying to restore data after an unexpected event results in data loss/corruption
What 2 factors determine how you can recover lost data?
- Nature of the data loss
- Presence of backups
What’s the best way to prepare for a data loss event?
Have a well-thought-out disaster plan and procedure (like regular backups of critical data)
What is a post-mortem?
A way to document any problems that were discovered along the way to implementing a disaster plan (for example) and how to fix them
What 3 questions do you ask when backing up data?
- What data do you need to back up?
- How much total data do you currently have? Flexibility to accommodate larger data backups in the future
- How often should you back up? How long to hold onto backups?
What type of backups are recommended if they’re within your organization’s budget? (2)
Both on-site and off-site backups
How would you set up a simple on-site/self-managed backup?
as simple as buying a commercial NAS (network-attached storage) device, loading it with a bunch of hard drives, and sending data to it over the network
What’s one approach to back up time periods (how long to hang onto backups) that balances cost with convenience?
archive older data using a slower but cheaper storage mechanism
What are data tapes?
Similar to cassette tapes, they use pools of magnetic tape run through machines that allow data to be written/read
The standard medium for archival backup data storage is ___ ___
data tapes
What type of data is stored on data tapes?
Data that isn’t likely to be needed, used for long-term archival purposes
What is rsync? (Linux)
a file transfer utility that efficiently transfers and synchronizes files between locations/computers
(a command)
Does rsync support SSH? (Linux)
Yes (to transfer data securely over the network)
How can you use rsync for backup? (Linux)
It supports SSH so it can synchronize files between remote machines for simple, automated backup
What is Time Machine? What backup model does it support? (2)
Apple’s first-party backup solution for macOS that uses an incremental backup model
What type of backup does Time Machine support in restoring?
supporting restoring an entire system from backup or individual files
What is Microsoft’s backup solution called?
Backup and Restore
What are the 2 modes of operation for Backup and Restore from Microsoft?
- file-based, files are backed-up to a zip archive
- system image, the entire disk is saved block-by-block to a file
What’s the restoration procedure?
It should be documented and accessible so anyone with the right access can restore operations when needed
What should you always do as a safeguard for your backups? (What is Disaster Recovery Testing?)
Make sure you regularly document and test your backups
(this process is called Disaster Recovery Testing)
What are the 3 ways to perform regular backups on data that’s constantly changing?
- Full Backup
- Differential Backup
- Incremental Backup
What is a con of doing a full backup of data that doesn’t change often?
You’re backing up multiple copies of data that isn’t changing which wastes space and bandwidth
What is differential backup?
Only files that are changed are backed up
If you have differential backup, should you stop taking full backups?
No, you should perform infrequent full backups with more frequent differential backups to avoid storing lots of copies of files that change a lot
What’s a good plan for backups when using full backups and differential backups so you only lose 24 hours of data changes?
Full backups once a week and differential backups daily (only lose 24 hours of data changes)
What are regular incremental backups?
only backs up the data that’s changed in the files since the last incremental backup
What’s the difference between differential and incremental backups?
Differential = files that have been changed or created since last full backup
Incremental = only data that’s changed in files since last incremental backup
Which is more efficient in terms of disk space and time between differential and incremental backups?
Incremental
How would you use incremental backups in a backup plan?
Combine frequent incremental backups along with less frequent full backups
What are 2 cons of using incremental backups?
might need all, if one of the backups
- Might need all incremental backups to fully reconstruct the files (since each backup stores a puzzle piece of a file)
- If one of the inc. backups is missing/corrupt, might not be able to recover data any more recently than last full backup
Why might incremental backups be more time-consuming?
The full backup and incremental backups have to be recreated by integrating both backup types to make the most recent version of backed-up data
(worse for large files)
When creating a backup, all files and folder structures will be copied and put into an ____. Why?
archive, keeps files organized and keeps folder structure
Backups can also be ______
compressed (not all data types though, depends on what’s being backed up)
What can you use when you want to restore data? (2)
TV, serve
- commercial NAS device
- configure a file server with large amount of disk space
Is RAID a backup solution?
NO, it’s a data storage solution with some hardware failure redundancy
Is RAID considered a replacement for backups?
No
What are 2 benefits of using a RAID array?
- Inexpensive to create lots of data capacity and minimizes the risk of data loss from disk failures
- Flexible to allow future growth in disk capacity
Does storing data on a RAID array protect from accidental file deletion or malware corruption?
No
What’s a good solution for user backups?
Use a cloud service designed for syncing and backing up files across platforms and devices
(like dropbox, icloud, google drive)
