Common NAS failures
Cost-effective, functional and flexible; as a storage option, NAS is rarely beaten in these areas. However, as with most storage devices, data loss cannot be completely ruled out. Each case of data loss from NAS systems has its own history, but there are some frequently occurring scenarios that require a restoration of network storage. Here’s a few that are relatively common:
Human failure: Human error is a common cause when data from NAS or RAID systems is lost. Data loss often happens accidentally due to re-formatting, reinstallation or by accidentally overwriting data on the drives.
Power failure: NAS systems can encounter severe problems due to power failure or voltage fluctuations. RAID arrays that have been in use for some time are particularly vulnerable, as voltage fluctuations can prevent disks (which can be knocked out-of-sync) from being re-integrated into the RAID.
Overheating: Overheating of the system by faulty cooling in a server room, or by storing it in the wrong location in the office or at home, is quite a common occurrence. Consequences of this include hard disk overheating and the system failing, leading to data loss in some cases.
Defective NAS controllers: These can be a result of faulty reorganisations or rebuilds can cause data loss. Firmware or operating system errors by overwriting the memory configuration can also lead to information getting lost.
Mechanical faults: RAID systems are designed to compensate for the failure of a single hard disk. As soon as a NAS/RAID system is used in a degraded state (where a hard disk has failed), the remaining hard disks must compensate for the failure. This can lead to additional stress on the system and further disk failures, often ending in a total system failure.
Natural catastrophes: Fire damage, water damage and other contamination can destroy NAS systems in seconds. In these situations a system rebuild will require special knowledge and the ability to thoroughly clean and decontaminate the hardware –the data can then be restored by a logical rebuild. Professional data recovery service providers such as Kroll Ontrack have the technical capabilities to thoroughly clean and successfully restore media from even the worst data loss situations.
A few tips to avoid NAS data loss
These examples show that there are many reasons and situations where data loss can occur, even in a NAS system. A little caution can increase the data security enormously. To help you prepare against these types of scenarios, we have put together some tips on how to minimise the risk of data loss:
- Control access rights: If the network storage is shared between several users, it should be clear who can access what data. Data is often deleted because a user does not know that another person needs it.
- Create automatic backups: NAS systems offer many advantages, but there is no absolute data security. Therefore, it is recommended to periodically back up all important data on other storage media such as USB hard disks. Even more security can be achieved if the backup is spatially separated. Also, data should be encrypted when it is being stored in an external location.
- Correct setup: Often a NAS is built in the form of a RAID system (Redundant Array of Independent Disks), with a defined RAID level. In the best case this ensures additional security, which is essential for companies. However, remember that RAID 0 does not provide any data security! RAID 0 allows faster data access, but does not provide any redundancies or mirroring. RAID 5 is the better choice, but regardless, an external backup should not be forgotten.
- Trust is good, control is better: Backups should always be tested for their functionality; an incomplete or inaccessible backup is not worth anything. At the same time, extended NAS solutions should also be tested by experienced personnel before the final set up and operation. Incorrect expansion can lead to a complete failure and most likely a loss of data.
- Correct documentation: Each administrator should document the NAS system used. Important, frequently forgotten details include the BIOS version, controller version and file systems used. Exact documentation facilitates data recovery if necessary and also plays an important role in compliance.
- Proper investment: It doesn’t pay to be thrifty with storage in the long run. Therefore, you should pay attention to quality when buying hard disks for your storage system. The most suitable hard disks are the ones that are able to be run continuously, have fast access times and a large cache. It is best to purchase hard disks from different production batches, as eventually any production-related errors or susceptibility to failures can be reduced.
- Standardise: It is recommended to use standardised disks with Microsoft file systems or Linux EXT3 or XFS. Alternative, proprietary formats with little or often non-documented file systems make any data recovery attempts more time-consuming and costly in case of an emergency.
- Be prepared: In case of an emergency, a trusted data recovery service provider should be available to you immediately, no matter what time of day (or night). This allows the necessary recovery measures to be initiated quickly and it protects you from making any mistakes. Do you have a data recovery provider that you can call on 24/7/365? Are you sure that they can work with your system? Their information should be in a dedicated section of any disaster recovery plan.
- Keep calm: In the case of supposed data loss, try not to panic. It is important to remember that you should not try to recover the data yourself – in most cases a data recovery is still possible, but it is no longer possible even for professionals after various DIY rescue attempts with tips from colleagues or from the Internet. It is best to safely disconnect the system from the power line and commission an expert service provider to carry out at least an initial data recovery analysis.
You can find more tips on how to protect against data loss in NAS systems on the Kroll Ontrack website.
Has your organisation ever lost data on a NAS system? What backup systems and processes do you protect your data with? Let us know by commenting below, or tweet @DrDataRecovery
Image credit: Nöhren / pixelio.de
Michael Nuncic is Marketing Communications Manager at the German Ontrack Data Recovery office in Böblingen for more than 5 years. Highly experienced in computer, network and software topics, he is a professional editor for blog and technical articles for almost 20 years now.