RAID 6 vs RAID 5 - The Case For RAID 6

RAID-5 is the most popular choice for storage arrays today, as it is relatively simple to implement at the hardware level and is able to continue to operate in the event of failure of a single device. For many years RAID-5 has provided adequate levels of protection for highly reliable operation, but the growth in data storage requirements and the corresponding increase in capacity of arrays has the potential to impact the reliability of RAID-5 systems.

It is easy to see that larger data storage requirements leads to arrays with more drives and with more drives comes a higher probability of one drive failing. However, another problem is now becoming apparent - the rate at which an otherwise healthy occasionally drive fails to read a sector from the disk. These errors are known as "non-recoverable read errors" and the rate at which they occur is typically specified by the drive manufacturer as "non- recoverable read errors per bits read". This rate ranges from one error per 10^14 bits (12.5 TB) read for consumer SATA drives such as the Seagate Cheetah NS.

In order to rebuild the array after a drive failure, a RAID-5 array must read the entire contents of every remaining disk in the array. If the array consists of seven 1 TB disks, 6 TB of data would be read during this process, 1 TB from each of the six non-failed disks. If consumer SATA disks are used, one read in every 12.5 TB of data read is likely to fail, so there is almost a 50% chance of an unrecoverable read error during this process. When such an error occurs the RAID controller cannot continue the recovery process and the array will fail. When this happens, all is not lost. Our experienced data recovery experts can rebuild arrays which have failed in this way, often with same-day turnaround. Call us on 0800 999 3282 to discuss how we can get you back in business as quickly as possible.

RAID-6 improves on the reliability of RAID-5 by being able to tolerate failures on two disks simultaneously, thus considerably enhancing the reliability of the array. This enhanced reliability comes at the cost of additional hardware in the form of the additional disk per array, as well as increased complexity in the RAID controller.

In an ideal implementation, RAID-6 is only marginally slower than a RAID-5 array with the same capacity and identical drives. The minor performance penalty comes from the need to wait for data on one additional disk to rotate to the read heads. The complexity of the calculations required when writing data mean that real world implementations are often far from ideal and are limited in performance by the rate at which parity can be calculated, rather than the speed of the disks.

How RAID-6 works

While a RAID-5 array contains one additional drive, over and above those required to store the data, a RAID-6 array contains two additional drives. The capacity of an array consisting of N drives with minimum capacity C is thus given by the formula (N - 2) * C. For example, a RAID-6 array of seven 1 TB drives would have a usable storage capacity of 5 TB.

The following diagram illustrates how the data and parity blocks are distributed across disks in a RAID-6 system.

RAID 6

A Firmware Affair (RAID 0 Case Study)

Firmware issues

Sometimes it is very difficult to correctly diagnose a drive: the symptoms one is facing can be confusing and can lead you in the wrong direction.

We received a RAID 0 system, made up of 2 drives. One of them was completely unresponsive, it had no sign of life when powered on.

In such situations, the first issue that comes to mind is a major PCB failure; so you have two solutions: replace it with a matching PCB that you know works, or try to repair the damaged board.

Well, this time the PCB swap didn’t help at all.

We checked all the other components and they were fine; at the end of a long process we found that the problem was in the ROM chip: the firmware had suffered a severe corruption.

The word Firmware is related to a collection of small programs, this is what “controls" the hardware to put it simply. Usually, such microprograms are stored mainly on a Read Only Memory chip and partly on the platters.

Nowadays almost all modern intelligent devices have a firmware onboard that oversees the proper functioning of the device.

Maybe you have experienced it with your digital camera or mobile phone: A Firmware upgrade results in a totally new behaviour (hopefully better) of your device.

Well, in our drives case, the FW damages prevented the PCB working at all.
Here come the real issues. Every Hard disk firmware stores some unique information, belonging to that specific drive, vital to its correct functioning: you cannot simply take a FW from another drive and overwrite it.

So, we started a real handcraft job trying to reconstruct the damaged FW modules cutting and sewing from other drives.

Our efforts have been rewarded: the customer was very pleased to be able to have his data back in fully working condition!

R3 Data Recovery is real lab that deals with real disasters each an every day. If you have RAID that has failed or any data storage device, we are the people to contact. Call us today on 0800 999 3282 for immediate help and assistance.

Formatting Your Hard Drive Correctly

How To Format Your Hard Disk Drive

When a hard drive comes into the lab at R3 they can be internal, external, or part of a larger multi-drive set up, such as RAID or NAS.

To format a drive (hard disk, floppy disk, flash drive, etc.) basically means to ready the chosen partition on the drive to be used by an operating system (Windows, Mac etc.) It deletes all of the data on the disk already (if there is any) and sets up a file system. For example the most common file system to support Windows is NTFS. For Mac its HFS. However FAT 32 or exFAT can be used and supports both operating systems.

It’s important from the R3 lab’s perspective to find out what operating system the customer is using and therefore what filesystem they need, ideally before we have received the job. This allows the process of data transfer to be seamless and done as quickly as possible. If this information is not known the data could be transferred onto a hard drive with a particular file system, and then the hard drive be sent back out to the customer for use after the recovery and the customer then cannot access their data as it is not recognised by the operating system.

Wrongly formatted drive

This then causes issues for the customer, especially if they need their data back urgently. The only way to resolve a situation like this is to start the transfer of data again to a correctly formatted hard drive. Which in some cases depending on the number of files could be not hours but days.

An example recently of this, was a job we received last week. The hard drive was out of a water damaged MacBook. The recovery was thankfully relatively straightforward. As the data we recovered was from a MacBook the filesystem was HFS. So the recovered data was transferred to a new external hard drive that was formatted for a Mac operating system. This was sent back out to the customer. However what the customer didn’t inform us was that while the hard drive was at R3 getting recovered, they purchased a new laptop. It was a Windows laptop. So when they tried to access the data we sent back to them, it wasn’t recognised by the operating system on the Windows machine.

Ultimately here at R3 this is a rare occurrence. But it can happen from time to time. And when it does it isn’t ideal for either party concerned, as it generates more work and more time for things to be resolve. So something as simple as formatting a hard drive can have a big effect on jobs. Everything can go smoothly until the drive with the recovered media returns to the customer on a wrongly formatted disk. This is why formatting your hard drive correctly is important.

R3 Data Recovery is real lab that deals with real disasters each an every day. If you have RAID that has failed or any data storage device, we are the people to contact. Call us today on 0800 999 3282 for immediate help and assistance.

How To Identify RAID Devices

Synology RAID storage device

Modern storage devices come in many forms from simple USB devices that can be transported around in your pocket all the way up to network attached devices that sit next to your router or in your office accessible from your network or over the internet.

This is fine until you need data recovery and you are asked the question "is it a single hard drive or RAID device.." obviously this effects the cost of recovery.

Identifying these devices isn’t always straight forward but I hope this goes some way to explain the difference.

First of all there are a handful of vendors that regularly make multidisc RAID backup devices:

Buffalo, LaCie, NetGear and Gstore to name a few;

These devices can be large and have options on the rear of the unit for safe or large storage which is a giveaway that it’s a multidisc RAID device. The unit is heavy and bulky with lights on the front to indicate disc activity also may have the facility to remove the hard drives to upgrade the storage capacity in the future and also hints that it may be RAID.

Remember if all else fails just a simple Google search on the model will bring up the manufactures details and help guide you through some of the questions you may be asked by the data recovery company.

If we know this it can sometimes make the engineers lives easier as some manufacturers will tell you on their websites the parameters fo the model you may have. This could possibly save hours o time trying different parameters and configs and you could have your data back faster than you thought.

R3 Data Recovery is real lab that deals with real disasters each an every day. If you have RAID that has failed or any data storage device, we are the people to contact. Call us today on 0800 999 3282 for immediate help and assistance.

What Goes Into a Nand Read?

When a USB memory stick becomes unresponsive and a simple soldering iron repair doesn’t produce positive results then we have another recovery option called a nand read.

This method of recovery is very complex and involves several stages each very dependent on its proceeding stage.

Stage 1 is the removal of the nand chips. The number and style of nand chips varies with manufacturer, the chips must be unsoldered paying attention not to damage the delicate pins and then cleaned in an ultrasonic bath to remove flux residues.

Stage 2 is making dumps of the chip content. The data must be read from each nand chip, to be entered into software. This involves setting correct parameters for dump number, page sizes and any timings unique to the nand chip. This may have to be repeated if too many errors are detected at the end of the reading process and the settings tweaked.

Stage 3 involves reassembly of dumps. Once all the dumps are made they can be entered into software to start the long process of recreating what the microcontroller did when in charge on the USB device. Getting the data to line up within the dumps is a complex task involving a Xor pattern with many parameters to change that unfortunately isn’t automated. Once this process has been completed successfully the integrity of the data is checked and if good copied off... Stage 3 may have to be repeated several times to get good data.

If you'd like to learn more or speak directly with our engineers, please call us at 0800 999 3282

nand read

WannaCry Ransomware Attack - How To Recover Your Encrypted Files

During the recent publicity over the WannaCry ransomware attack I was in communication with a number of NHS clients who were asking how many enquiries were we getting.

The reality is the WannaCry ransomware attack was relatively insignificant other than the publicity it attracted and its interference with some services, not to downplay their impact but to put into perspective this attack was smaller in ransom value, ransoms paid and bigger in publicity possibly due to the state of the nation with regard to politics / manifestos / budgets and propaganda.

In terms of monetary value the ransoms were low. In terms of disruption to services it was not the Windows XP systems that were compromised it was the Win 7 and Server 2003 systems.

WannaCry ransomware attack

As a news item I was shocked at the publicity and panic mongering which seemed more politically motivated but I could be wrong, my observation is based on similar outbreaks in 2016 which knocked out entire cities and local authorities but were not publicised to the same extent.

We help the recovery process with ransomware decryption by first imaging drives sector by sector so that there is a second chance of recovery if anything goes wrong.

Don't forget encryption / decryption and malware / antivirus scanning can add extra risk to a storage device failing.

Get advice and assistance from Andy and the team at R3. R3 Data Recovery is real lab that deals with real disasters each an every day. If you have any sort of problem with a hard drive or any data storage device, we are the people to contact. Call us today on 0800 999 3282 for immediate help and assistance.

R3 are ICO registered and have been vetted by Hiscox Insurance for Cyberbreach and data disaster recovery claims assistance.

R3 is one of the few real data recovery labs in the UK and recognised by National Trading Standards forensics and NHS Trust Infrastructure managers as their data recovery rescue supplier.

R3 Data Recovery Ltd has imaging capacity onsite or in lab.

The lab can process imaging of upto 300TB per 24hrs in emergency situations.

We also can image factory / production computer system drives during shutdown periods to help with extending the life of SCADA / bespoke computer operating systems that are not networked or backed up.

R3 processed more successful recoveries of flood damaged ( submerged in effluent / flood water) drives in 2016 than any other british based data recovery lab.

R3 Data Recovery Ltd process Large scale IBM, HP, Dell, EMC, QNAP, Synology, RAID / SAN, VmWare HyperV and Drobo beyond RAID recoveries in Sheffield that our nearest competitors cannot undertake in the UK.

Dell RAID server recovery

All Hard Drives Fail

All mechanical devices eventually fail. It isn't a matter of how it is simply a matter of when.

On a side note though, solid state drives (SSD drives) are becoming more and more popular with computer users. First of all, they have become more affordable over recent years and their capacities have increased gradually. But ultimately SSD's have been highlighted as one of the most efficient ways to speed up your PC. Users love the speed increase in boot times and general performance whilst navigating your desktop.

It's also important to point out that solid state drives also fail. However, as it stands, and in the case of jobs we receive here at R3 Data Recovery, Mechanical hard drives still have the best opportunity of having their data recovered, and if looked after properly generally have more longevity to them.

Errors on hard drives

What Causes Errors On A Hard Drive?

From talking with our engineers at R3, an accepted cause of your hard drive failing is heat. Irrespective of how you feel about the role heat plays in wear and tear of the drive, you should take the approach of trying to limit the amount of heat your hard drive is exposed to, everyone knows the effect of heat on a PC's components, i.e. GPU, CPU, its only logical that it extends to your hard drive.

Physical damage of a hard drive can almost always leave it useless. In a brief explanation of the inner workings of a mechanical hard drive (HDD drive) it's basically made up of an aluminium platter that spins up once the device has power. The hard drive has a set of heads that accesses the data on the platter. As the platter spins, the heads move over it reading and writing data. Obviously by physically dropping your hard drive or dropping something onto it can cause the heads to become misaligned and by extension cause damage to the platter when they attempt to access to read/write from it.

Data recovery engineer

Hard Drive Clicking Sounds

A symptom of physical damage is a clicking sound once the drive is powered up. That particular noise you hear is the heads repetitively striking the platter which causes more and more damage and therefore makes the chances of recovery more difficult.

Furthermore, the age of a hard drive is also a significant aspect in regards to the health of the drive. Mechanical drives have many internal moving parts. These parts begin to breakdown over time, which causes the hard drive to degrade.

In most cases, the drive fails gradually. This is a clear advantage of having a mechanical hard drive. It will often start to show signs and symptoms that will give a preliminary warning to back up your data, not always of course but generally. In contrast to a mechanical hard drive, an SSD can often fail without warning. In addition, as we often find at R3 recovery from solid state drives is often complicated, and almost impossible in some situations.

How To Monitor Your Hard Drive

Awareness is essential when it comes to maintaining your hard drive. Amongst the most important of how long it takes to perform simple tasks. The first warning sign that the drive is starting to go degrade is the speed of data transfer becomes extremely slow. Your hard drive may be approaching the end of its life cycle if it takes an extended amount of time for you to transfer a small file.

As mentioned previously mechanical hard drives are made up of tiny moving parts. All of these parts move very rapidly in order to function. So obviously hearing out for unusual noises/vibrations and clicking is a sure-fire way of knowing your drive is failing or failed.

Another way of monitoring your hard drive is through software that tests for hard drive problems. Solid state drives and hard drives both have the capacity to use Self-Monitoring Analysis Reporting Technology (SMART) to test whether the memory storage equipment is functioning properly. Basically, by preforming a SMART test you can detect read errors, reallocated sectors, failing block count, wear and lifetime usage statistics that may be suggestive of significant issues. SMART hopefully will give you time to replace or recopy your data before the hard drive fails entirely.

Finally, and to reiterate, it's imperative to try as best as possible to keep the hard drive cool to extend its life cycle. People can take it for granted, but by purchasing and setting up a fan nearby to circulate the air around the unit may be very beneficial.

Ultimately, and what we here at R3 Data Recovery always encourage whether the outcome of recovery is positive or negative is that the best thing you can do is to back up your hard drive. It's the simplest and most cost-effective way of retaining your data as all hard drives eventually fail.

If your hard drive happens to fail, contact our team of experts at 0800 999 3282. Our skilled professionals will be able to reliably recover data on your hard drive and provide industry-leading turnaround times which give you the confidence that's necessary to develop a solid, effective recovery plan.

The Danger of Head Crashes

During the normal operation of a hard drive the delicate read/write heads float over the rotating media. The arm that holds these heads is shaped almost like an aircraft wing to provide this lift. This novel approach reduces the overall mass of the delicate assembly allowing higher transfer speeds but also because there isn’t contact between the two components then the life span of the hard drive is greatly improved.

Rings on a hard drive after head crash

The media used in modern hard drives is a Cobalt Alloy which is very soft so is protected by a thin layer only microns in depth of a lubricant that acts as a buffer if the heads ever were forced onto the media due to misuse of the hard drive.

This condition is referred to as a head crash, and the media will survive a number of these during its normal working life. However if this crash is severe enough that a scratch is created then the debris will be picked up by the heads and dragged around causing more damage and so the condition can quickly escalate into a huge problem.

It is important that when a hard drive has been abused and the data contained is very important that the hard drive isn’t powered.

The constant power cycling in desperate attempts to access this data can reduce the chances of a successful recovery and in extreme case render the hard drive beyond repair.

R3 Data Recovery is real lab that deals with real disasters each an every day. If you have any sort of problem with a hard drive or any data storage device, we are the people to contact. Call us today on 0800 999 3282 for immediate help and assistance.

What's a HDD - Basic Description Of A Mechanical Hard Drive

The Basics of Hard Drives

A hard disk drive is a computer device that allows data to be stored permanently. A hard drive (HDD), stores data even when it is powered down making it non-volatile, an example of volatile memory would be RAM which does lose data when it is powered down.

Parts Of The Hard Disk Drive

  • ​​​​Read/write head(s) - Just as the name suggests the heads are the physical part of the disk that writes data to the platter surface, reads the data already written to the platters or deletes the data on the platters.
  • Actuator arm - The actuator arm is the part of the disk which holds the read write heads.
  • Case/chassis - The chassis is the metal casing which contains all the internal parts of the disk as well and holding the external circuit board.
  • Spindle - For mechanical hard disks the spindle holds the platters and allows them to spin at high speed.
  • Platter(s) - The platters are the disks contained within the hard disk normally made using aluminium or in some cases glass that contains a ferrous surface which holds magnetic charge which is how the data is stored on them.
  • Circuit board - A printed circuit board which contains chips and other electronic components which control the hard drive as well as the interface that connects it to a computer.

How Do They Save Data?

Data is written to a hard disk in the form if a magnetic signal in the surface of the platters, platters are broken down to specific areas.

How Does It Connect To The Computer?

Hard drives connect to a computer using a bus through an interface most often IDE or SATA although there are other interfaces such as SCSI and Fibre Channel.

R3 Data Recovery is real lab that deals with real disasters each an every day. If you have any sort of problem with a hard drive or any data storage device, we are the people to contact. Call us today on 0800 999 3282 for immediate help and assistance.

What's A Monolith?

This is a term used to describe a method of construction that encapsulates the electronic components in resin during manufacture; this resin then solidifies to form a solid in-assessable plastic block with just the gold connections visible.

This provides a barrier from dust and moisture and protects the delicate electronics but also provide a more robust device to make the casing thinner and therefore cheaper to manufacture.

The usual techniques used for recovery become severely reduced with very few cheap recovery options available.

R3 Monolith