A Longford-based customer recently sent a 1TB Seagate Backup Plus disk for data recovery. When connected to a Windows PC, the following error message was displaying:
D:\ is not accessible
Data error (cyclic redundancy check)
Cyclic Redundancy Check is a mathematical equation used to ensure the integrity of data. It works by multiplying the number of bits in the data packet by a pre-determined number prior to data transmission and retains the answer. Once the data is received, it executes the same equation again. If the two answers match, your computer processor knows the data is intact. CRC checking is commonly used in TCP/IP networking but is also in disk-to-disk communication such as when an external hard disk or USB memory device is connected to a computer.
Fix Cyclical Redundancy Check errors
Typically, the Cyclic Redundancy Check error message tells us there is a problem with a storage device. In a small minority of cases, the issue can be resolved by running the Checkdisk (Chkdsk) command on the disk within Windows. However, in the vast majority of cases the Cyclic Redundancy Check error message is indicative of a more serious problem with a disk.
In this particular case the client’s Seagate Backup Plus disk had over 20,000 uncorrectiable bad sectors. We used our specialised data recovery equipment to “read around” these sectors and then performed a “read retry” operation on them. Our equipment does this at a very low level, meaning we can access data which would be otherwise unreadable to operating systems such as Windows, OS X or Linux.
We were successful in recovering all the file types needed by the client. These included .docx, .xlsx and .mdf (Microsoft Access) files. Case was closed with one extremely satisfied customer!
Drive Rescue Data Recovery Dublin offer a complete data recovery service for external hard disk drives such as Seagate Backup Plus, WD My Passport, MyPassport Ultra, Freecom Toughdrive, Maxtor M3, Toshiba Canvio, Transcend and Verbatim. To find out more visit: www.datarecoverydublin.ie
We recently recovered data from a QNAP TS-253 Pro. This is a popular two-bay NAS device which uses the QTS operating system. This particular NAS was using two WD Purple (WD20PURX) S-ATA disks formatted with EXT4. Even though the device was set up in a RAID 1 configuration – it experienced an event which corrupted the firmware of both disks. The problem was surmountable as we recovered 100% of the client’s data, but this case presents a number of important lessons in secure data management.
Why using WD Purple are not a good idea for general data storage
The roots of the problem go back to when the device was first set-up. Their IT administrator chose two WD purple disks. These 5400 RPM disks are primarily designed for use with NVRs (network video recorders) and DVR (digital video recorders). The firmware in them is optimised for constant ATA streaming of contiguous data. It is not really designed for the kind of random reads and writes as you would expect in an administrative office. Moreover, the error correction algorithms used in these disks are tuned for speed with data integrity taking a back seat. It is really not surprising then that just after a couple of months usage – the data on the volume became inaccessible. And of course, Murphy’s Law kicked in with both disks failing simultaneously.
How this data loss situation could have been averted.
Ideally, the client should have been using WD Red disks (or other disks designed for NAS) to prevent this problem from occurring. And of course, they should have been backing up their QNAP. A NAS (even configured in RAID 1) is not a backup in itself. They should have been using an app such as Duplicati backing up an off-site server such as S3 or B2.
As virtualisation becomes more prevalent, it’s nice to have some VHD recovery tools in your arsenal. One great tool that we can recommend is Hyper-V Recovery from SysTools. If you have a VHD which has become corrupted or inaccessible, give it some tender loving care with Hyper-V Recovery. It uses smart algorithms bundled with an intuitive interface to repair the dynamic and static VHD files on FAT and NTFS.
A customer recently delivered a Lenovo Thinkpad X1 to us for data recovery. When the system would start, the error message “a disk read error occurred” would appear on the screen. The POST process will halt at this point.
We opened up the system and found a proprietary SSD made by SanDisk (SD5SG2-256G) using a form factor of (70mm x 20mm) and a 20+6 connector pin. Proprietary SSD form factors and connectors were common in the early days of mass SSD deployment in laptops and tablets as device manufacturers raced to make their devices as thin and light as possible.
The SanDisk SSD recovery process.
We put the drive into “technological mode”. This is the same mode SSD manufacturers use to perform disk repair and diagnostics. Then using a custom-adaptor for this SSD we connected it to our firmware emulator and uploaded a Marvell 88SS9174 firmware module. The Windows 10 and recovery partition appeared but was still not readable. However, adjusting read parameters on our equipment (which dynamically adjusts voltages used to read NAND cells), we able to access the volume in full. All the customer’s Word, Excel, Calc and Quantrix were successfully recovered onto a USB external disk.
On the 29th of December 1972 Eastern Airlines flight 401 takes off from a bitterly cold New York en route to Miami. 163 passengers are on board, most of them hoping to celebrate the New Year in the sun. Approaching Miami the pilot presses the button to activate the landing gear. Normally, a green light illuminating in the cockpit indicates successful deployment. However, in this case, no green light illuminates. The crew removes the bulb and blow on it to remove any dust. They screw it back tightly. Meanwhile, they fail to notice that the autopilot has become disengaged and the aircraft is now losing altitude. However, the crew is so fixated on fixing the bulb they fail to notice the rapid descent of the aircraft. Being night time, they have little visual cues. Their aircraft stalls and hits the ground. Only 75 of the 163 passengers survive the crash.
Fast forward to 2009, Air France flight 447 leaves Rio bound for Paris. Just three hours into the flight, the aircraft’s pitot tubes (used to detect airspeed) malfunction. This causes the autopilot to disengage. The cockpit becomes a cacophony of sirens and alarms. The pilots fixate on raising the plane’s nose when they should have been lowering it. The aircraft stalls. Tragically, according to aviation experts, the type of stall their aircraft experienced was recoverable from. However, the pilots were so fixated on raising the plane’s nose – they fail to recover the aircraft from its stall and it plunges into the South Atlantic.
Problem Fixation and IT Troubleshooting
These two cases illustrate how problem fixation can sometimes have tragic consequences. You might be thinking how does this relate to data loss? Well, unfortunately, problem fixation is also an issue in the world of information technology. Hard disk failure provides a classic example of this. When a disk is failing, some end-users and sys admins can easily mistake the symptoms of a failing disk with another un-related problem. This is understandable because symptoms of a failing disk will often manifest themselves in unexpected ways. For example, a failing disk can cause an operating system such as OS X or Windows to throw up all sorts of spurious error messages. This can lead to some frantic googling of symptoms which have little or no relation to the real problem. Likewise, the symptoms of a failing hard disk can often mirror those of failing hardware components such as RAM or graphics cards. And then of course, there is the issue of viruses and malware – the symptoms of which also closely resemble those of a failing disk. Applications may fail to start or run painfully slow. Some users will perform virus and malware scans in their efforts to remove a non-existent infection. The potential for problem fixation does not end there though. When a failing external hard disk is connected to an operating system spurious error messages like “Data Error – Cyclic Redundancy Check” (Windows) or “you need to format the disk in drive E: before you can use it. Do you want to format it?” (Windows) can be thrown up. As for NAS devices, these can be a veritable Pandora’s box of cryptic error messages which users can end up fixating on. Take for example, Buffalo’s error coding system which begins with “E”. You might get an ”E13” message or “E14” “E15”, “E16” “E22” “E23”or “E30”. All of which might look like something written on the back of a packet of Skittles but are all basically reporting the same thing “there is something seriously wrong with one of your disks”. However, if a user goes down the Google rabbit hole with these error messages – valuable time can be lost, all while a disk’s condition might be deteriorating rapidly.
Don’t Fixate on Error Messages or Symptoms
The philopsher William of Ockham (of Ockham’s Razor fame) once said “With all things being equal, the simplest explanation tends to be the right one”. And there is some truth to this. If a computer system or storage device is acting strangely – sometimes going back to basics is a worthwhile strategy. Start off with performing disk diagnostics first to find out whether the disk(s) are healthy or not. But fixating on particular error messages wastes valuable time especially when the underlying problem might be a failing disk. Finding this out quickly affords you the opportunity to perform a complete disk backup and possibly negating the need for a data recovery service!
Drive Rescue Data recovery is based in Dublin, Ireland. We recover from portable hard disks (LaCie, Seagate, Toshiba, WD), laptop and desktop disks (HGST, Seagate, WD). We also offer a data recovery service for SSD disks (including Micron, SanDisk, Crucial), DAS devices (Lacie and G-Tech) and NAS devices (Buffalo, Synology and ReadyNAS). Phone us on 1890 571 571 www.datarecoverydublin.ie
Drive Rescue normally performs data recovery from physical storage devices such as hard disks, SSDs, USB, memory cards, servers and NAS devices. But last week, a customer from an island off the west coast of Ireland called us desperately wanting to know how to recover deleted emails from their Gmail (for business /GSuite account). Thankfully, Gmail stores deleted emails for the last 30 days. Moreover, the data recovery process for this is a cinch.
To recover deleted emails from Gmail (GSuite Edition) is relatively painless.
1) Login to the account needing recovery at: admin.google.com
2) Click on More
3) Click on Restore Data
4) Select the Data Range (remember 30 days is the maximum amount of time you can wind back to)
5) Select the application. Google Drive is the pre-selected as the default, but using the drop-down arrow, you can select Gmail.
6) Click on Restore.
7) Your deleted emails from the last 30 days should now be recovered.
The same more process can be followed for recovering data deleted from Google Drive. You just select “Drive” instead of Gmail. Easy peasy!
Accurate hard disk monitoring and diagnostic tools are an essential part of every IT admins toolbox. So, we’ve put together a short list of hard disk monitoring and testing tools along with some best practice tips on their operation.
Hard Disk Monitoring and Diagnostic Tools 2018
Hard Disk Sentinel – nice simple monitoring tool which indicates disk health and temperature.
HDDLife – another reasonably accurate hard disk monitoring tool. Also comes in an SSD variety (SSDLife).
CrystalDiskInfo – Fantastic benchmarking tool which indicates sector reallocation count and un-correctable sector count.
HD Tune – Offers a nice graphical representation of disk performance and scans for errors. Supports SSDs like OCZ and Samsung.
Computer manufacturers like Dell and Lenovo offer their own built-in disk diagnostic tools. The latter offers their Lenovo Solution Center tools while Dell offers their Pre-Boot System Assessment. Both do a reasonable job of testing mechanical hard disks.
Testing a Seagate, WD or HGST hard disk using manufacturer utilities.
The disk manufactures themselves also offer diagnostic tools like SeaTools (Seagate) and WD Lifeguard (Western Digital). HGST offer their Windows Drive Fitness Test (WinDFT). For some reason, Toshiba offer no disk diagnostic tools at all!
Testing an Apple Mac hard disk
There is a huge paucity of accurate disk monitoring or testing tools for Apple’s OS X. Many end-users erroneously believe that the “First Aid” utility provided by Disk Utility can check the health of a disk – it does not! It just checks the integrity of the file system.
If you need to test the hard disk in an Apple Mac, we highly recommend SMART Utility from Volitans Software which really stands out from the pack for its accuracy and reliability
Solid State Disks are different…
Because SSDs are designed using manufacturer-specific schemas, for best accuracy you really need to download their own diagnostic utilities. Most of these can be found on the relevant manufacturers’ website.
SanDisk – SanDisk SSD Dashboard
Samsung – Magician
Crucial – Crucial Storage Executive
Best Practice Tips on running Accurate Hard Disk Tests
1) If your hard disk diagnostic test halts half-way through and appears to have frozen. This can be indicative of a defective hard disk.
2) It is important to remember that a hard disk diagnostic test will not always detect early stage failure. This is because most diagnostic utilities only randomly scan certain sectors of the disk. Even a long-diagnostic test might “pass” a disk in the early stages of failure. This is because under most jurisdictions, manufacturers are obliged to offer an RMA policy (return merchandise authorisation) and most have set quite a high threshold for a disk to be deemed “failed”.
3) Most firmware issues will not be detected by hard disk diagnostic utilities.
4) If you suspect software, malware or OS issues are interfering with the accuracy of the test, slave the disk to another system (using a direct M.2 / NGFF/ mSATA / S-ATA / P-ATA connection to the system’s motherboard or just use a USB dock) Alternatively, you can use a bootable ISO containing hard disk diagnostic utilities.
5) Remember that some bootable diagnostics such as Seagate’s SeaTools for Dos will only run if the system’s BIOS/UEFI is in IDE mode (as opposed to AHCI mode)
We helped a customer last week who believed that his data was being safely backed up to his Apple iCloud drive when in fact his Mac was performing a phantom backup.
Let me explain. Our customer discovered that the 2.5” hard disk (HGST Z5K-500) inside his MacBook Pro had failed. Believing that iCloud had his back covered, he logged into his iCloud Drive and reassuringly saw the whole folder structure of his failed disk. But to his horror, when he clicked on these folders most of them were empty. The folders were there, but the files were not at home… It transpired that iCloud, whilst giving the impression of a complete disk sync had just synced the folder structure of his disk.
Stored on his iCloud account were – what only can be described – as “Phantom Backups”, empty shell folders created by the iCloud application, which merely gave the illusion of backup. And this is a surprisingly common problem.
The Cause of Phantom Backups
There are a number of reasons why phantom backups get created. First of all, from a software development perspective, online syncing or back-up from an endpoint device such as a laptop to a remote (cloud) server is actually quite a delicate process. The backup or syncing application must get deep support from the operating system to function. It must then replicate the folder structure of the source disk. Then, it must transfer data using data packets of a reasonable size. Then, the app must decide correctly, which files have changed since the last sync or backup. This whole process is dependent on a good quality, stable internet connection with a reasonable upload speed. And for the whole process to complete successfully – it is preferable that the user does not max out their upstream bandwidth by simultaneously uploading boxsets onto P2P sites, letting their battery run flat or turning off their system mid-sync. So, that’s a lot of boxes to be ticked.
Don’t get fooled by a Data Mirages
However, even if this process fails a user can still log in to their iCloud, One Drive, Amazon Drive etc. account and will probably see what looks like a backup of their files. On the surface, the folder structure will all be there which looks very reassuring. But, like a parched trekker in the the desert discovering that the apparent spring ahead of them is a mirage, discovering after a data loss event, empty folders on a cloud server can be just as gut-wrenching.
How do Phantom Backups Happen?
Well, one of the first functions an online sync or backup app will perform will be the re-creation of the folder structure as selected by the user. This might be just a few folders and sometimes it can be a whole disk. Once the folder structure is in place, the application will try to populate these folders with data. But here’s the rub, even if something does go askew during this process, the whole folder structure will appear to the user anyway, even if it is just a pile of shell folders.
Preventing Phantom Backups
The importance of backup verification cannot be stressed enough. Dropbox does this very well. They use a tiny green dot above the folder on the source device to indicate a successful sync. Other backup providers use less slick means like sending the user an email confirmation of backup which is nice but unless it has a complete file listing could be misleading. And of course, there is always the manual “eyeball” verification method where the user can physically log in to the cloud server and inspect their files. And more importantly, using this strategy the user should pick folders at random, drilling down while checking for file completeness and integrity.
It could be construed from this blog post that syncing is a form of backup – it’s not. Yes, it’s better than nothing, but if you’re using a syncing application as a sole backup means – it really needs to be complemented with another (preferably) isolated backup medium. Remember syncing applications can be pretty lousy at protecting your data from sabotage, ransomware or accidental deletion. But that topic alone merits another blog post.
Drive Rescue Data Recovery is based in Dublin, Ireland. We offer an Apple data recovery service for MacBook, MacBook Pro, MacBook Air and Mac Mini devices along with iMacs. Find out more at: www.datarecoverydublin.ie
Last week Drive Rescue was in Nuremburg, Germany for Embedded World 2018. The Embedded World exhibition and conference covers a lot of areas including IoT, defence, aviation, automotive and industrial electronics. It is also one of the largest gatherings of global hard disk manufacturers in Europe, where they display their wares and discuss their future roadmaps. It was fascinating to see the latest in the world of storage devices and interesting to speak to the hard disk manufacturers’ first hand.
A number of themes emerged at this year’s exhibition and conference, including the focus which disk manufacturers are placing on data security (no doubt spurred by the impending GDPR legislation) and the emergence of SSD technology as de facto standard for many industrial and consumer-level devices.
Disk Manufacturers taking the GDPR to Heart
Disk manufacturers, especially European-based ones, seemed to have taken GDPR legislation to heart with companies such as Integral (UK) and SwissBit (Switzerland) now offering an extensive range of SSD disks and USB memory devices equipped with hardware-level AES encryption. For example, Swissbit have now introduced a USB memory stick (PU-50n DP) which uses native AES-256 encryption and which is also capable of storing an audit trail. It’s audit trail functionality is enabled by storing WORM (Write Once Read Multiple) data on a cleverly located hidden partition. To counter any brute-force hacking attempts, the PU-50n DP comes equipped with a hardware retry counter which limits the number of passwords which can be inputted within a set time frame.
Integral also displayed a range of AES-256 encrypted USB memory drives which are FIPS 140-2 approved and employ a dual-password system. So, if the user does forget their password, their IT administrator can regain access using a master password. But, pity the poor user who does decides to go it alone, because only after six failed access attempts the data and the encryption keys are all destroyed. Crikey, only step away from the device spontaneously combusting…
Integral were also displaying their range of AES-256 “Crypto” SSDs. Like their USB drives, they are FIPS 140-2 approved and if the number of password attempts is exceeded the encryption keys and data gets destroyed. A “high strength” 8-16 character alphanumeric password must be set which presumably precludes users inputting “PaSSwoRd” or “fluffy123” as their password. According to the Integral marketing bumf, their encryption is compatible with most endpoint security applications as it uses a configurable “hardware ID” for compatibility. In the next couple of months, it will be interesting to see if hardware SSD encryption schemes such as this pose a challenge to the hegemony of McAfee, Symantec, Sophos et al in the full disk encryption arena.
And speaking of McAfee, Hagiwara Solutions (Japan) have brought out this AES-256 encrypted USB stick which also contains anti-virus detection powered by McAfee software. Virus propagation prevention and encryption all in the same package!
The Last Hurrah of S-ATA
The venerable S-ATA bus interface has served the IT world exceedingly well over the last fifteen years. It liberated many an IT administrator from the tyranny of jumper settings and compared to its P-ATA predecessor, introduced a seismic leap in faster I/O disk operations. But even though S-ATA has progressed to its third iteration (SATA 3.0), for most solid-state disks, this bus standard and its command protocol AHCI has now become a data bottleneck. For example, most NVMe solid-state disks can handle 65536 parallel I/O requests compared with only 32 I/O requests processible by S-ATA 3.0.
And while S-ATA III and AHCI will probably be around for legacy applications for quite some time yet, its days of being the primary interface for internal storage devices are probably numbered. So, if S-ATA is on the way out, what is going to replace it? Enter PCIe and NVMe.
All aboard the NVMe bus
NVMe (Non-Volatile Memory) is a protocol designed by a consortium of hard disk and NAND manufacturers including Western Digital, Samsung, Toshiba, Intel and Micron to standardise the interface and interoperability of PCIe. In essence, the NVMe standard allows disk manufacturers fully exploit the parallelism afforded by PCIe when interfacing with host systems. Operating systems need only one driver for NVMe compatibility. This driver has been included in Windows OS, from version 8.1 upwards and in Apple’s OSX from version 10.10.3 (Yosemite).
The rise of the M.2 Form Factor
There were plenty of SSD disks at Embedded World 2018 still using variants of the S-ATA connector such as mSATA (52pins split into 16 pin and 36 pin sections) and Slim SATA (22 pins standard S-ATA connector). However, the M.2 form factor (pronounced m dot two) was by far the most common on display. The first generation of this form factor came in the guise of NGFF (Next Generation Form Factor) which is rarely seen these days. The present-day M.2 form factor uses three socket types including; “B key” edge connector, “M key” edge connector and “B and M” key connector. A “B key” uses up to two PCIe lanes whereas an “M key” can use up to four. A substantial number of SSDs use the “B and M” key connector so they can connect to any socket. Each connector pin is rated for 50V and 0.5A. Using PCIe x4 the M.2 standard allows for blisteringly fast data throughput speeds of up to 31.5Gb/s compared to 4.8Gb/s offered by SATA 3.0.
It might be easy to dismiss the NVMe standard as just a marketing gimmick. After all, it is designed using PCIe architecture. But, the designers of this protocol appeared to have gone to great lengths to eke out every ounce of SSD I/O speed when interfacing with its host. The real-world throughput difference between an M.2 disk using PCIe x4 and MLC NAND using NVMe versus an M.2 disk of similar specification not using NVMe can be vast.
Goodbye SLC and hello pSLC
Pure SLC NAND was harder to find than hens teeth at Embedded World 2018. This is because it’s ten times more expensive to manufacture than MLC and many producers are unwilling to tie up their expensive fab (semiconductor fabrication) facilities for this niche product. So even industrial-class SSD manufacturers like Innodisk are now using pSLC (pseudo-SLC) as a happy medium between the reliability of SLC and the production costs of MLC. Pseudo-SLC (otherwise known as MLC+) uses MLC NAND but the memory cells are used in single-bit mode. Moreover, the voltage threshold is shifted for increased endurance, reduced error rates and better SSD longevity.
From 2D NAND to 3D NAND
Up until now, most SSD manufacturers have been using planar NAND. Typically, MLC (Multiple Level Cell) stores two bits-per-cell while TLC (Triple Level Cell) stores three bits-per cell. But the quantum physics envelope can only be pushed so far. As die lithographies reduce in size to 19nm,15nm and 14nm issues like cell-to-cell interference and disturbance effects start to kick in. This results in un-correctable bit errors which even sophisticated ECC algorithms such as BCH or LDPC cannot fix. This results in lost or corrupted data. So NAND developers have responded by stacking their cells on top of each other instead of laying them out vertically. This is analogous to building a skyscraper instead of a building which extends over a wide surface area. Samsung were one of the first manufacturers to commercialise this type of NAND and named it “3D NAND”. Other manufacturers like SanDisk/WD, Crucial, Intel and Adata have followed suit. Today the widespread adoption of 3D NAND has been aided by controller designers like Phison and Silicon Motion. The latter having recently released their SM2262 PCIe 3.1 NVMe 1.3 compatible controller designed to work optimally with 64-layer 3D NAND. And Phison have recently released their PS5007-E7 controller optimised for 3D NAND and NVMe.
3D NAND – the floating gate versus charge trap debate
While most SSD manufacturers share the consensus that 3D NAND is the best fit for consumer and enterprise-class disks. After this, however, agreement diverges. 3D NAND can be deployed using floating gate or charge trap transistors. Floating gate transistors use polycrystalline silicon whilst charge trap transistors use silicon nitride. Floating gate transistors have been around the 1970’s. Now remember the purpose of the transistor is to “trap” electrons. To put it in very simple terms, silicon nitride is like cheese, whereas polycrystalline is like water. Some NAND designers believe that electrons “leaking” is a problem with floating gate technology, whereas using charge trap transistors electrons are more likely to be held in place. Thus, your data might have more longevity when stored with 3D NAND using charge trap transistors. Intel is placing their bets on floating gates. Samsung, with their V-NAND technology and Toshiba with their BiCS technology are backing charge trap transistors.
Of course, Intel have got some critics in their choice of technology, namely – why are they deploying 1970’s technology for their 3D NAND solid state disks when an apparently “better” transistor design exists? Well, Intel say they are using “discretised floating gates” which they claim are more compartmentalised and better suited to preventing electron leakage. They also claim that floating gate transistors are a “tried and tested” technology, whereas charge trap flash transistors are not. It will be interesting to see the trajectory of 3D NAND over the coming months.
Drive Rescue Data Recovery are based in Dublin, Ireland. We offer a data recovery service for most SSD disks including Samsung (750 Evo, 850 Evo, 860 Evo, MZ7TY256HDHP, MZNTY256HDHP, PM841, PM851) SanDisk (SSD Plus, Ultra II, Ultra III, X110, X400), Apacer (AST 280, AS220), Crucial (MX200, MX300,MX500, M500,M550) Kingston SSD, Toshiba SSD (Q200, Q300), Toshiba Apple SSD and Intel SSD (320, 530, 540S, S3520, S3700, S4500, S4600) For more information: www.datarecoverydublin.ie Phone : 1890 571 571
While better known for their flash memory devices, the Taiwanese company storage company Transcend also makes a limited range of 2.5” external hard disks. Typically, they use Samsung Momentus disks – in 500GB (ST500LM012) or 1TB (ST1000LM024) sizes. As mechanical hard disks go, these are fairly robust models. Their head disk assembly is tried-and-tested and they use fairly stable firmware.
So, what could possibly go wrong? Well, there is the perennial problem of users dropping their disks. Often, accidentally dropped disks don’t happen out of carelessness just unexpected events. Like, for example, a customer who delivered a disk into our office recently. On his commute home, he had his Transcend external hard disk attached connected to his MacBook Air. He was seated in an aisle seat. His fellow passenger in the window seat had dozed off. As the train was pulling into one of the stations his neighbouring traveller suddenly woke up, looked out the window and discovered to his horror that it was his stop. Our customer, being a gentleman, MacBook-Air-in-hand quickly jumped up from his seat only to suddenly hear the clatter of an object fall onto the aisle of the carriage. It was his external hard disk. His fellow traveller alighted successfully from the train. Our customer gingerly went back to his seat to re-connect the disk only to hear it clicking.
Luckily, only one disk head was damaged, but the head disk assembly still needed to be replaced in our clean-room. The platters had escaped damage. We were able to achieve a 99.5% recovery rate salvaging all of his PPJ (Adobe Premiere) files.
How to prevent this happening? Well, if you plug out an external disk quickly from an OS X (Apple) operating system without going through the “eject” procedure – you risk corrupting the “catalog” file of HFS+ (the file system) which can also lead to data loss. Or, you could use a “wireless hard disk” but I dread to think of the security implications of these especially when used in public places. So, it all goes back to having a robust back-up plan. Or, maybe just not sitting on an aisle seat on a train…
Drive Rescue Data Recovery are based in Dublin, Ireland. We recover data from all brands of dropped external hard disk including Transcend, Adata, Toshiba, Seagate and WD. Phone 1890 571 571 www.datarecoverydublin.ie