Month: October 2019

Many customers ask us if enterprise class SSDs are more reliable than consumer ones. In a nutshell, yes enterprise SSDs are more robust. However, enterprise class still disks such as the Samsung PM963, PM853T, SM843 and SM863 still fail and need data recovery.

However, there are a number of reasons why enterprise-level SSDs are more reliable than consumer-level disks.

• Most enterprise SSDs tend to use controllers which employ smarter ECC engines. For example, some enterprise SSDs come with 24-Bit ECC along with CRC. This is very useful for minimising data corruption.
• Most enterprise SSDs employ over-provisioning, which means the inclusion of extra or “spare” blocks to increase endurance.
• Most enterprise SSDs often use an SDRAM cache for a more efficient handling of metadata.

There is another class of SSD which most people forget about and that’s industrial-class SSDs. These tend to be even more robust than enterprise-class models. For example, in the event of a sudden power loss, some industrial-class SSDs use special capacitors which provide enough energy for the SSD controller to finish any operations that are currently being processed. Some industrial SSD manufacturers, like Innodisk, take power loss protection even further by using a “low-power detector” in their disks, which triggers a recovery algorithm (iData) that assists the drive in shutting down gracefully while also preventing data loss and ensuring data integrity. In the event of corrupt data getting written to the disk, table-re mapping is deployed to delete it. Moreover, most industrial-class SSDs have much more resilience to temperature extremes, which is very useful if you are deploying an SSD in a cold store or smelting plant…

Drive Rescue are based in Dublin Ireland. We offer a full SSD recovery service for disks such as the Samsung PM963, Intel S3510, S3520 and San Disk X100, X400 and X600.

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LaCie external hard disks have always been extremely popular with Apple Mac users in Ireland. Most of their models of external disk tend to be high capacity and come equipped with Thunderbolt 2 or Thunderbolt 3 ports. Their “Rugged” range of external disks (such as Rugged Mini, Rugged Thunderbolt and Rugged Triple) uses Thunderbolt or USB-C ports. Disks in the “Rugged” range are swaddled in a distinctive orange rubberised overcoat to protect against shock damage

LaCie also offers a range of DAS RAID devices such as their 2Big, 2Big Quarda, 2Big Dock Thunderbolt 3, 4Big, 5Big and 8Big devices which offer high capacity local storage without having to use USB or LAN connections.

And LaCie is perhaps the only hard disk manufacturer to have introduced a range of “designer” external hard disks allegedly based on designs by the Porsche design studio in Germany.

While most users have a trouble-free experience. Unfortunately, some LaCie owners can experience data inaccessibility problems with their disks. These include:

• Accidental deletion of HFS+, APFS formatted LaCie disk
• Accidental deletion of HFS+, APFS or NTFS partition
• Accidental shock damage (e.g. dropping your LaCie disk)
• Power surge damage to your LaCie disk
• LaCie disk with corrupted firmware

Such issues can manifest themselves in various ways, such as:

• Your LaCie disk is not recognised by macOS when connected to your iMac or MacBook.
• Your LaCie disk no longer spins ups.
• Your LaCie disk is making a beeping, ticking or a clicking noise.

Such a case happened only last week to a user in Mayo. They used a D2 Thunderbolt disk in their media production business for many years without incident. However, recently they connected the disk to the Mac computer and it was not recognised. Their local IT support company ran data recovery software which could not even recognise the disk let alone find any data. They sent the disk to us. We opened up the case and found a 4TB S-ATA Seagate IronWolf disk. (This was not really surprising as Seagate now owns the LaCie brand). Our diagnostics revealed 2 weak disk-heads. This explained why the disk was not being recognised. One of these heads was needed to read the Master Boot Record of the disk but couldn’t. In our class-100 cleanroom, we removed the old Head Disk Assembly (HDA) using a customised “head-comb” for Seagate Ironwolf disks. We replaced it with a new HDA. Due to the architecture of IronWolf disks, inter-head alignment (getting all disk heads aligned with each other) was time-consuming (but very important in order to minimise NRRO – non-repeatable run out errors). We then slowly imaged the disk overnight. (Trying to operate a disk which has undergone a “head transplant” at full speed can lead to the new disk-heads getting rejected) The following morning, we were able to initialise the disk but, to our dismay, still no HFS+ volume was showing. Further diagnostics, revealed that the file system just needed some repairing (this can happen occasionally after an HDA swap). After repairs to the file system had completed, we finally got the volume to mount successfully. All files were appeared intact and the volume even retained its “LACIE” name – always a good sign after recovery!     

Adobe Lightroom, MPEG, AVI files, and FCPX (Apple Final Cut Pro) files were all successfully recovered, saving our customer hours and hours of redoing work. He was now able to get on with his workflow with minimal disruption as if nothing had happened.

Drive Rescue offer a full data recovery service for LaCie D2 disks, LaCie Rugged, LaCie Big (RAID) and LaCie Porsche Design USB disks in Dublin, Ireland. LaCie Data Recovery in Ireland Call us on 1890 571 571

Many IT admins contact us in a state of disbelief after discovering multiple cascading disk failures during a RAID rebuild. Why does this happen? Well, when you rebuild a RAID, every sector of each disk is read. The rebuild process is the equivalent of an Ironman challenge for your disks. This can make silent disk failures all manifest at once. It’s not that disks actually fail during RAID rebuilds (although this can happen), it just that when every sector of a disk is read, the failure threshold gets tipped. You can help mitigate against this by using disk rotation and employing hot spares on your array.

Avoiding the “bad batch” problem

Cascading disk failure is not the only problem that affects RAID. Another one is the so-called bad-batch problem, which can lead to near-simultaneous failure of RAID arrays. This can occur if there is a flaw in the manufacturing process or a design flaw in the disk. This flaw is then replicated in all of the disks from the same batch. If the flaw is serious enough it can result in near-simultaneous disk failures of multiple disks in your array. Some IT administrators procure the same type of disk from different vendors in order to avoid this problem, which can work. However, some RAID controllers don’t play well with different firmware versions, as is often found on disks procured from different batches. This can introduce a brand new set of headaches.

The one parity scheme, as used on RAID 5

Why RAID 5 is now (almost) redundant?

RAID 5 was fine back in the day when arrays of smaller capacity disks were commonplace (like 250GB X 4). Now, with larger disks (2TB, 6TB etc.), the probability of a failed read during a RAID rebuild process becomes too high. During a rebuild, every sector has to be read. If there are any errors on a second disk, the rebuild will halt. With arrays containing individual disks of 2TB+ that is a big ask and makes RAID 5 unsuitable for most modern IT environments.

Two independent parity schemes, as used on RAID 5

RAID 6 to the rescue

Enter RAID 6. This type of array uses two independent parity schemes. So even if one particular disk develops unreadable sectors, there is a second parity strip and your RAID rebuild should complete successfully.  

Drive Rescue are based in Dublin, Ireland. We offer a complete RAID 0, 5, 6, 10 data recovery service for HP Proliant, Dell PowerEdge, Fujitsu Primergy servers. We also offer a NAS data recovery service for Synology, ReadyNAS and QNAP devices.