RAID 5 HP Smart Array E200i Recovered

Smart Array E200i SaS Drive
HP Smart Array E200i SaS Drive

We have just competed a successful recovery from an HP Smart Array E200i RAID array. Not a standard case this. It had x3 DG146BB976 2.5″ SaS drives, two of which had been overwritten with a new RAID 1 mirror.

We found the disk order which was not the same as the labelled numbers. This is often the case. Also, due to the rebuild that had occurred we had to drop one of the disks and virtually rebuild it using the parity information from the other disks.

3 DG146BB976 SaS ST9146802SS Drives
3 DG146BB976 / ST9146802SS SaS Drives

4K Sectors & RAID

ZDNet has an interesting article about 4K sectors (Advanced Format), however what was more interesting was the bit about large SATA drives.

 Today’s large SATA drives shouldn’t be used in 4 drive RAID 5 arrays due to the high likelihood of a read error after a drive failure, which will abort the RAID rebuild.

It is a common misconception that if you run a RAID system then you can avoid keeping backups. Although fault tolerant to a point, there are plenty of issues with RAIDs that can at best cause lengthy downtime and at worst prevent any recovery at all.

More info on RAID Recovery

Hitachi 1TB Platters

The Register reports that Hitachi have beaten Seagate to market with 1TB per platter drives. These will apparently pave the way for 4TB drives, however are currently limited to single platter options up to 1TB. I hope nobody tries to make a RAID 5 with a bunch of 4TB DRIVES. That would be asking for trouble.

Read more on The Register

LaCie 5Big RAID 6 Recovery

I will start by saying that we can, and have, recovered data from these drives. As with all RAID recovery we carry out, we never use the original controller or drives to access the data. We image the drives on an individual basis and then work on these drives to rebuild the RAID using a form of RAID emulation. The most time consuming part of this type of recovery is discovering the RAID settings that the manufacturer has used.

Due to the complex nature of these NAS devices, we always recommend they are backed up to another form of media. Although recovery is possible, it can be expensive and relatively time consuming. Also if the unit is powered on and RAID rebuilds are attempted then the recovery can be made more complicated or even impossible.

A Little Background

The LaCie 5Big NAS device contains five hard drives and allows for a number of different configurations. One of these configurations is RAID 6, which works in much the same way as RAID 5, but with an additional parity stripe. This additional parity stripe uses an algorithm which requires a relatively high processing overhead, so RAID 6 has rarely been seen in consumer level devices. The low cost of processing means that RAID 6 is now a viable option for embedded NAS devices such as the LaCie 5Big.

The advantage of RAID 6 over RAID 5 is that with 5 disks it can theoretically cope with two disk failures. This gets round an increasingly common problem with large capacity RAID 5 arrays where if a second disk fails whilst rebuilding a failed disk, there should be enough parity information to continue the rebuild successfully.

It is important to remember that due to the complex nature of RAID arrays, it is crucial to make backups of the data to a different type of storage.

If you have a failed or broken LaCie 5Big then use the contact details on the right to contact us. Alternatively you can leave a comment here and we will get back to you.

Data Recovery In Hampshire

We are a specialist data recovery company in Hampshire recovering data from corrupt, defective and faulty hard disk drives. We are based in Copnor, Portsmouth and are an independent company, not part of a franchise. All of our work is carried out at our site, and not sent on to another company.

We offer data recovery on a national service. Some of the main areas we cover in Hampshire are Portsmouth, Southampton, Hayling Island, Isle of Wight, Gosport, Fareham, Basingstoke, Havant, Waterlooville, New Forest, Andover, Emsworth, Petersfield, Romsey, Winchester, Alton and Aldershot.

Our speciality is recovering data from hard disk drives, but we can also recover data from USB Pens, Camera flash cards and CDs, DVDs.

PC or Mac, we can recover either. Windows, Linux or Mac OS.

If you would like to use our data recovery service, please use the contact link near the top right of this page.

Our address is Dataquest International Ltd, 24 Domum Road, Copnor, Portsmouth, Hampshire, PO2  0QZ, United Kingdom.

LaCie Big Disk Recovery


LaCie Big Disk
LaCie Big Disk

Over the years we have seen stacks of LaCie Big Disks (and quite a few LaCie Bigger Disks too). With their designer looks and an abundance of different interfaces, it is no surprise that they are so popular. There is however one main reason that people send us their drives, and that is because they are not working.

Size Matters

Those of you familiar with hard drives will be aware that these LaCie drives are substantially larger in physical size and storage capacity when compared to a standalone hard disk drive. The reason being is that the LaCie Big Disk contains two hard disks (and the LaCie Bigger Disk contains four hard drives). Of course when you attach the drive to your computer you only see one volume. This is due to a RAID controller inside the LaCie drive which allows for multiple disks to appear as one large, usable disk. The main advantage to this setup is that read and write speeds can be very fast, as the reads and writes are spread over multiple disks. Another bonus is that the capacity of the volume is as large as the two drives. So two 500GB drives will give you a 1TB volume. There is however a massive downside to all of this clever RAID business which boils down to some simple mathematics.

Failures

The larger the number of hard disk drives used in this particular striped (RAID 0) setup, the more chance that one of them will fail, therefore a higher chance that you will lose all of the data stored on these drives. The way a RAID 0 stripe works is to distribute the data across the disks at block level. The amount of blocks used for each stripe is determined by the RAID controller and varies between different manufacturers. What this means, from a data recovery point of view is that in order to extract data from a LaCie Big Disk, you need to figure out the block size, and read the data from both drives in sequence, in order to extract usable data. This sounds a lot more complicated than it actually is and is often explained with the analogy of a filing cabinet.

Imagine the LaCie Big Disk is a filing cabinet. The cabinet has two drawers (disks) with an index in the first drawer. Now imagine that when you save a file into the cabinet, all of the odd numbered pages are put into the first drawer, and all of the even numbered pages are put into the second drawer. Once saved, the files location is stored in the index. In order to read back the saved file, it must first be collected from the relevant drawers, one page from each drawer at a time, and arranged into the correct order.

This is all great until a problem occurs. What happens when one of the drawers becomes damaged and can no longer be opened. Sure you can access all of the pages in the other drawer but having every other page is not much use to anybody! So until you can access both drawers, the documents are worthless.

Special Hard Drives?

The hard drives in a LaCie Big Disk are much the same as any other hard drive on the market. This means they are just as likely to have the same failures as a standalone drive. They suffer from electronic problems on the PCB, firmware corruption and also internal component failure and head crashes. These are problems which need to be overcome before any attempt at a recovery is even possible.

Aside from the usual hard drive problems, we have also seen other problems such as failed power supplies or damaged circuit boards within the LaCie Big Disk, which prevent access to the stored data.

This is why we have spent a lot of time researching the process of recovering data from RAID systems such as the LaCie Big Disk. We follow the same precautions with RAID as we do with single volume drives.

  • We make binary images of all of the individual hard drives on a read-only basis to protect against drive failure.
  • We don’t use the original hardware to read the RAID data, as this may be part of the problem.
  • We never write the recovered data back to the LaCie Big Disk, as this would prevent any further recovery process if it was required.

As with all data recovery, the most important thing to remember is that any attempts to access the data without following strict precautions could result in the data being either lost forever, or extremely expensive to get back.

The best advice is to keep these drives backed up as regularly as possible to avoid future headaches.

The Eight Commandments

1. Stop using the drive. Any mechanical faults can be worsened by using a failing hard disk drive.

2. Do not remove any covers or parts. Removing the top cover of a drive will introduce dust, particles, fingerprints and other contamination if not removed in a controlled clean environment. Some drives are also very difficult to realign once the cover has been removed.
3. DO NOT UNDER ANY CIRCUMSTANCES PUT YOUR DRIVE IN A FREEZER! This dangerous myth has been doing the rounds for so long that it is almost common knowledge but unfortunately only a small number of drives respond well to such treatment. The risk of allowing moisture by way of condensation into the drive far outweighs the likelihood of it actually allowing you to get your data back. We have a high success rate and have never had the need to put a drive in a freezer. Recovery from a water / condensation damaged HD is likely to cost you a lot more than a regular recovery.
4. If you are going down the DIY software route, keep a very close eye on the process. Make sure you recover the data to a second (external if possible) hard disk. If the process stops at any point, or if it incurs hundreds of errors then it is best to stop the recovery and get the data recovered professionally. Also if the software reports that it will take more than a few hours for a drive under 1TB then don’t let it continue. There is likely some damage on the drive which will only get worse if the drive keeps being used.
5. Never attempt to repair a failing hard disk drive. Any writing to an unstable drive will not only fail to fix the problem but it could make the eventual recovery extremely difficult or even impossible. If you cannot afford professional data recovery then we suggest trying to backup the data first and then attempt to fix the drive without any fear of losing the important data.
6. RAID ONLY: Do not attempt to rebuild or reinitialise a problematic RAID array without first backing up the data. If the data cannot  be accessed then a data recovery professional is far more likely to be able to get the data before a destructive rebuild process. It is also important to note the locations and IDs of all drives and label them accordingly if the entire server or RAID enclosure cannot be sent for recovery.
7. Don’t run Windows Check Disk without first backing up your data. If you see the blue message for the first time that says something like:
Checking file system on C:
The type of file system is NTFS
One of your disks needs to be checked for consistency. You may cancel the disk check, but it is strongly recommended that you continue.
To skip disk checking, press any key within  7  second(s).
 Press any key to cancel the scan, you should then backup your data as soon as possible onto another drive, USB pen, DVD, CD or even Floppy Disk. Then you can safely reboot and run the check. BEWARE: The drive can be warning you that it is on it’s last legs. It could be just a one-off problem or the drive could be destined for the dustbin (after a secure erase of course).
8. Be very wary of any potential data recovery company. You will be trusting them with your precious data after all. Ask lots of questions and get some quotes up front. You should expect to pay between £250 – £750 for a single hard drive data recovery. This depends on factors such as drive capacity, failure type and turnaround time.

The Worlds Worst Backup Solution; LaCie Big Disk Extreme+ 2TB

Anyone that has ever looked inside one of these “drives” will realise that they are only suitable for temporary storage capacity. There is nothing magical inside the enclosures, just a couple of standard hard drives and a small RAID 0 controller. What people (ie. general users) tend to do with a drive of this capacity is copy over all of the big data (pictures, movies and music) from their desktop or laptop computer and then delete it from the original location to save space. Not only is this not a backup but the chances of this drive failing are more than doubled due to the fact that the data is striped across two drives, either of which could fail at any time. In a RAID 0 only one drive needs to fail to take out all of the data.

One terabyte drive fails = 2TB of data gone!

Anyone thinking of using one of these should consider buying two and using software to mirror them. At least you would have some redundancy. There are of course much easier and not to mention cheaper ways to set up a redundant backup solution. We will post a more detailed guide of how to do this in the near future.