Posts Tagged ‘computer services’

Recovering Data From A Failed Council SAN Server

Monday, January 27th, 2014

As a contractor in the computer support industry I come into a lot of contact with servers and RAID arrays. In fact, my main job is looking after the data held on SAN servers and other form of Network Attached Storage. I work for companies and government institutions as a sort of freelance computer troubleshooter and mostly use IBM, Dell and HP server equipment. The Dell servers are typically Dell Poweredge series and the HP kit is mainly Proliant. Again the equipment is hooked up to a SAN data network.

Data redundancy is a big problem of mine, it’s what happens when I inherit old legacy systems that really should have been decommissioned years ago but because of budgetary constraints have continued to be used. I work on several HP Proliant and Dell SAN servers that I’d love to switch off and migrate the data onto something far more up to date like a Dell Blade or IBM X Server system. Unfortunately, I don’t really have any say in buying new equipment.

Older servers and computer equipment fails more regularly, it just does. It wears out, hard drive fail, memory goes bad and UPS’s fail. What greeted me when I came into work last Monday was a failed SAN server array – 12 disks running in a RAID 5 configuration with a hot spare. Analysis of the server logs showed that one of the hard drives had dropped out of the array on Saturday causing the hot spare to click in. This had seemingly worked fine – the hot spare should simply be ‘rebuilt’ back into the array, but instead the whole array had fallen over.

SAN data recoveryIn the server room the SAN’s RAID BIOS reported that three of the hard drives had now dropped out from the array. Well, that would explain why the SAN server was no longer booting the array. What had caused the three drives to fail was at this point a mystery. The server in question was one that ran part of the council payroll so it was obviously important to get the SAN back up and running as soon as possible, but obviously this had to be done in a method that followed best practice. It became my task and no data could be lost in recovering the SAN either.

Now I’m good a IT and SAN server support I’ll admit but when I discover 2 of the 3 drives that had dropped from the array had mechanical faults, the problem was beyond my abilities. I used a data recovery company a few years back but they were no more. Searching online pointed me to a specialist SAN recovery company called RAID and Server Data Recovery, an online review or two told me they could be trusted and that they were recommended, so I called them.

I spoke to RAID and Server Data Recovery’s specialist SAN recovery team who confirmed what I thought already. Some of the drives had mechanical damage and would need clean room attention in order to progress the data recovery attempt. I got clearance for the costs from finance and loaded the SAN server into the car and drove it down to the recovery company.

Analysis showed 1 drive had a head crash while the other two had firmware issues. Firmware is code that runs the hard drive’s operating system. It can corrupt and when it does the hard drive fails. It seemed that this firmware problem was the cause of the SAN crashing and all that needed fixing was the firmware on the two failed drives. This was indeed the case and after the repairs to the hard disks were completed and the drives re-integrated back into the SAN RAID BIOS, the SAN came back online and the data was accessible again. Panic over. The data was fully restored which was the outcome everyone had wanted.

Data Outage Hits Dropbox Users

Tuesday, January 14th, 2014

Dropbox logoOn the evening of Friday 10th January 2014, Dropbox engineers accidentally deployed a software upgrade to their active data servers, bringing down Dropbox completely. While the service was partially restored within three hours, some users were still experiencing issues more than 24 hours after the initial outage. Dropbox has issued an apology and reassured users that their data is safe following the significant service outage over the weekend.

Following a high profile password hijacking incident in 2012, Dropbox was swift to try and quell anxieties that Friday’s outage had been from a data violation or distributed denial of service (DDoS) attack. Instead a software bug was to blame and a Dropbox spokesman explained that despite running two copy “slave” machines, the bug resulted in many master machines as well as their slaves going down concurrently, producing a loss of service.

In addition, the company has developed applications to speed up the recovery of substantial MySQL copies, a tool Dropbox said would be published into the open source community so others could profit.

Dropbox had learned from this weekend’s troubles and had taken steps to ensure the bug wouldn’t be replicated. These measures contain an added level of tests that require machines to locally check their state before running incoming commands, which gives machines the right to reject orders when they would create a “harmful” consequence.

As the marketplace for affordable cloud storage grows, the outage once again emphasised the value for cloud storage companies to keep data reachable constantly so that customer belief can be preserved. The outage also demonstrated the brittle nature of cloud storage.

Data Clinic Help Businesses Recover From Weather Damage

Tuesday, December 10th, 2013

dataclinic ltd logoHigh tides and strong winds combined to defeat flood defences and damage many shops and businesses in Hull this week. Companies, shops and houses were evacuated as flood water disrupted computer systems causing them to crash and their data to be lost. Subsequently IT support companies have been called into many businesses to restore failed computer systems such as RAID servers, stand alone PC and Mac computers. Recovery work is also underway across the region as companies try to restore their computer data and get their businesses back up and running again.

Flooding causes widespread disruption to computer systems and large scale data loss. Hard drives that have been involved in floods are often water damaged and have to be cleaned and carefully dried before attempts to access the data on them can be made. The drying process has to be very carefully managed as once a hard drive begins to dry out its components begin to oxidise. Oxidation of the hard drive must be prevented as it will prevent any type of successful data recovery result. One of the worst things that can be done is for a water damaged and oxidised hard drive to be powered up. Doing so will damage the platters of the drive and destroy the data.

Water damage will frequently break the hard drive controller board by causing a short circuit. Swapping the controller board will no work because controller boards are now unique to the hard drives they are shipped with and contain data unique to that hard drive.

A recommended data recovery company like Data Clinic are specialists in recovering the data from flood and water damaged hard drives. With many years experience in hard drive faults and data recovery they are often the company of choice for many UK businesses and individuals. With regional offices throughout the UK, customers can call in and have their hard disk assessed or take advantage of a countrywide free collection service. Drive faults and damage is assessed and then a price given for the recovery of the data. It’s then the customer’s choice whether they wish to proceed with the recovery or not.

With all the bad weather around the UK at the moment it’s not only Hull that is suffering, many businesses on the East coast of England are also taking the brunt of the poor conditions with shops staying shut and business data going offline. Computers and hard drives are resilient to many things but bad weather is not one of them, and those businesses without data backups are in for an agonising wait while the data recovery firms work at repairing their hard drives and recovering their data.

Whether it’s for your business or personal use, you can’t go wrong backing up your data.  You should always create a backup of your data at least once a month, even more than that if you have a lot of important information that you add to your laptop on a frequent basis. To put it in simple terms, nothing in the computer industry is fool proof.  Hard drives can crash, computer hard disks can get stolen, or be dropped and rendered useless. To ensure that we are never left without our valuable data, we should always create a backup of our information. There are several methods available that ensure data is backed up. Online services that back up data remotely can be used, alternatively so can external hard drives. Another cheap way to back up data and files is to burn them to a data CD or DVD. If you don’t have that much data to back up you could also use a USB memory stick. Preserving data is something you should really look into, especially if you have business material on your hard drive.

As mentioned above, the easiest and quickest way to backup important data is to use an online backup service.  Depending on your internet connection this can take from several minutes to several hours. It is time well spent though because at least you’ll know your data is safely stored to somewhere other than your hard disk should the drive crash. It would be an interesting study to discover how many businesses and households have lost data because of the recent flooding, what percentage of them had made backups and what percentage had to use data recovery services to rescue their data from their flooded hard disk drives.