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26

Drive manufacturers specify the reliability of their products in terms of two related metrics: the annualized failure rate (AFR), which is the percentage of disk drives in a population that fail in a test scaled to a per year estimation; and the mean time to failure (MTTF). The AFR of a new product is typically estimated based on accelerated life and stress ...


17

Unfortunately the MTBF isn't what most people think... It is not how long a an individual drive will last. Manufacturers expect their drives to last as long as the warranty, after that it really isn't their problem. Older electromagnetic platter hard drives will seize up after 10 or so years. Integrated circuits last an extremely long time, but other ...


16

It's a waste of time. You won't be able to induce failure or stress the drives in a meaningful manner. You have RAID, and that's a good start. Just make sure you have monitoring in place to actually detect failures as they occur and backups to protect against disaster.


5

It may be better to use different brands or series of disk together if you're worried about this. I have seen disks of similar type and age fail in clusters, so IMHO it's not an urban leend.


2

Great Question - However, unlike automobile headlights, this is a waste of time. The MTBF [mean time between failures] rating for 4 GB drives [WD Red in this example] is 1,000,000 hours. The odds of two drives going bad in a mirror at the same time is extremely rare. When I have seen this happen, it is has been because the first drive failed without ...


2

They come from a statistical evaluation based on a small sample size and a short amount of time. There's really no universally agreed upon method or process so it's really just silly 'marketing'. This article may explain it a bit more. And Wikipedia has some formulas which might be what you're looking for? Essentially, for nearly everything (including ...


2

You should take images of all the RAID member drives with a tool like dd_rescue, and then assemble a RAID volume with these images. This way you don't put any extra stress to the failed hard disks, and you have the best chance to recover data.


2

Here's a list of things to check. Are these HP disks? Are they generic disks installed in HP drive carriers? For the 500GB drive that appears to be 1TB, if it's HP-branded, HP replace older smaller capacities with larger disks, depending on product availability. 500GB SATA disks aren't made anymore, so that could be a reason. It is unlikely that your ...


2

Are you sure that's the required solution for you? You are basically asking for a clustered solution for web hosting. Generally IIS is best left out of clustering and should utilise Network Load Balancing (NLB) instead. With NLB you will have both servers up simultaneously and split the load between them. If one of them goes down the second will handle all ...


2

You can do this by Microsoft NLB, or IIS shared configuration as Lior mentioned. You can also use the "Application Request Routing" or a hardware load balancer but all depends on the environment, resources and your requirements. Here are some resources: https://technet.microsoft.com/en-us/library/jj129384.aspx ...


2

Call your IBM reseller. They can get it. (as Newegg/amazon still have it in stock) A tip for IBM, HMM. Google 7945 HMM, and open first link. http://publib.boulder.ibm.com/infocenter/systemx/documentation/topic/com.ibm.sysx.7945.doc/PDF_4255_7945_7949_PDSG.pdf Page 387, send that to the reseller


1

Bad news about MTBF is that common evaluation metodics suppose evenly distributed write load among all NAND cells. But cells are grouped into the clusters and when one single cell fails - whole cluster is marked as dead and is replaced with new one from the reserve. Usually reserve is about 20% of the SSD volume. When reserve is exhausted whole SSD will be ...


1

If I understand things right your /dev/md3 is raid5 and should consist of /dev/sda3, /dev/sdb3, /dev/sdc3 (which no longer exist) and /dev/sdd3. So what do you get from mdadm --detail /dev/md3? Why does /dev/sdc still seem to have a broken partition table? Maybe it would be possible to restore your data even though the partitions from /dev/sdc are still ...


1

Look at the lights on the drive... Are they amber? Why do you think the drive failed? If the drive failed, why is the server off (or why was it powered off)? I'm sorry the drive is not in a RAID, but seeing that also indicates that your server/RAID controller firmware and ESXi installation are likely outdated. There are older Smart Array firmware ...


1

While it makes sense in theory, the data doesn't support the need to work in your drive. Not only will a few weeks not really make an impact, the failure percentages don't really work when looking at only two drives. While there has been some indication of more normalized failure rates when it comes to drives of the same model. Most age-related results ...


1

I can really only see a couple of options here. They both assume that the only thing on this datastore is the VMDK that's housing the SQL Server's MDFs. No VMX files, no log files, no datastore heartbeating. The first would be to unmount the volume on the host in question. You can do it via the vSphere clients, esxcli or it's PowerCLI equivalent. I don't ...



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