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What are the RAID levels in SQL Server?
The act of fine tuning these functions requires configuring what’s know as the “RAID Level”. RAID Levels are a set of industry known configurations for RAID Arrays. The most common RAID Levels are RAID 0, RAID 1, RAID 5, RAID 1+0 and RAID 0+1. Depending on the RAID Level you choose, you pay what is known as a RAID Penalty.
Can you write a log file on RAID 1?
IMHO keeping Log file on RAID 1 would make writing slow as compared to RAID 10. Data needs to be mirrored and would not be much good in terms of capacity as its half due to mirroring. Still I would say RAID 10 even RAID 5 has been seen to have slower writing speed for log files.
What is the performance penalty for RAID 1?
RAID 1 writes each piece of data to 2 seperate disks. That way if any individual disk fails, its clone will take over processing, and the user never knows a failure occured. RAID 1 does have a performance penalty for writes. Each write IOP has to be performed twice (you have to write every piece of data to two disks).
How does RAID 0 affect data throughput and performance?
Although RAID 0 does dramatically improve IO performance and throughput, it does not provide any degree of fault tolerance. That is, if any single disk in the array fails, the entire array is shot and all the data on it is lost.
What happens if a disk fails in RAID 5?
RAID 5 can tolerate only 1 disk failure, RAID 10 can potentially lose up to 1/2 the disks and still work. Even worse, is how the array performs when a disk fails. Although you won’t lose data, a RAID 5 with a failed disk must perform a XOR operation on every sector read to recover the data.
What’s the difference between RAID 0 and RAID 10?
Here’s one way we can put it: 1 RAID 0 and RAID 10 have effectively no latency or impact. 2 RAID 5 has some latency and impact 3 RAID 6 has roughly twice as much computational latency and impact as RAID 5 4 RAID 7 has roughly triple the computational latency and impact as RAID 5