Stripe and Mirror on the same two drives-Opinions Please?

[Trippp]

I am partioning two drives in my MacPro. The top partition is a striped raid with the OS and the bottom partition is a mirror raid with the majority of the data. This seems to work quite well, but I am interested in hearing if there is any pontetial difficulties or issues that I have not forseen. Perhaps maybe a conflict when there is data being moved on the stripe and the mirror at the same time? I want to set this up on my partners machine also and need to be sure that her business will survive my optimism.

We have plenty of redundant backup. My purpose here is to speed up the system but to have the data be immediately available for use with a external clone backup should one of the drives fail. Hence killing the Striped volume. Mostly I am not worried about data loss. My question revolves around whether there might be data corruption or premature wear on the HDD's or whether the mirror might degrade the performance of the stripe as to make it unattractive.

We do do not have room for more internal drives at this point do to an internal backup/mirror. We at this point have redundant backup systems. I am familiar with the fact that mirrors do not make a backup. But they sure do make an instant recall easy from a single drive failure.

Thanks

 

[nanofrog]

I am partitioning two drives in my MacPro. The top partition is a striped raid with the OS and the bottom partition is a mirror raid with the majority of the data. This seems to work quite well, but I am interested in hearing if there is any potential difficulties or issues that I have not foreseen. Perhaps maybe a conflict when there is data being moved on the stripe and the mirror at the same time? I want to set this up on my partners machine also and need to be sure that her business will survive my optimism.

We have plenty of redundant backup. My purpose here is to speed up the system but to have the data be immediately available for use with a external clone backup should one of the drives fail. Hence killing the Striped volume. Mostly I am not worried about data loss. My question revolves around whether there might be data corruption or premature wear on the HDD's or whether the mirror might degrade the performance of the stripe as to make it unattractive.

We do do not have room for more internal drives at this point do to an internal backup/mirror. We at this point have redundant backup systems. I am familiar with the fact that mirrors do not make a backup. But they sure do make an instant recall easy from a single drive failure.

Thanks

Sharing multiple RAID configurations on the same members has the following compromises associated with it:

1. Performance degradation when used simultaneously (one servo that moves the heads, so they go like mad moving about to access the next data request/write in the queue).
2. Additional wear = reduced lifespan of the disks (you'll see failures more frequently, particularly on consumer grade disks).
3. Failure of any array affects all of them (in your case, the data on the stripe set would be gone, and the mirror degraded by the loss of a single member).

As to what would be a better solution for the specific needs, more information would be needed (i.e performance, capacity, capacity growth rate, and redundancy requirements).

The resulting solutions could be between a simple eSATA based solution, up to a proper hardware RAID system.