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I need to install a pair of 1Tb disks into a server that has a hardware RAID card.

How long is it likely to take to configure the RAID controller - sticking the disks in is only a 5 minute job, but is there likely to be significant downtime while both disks mirror (even though they are both blank)? Am I looking at 10 minutes over all, or more like 2 hours for this to happen?


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up vote 3 down vote accepted

Obviously you don't let us know what controller it is but usually it's just a case of inserting the disks then creating the mirrored array either via a BIOS extension menu or via an application inside your OS - this usually takes seconds as there's nothing to mirror bar the basic FS data. You can then either load you OS and it'll be seen as a single disk or you might have to rescan for disks if you did it online. Once the OS knows of it you just partition an format, job done.

Basically you're looking at 10 minutes or so.

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ok great. thanks. – Roger H Jun 17 '10 at 9:35

In most cases, you can initialize the raid online, but this means a (sometimes heavy) performance degradation while the system is working. I am not sure how heavy this is with raid1.

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Some of the RAID controllers I've used take several hours to sync RAID 1 disks, even empty disks. However, you should still be able to use the drives while it's syncing. While they are syncing, there may be some performance degradation, and obviously you won't have a usable mirror until the syncing is complete.

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