Large number of IOPS on ASM subsystem. Is it logical

I have an IBM 520Q system with Oracle 10.2.0.3 Standard Edition, and RedhatLinux 4 AS. The oracle data files are on ASM, which is 4 UltraSCSI disks on soft raid 10 by ASM. The problem: I haven't noticed it before, but by logging via the enterprise manager on the ASM instance, at the performance tab I saw a graph of the IO operations per second, and that was extremely large. I had values of 100000 to 300000 io op/s. As I have red in various sites, these values can't be true, because hard disks cannot give such big values, even specially made equipment with flash memory give 200000 as a peak.
I searched the Internet but haven't found something to clarify this. The only conclusions I come are that a) although it writes I/O Operations it doesn't show this exactly b) although the label on the graph shows thousands, it is not c) the ASM instance does a lot of self caching or something like that, showing increased performance, and the numbers are not the actual of the disks used.
Another strange aspect of this behavior is that the number of IO operations/second increases steadily for a timeframe of 15minutes to a peak (which may be as large as 100K, 200K sometimes 300K I/O operations per second according to load), then at the 15 minutes suddenly drops to zero, and starts again.
I would like any help to clarify this situtation.

I have asked the author of the doc in question to respond here in the forum to this thread.

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How to design Storage Spaces with a large number of drives

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In the hardware raid world, i would divide these 45 x 4TB drives into three separate 15 disk Raid 6's. (Thus losing 6 drives to parity) Each raid 6 would show up as a separate volume/drive to the parent
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Here is my best guess for storage spaces. I would create 3 separate storage pools each containing 15 disks. I would then create a separate
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to the parent OS. Did i miss anything?
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I am wondering how one might go about designing a storage space for a large number of drives. Specifically I've got 45 x 4TB drives. As i am not extremely familiar with storage spaces, i'm a bit confused as to how I should go about designing this. Here is
how i would do it in hardware raid and i'd like to know how to best match this setup in Storage Spaces. I've been burned twice now by poorly designed storage spaces and i don't want to get burned again. I want to make sure if a drive fails, i'm able to properly
replace it without SS tossing it's cookies.
In the hardware raid world, i would divide these 45 x 4TB drives into three separate 15 disk Raid 6's. (Thus losing 6 drives to parity) Each raid 6 would show up as a separate volume/drive to the parent
OS. If any disk failed in any of the three raids, i would simply pull it out and put a new disk back in and the raid would rebuild itself.
Here is my best guess for storage spaces. I would create 3 separate storage pools each containing 15 disks. I would then create a separate
Dual Parity Virtual Disk for each pool. (Also losing 6 drives to parity) Each virtual disk would appear as a separate volume/disk
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Additionally, is there any benefit to breaking up my 45 disks into 3 separate pools? Would it be better to create one giant pool with all 45 disks and then create 3 (or however many) virtual disks on top of that one pool?
1) Try to avoid parity and esp. double parity RAIDs with a typical VM workload. It's dominated by small reads (OK) and small writes (not OK as whole parity stripe gets updated with any "ready-modify-write" sequence). As a result writes would be DOG slow.
Another nasty parity RAID characteristic is very long rebuild times... It's pretty easy to get second (third with double parity) drive failure during re-build process and that would render the whole RAID set useless. Solution would be to use RAID10. Much safer,
faster to work and rebuild compared to RAID5/6 but wastes half of raw capacity...
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CCTV storage you'll absolutely need all IOPS from all spindles @ the same time. This again means One Big RAID10, OBR10.
Hope this helped a bit :) Good luck!
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Ah, I see,
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greetings Marsian

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Large number of IOPS on ASM subsystem. Is it logical

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