I will help start this and leave some room for others to add input.

### Disks
If I plan an DSS7 Active/Passive iSCSI cluster with 8TB or 16TB diskspace, how many disks and what HW-Raid level do you suggest?
8TB: 3 Disks? 4 Disks? RAID5?
16TB: 5 Disks? 6 Disks? ...
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Min. of 8 disks as this is best for best IOPS.
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### Disk Technology
Is there a big (real world) performance difference between SAS and SATA disk?
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Yes there is especially with 10K and 15K SAS drives.
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### Controller
In the past I used mostly LSI Controllers. Any suggestion here?
Write Cache with BBU yes/no?
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Yes unless you have a really good UPS.
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### Network
I use MPIO for iSCSI with 2-4 1GBit Ethernet. The next storage I plan to setup with 2x 10Gbit MPIO with an Intel NIC. Ok?
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All good, bonds are for NAS and MPIO for SANs.
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### CPU
Single CPU with 2-4 Cores? How much does Open-E benefit from multicore?
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Quad core or more is good.
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### Memory
If I check the memory usage, Open-E does not use a lot... 8GB memory still enough or better 16 or even more?
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8GB is enough for 16TB
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