ddrueding said:
...I really need Areca's 20-port PCI-E RAID adapter for a 6TB+ iSCSI NAS I'm quoting...
It isn't mentioned very often, but be aware of the 2 TB SCSI limitation. This applies even if you are using SATA or PATA drives because RAID host bus adapters and their drivers commonly emulate SCSI host bus adapters.
The 2 TB limitation also means that the total number of partitions on a physical array can't add up to be larger than 2 TB. Even though modern file systems can handle multiple PetaBytes or ExaBytes, the SCSI command set is deficient.
To tackle this deficiency, a new 16-byte SCSI command set has begun being implemented. LSI Logic recently released new SCSI and FibreChannel silicon (and drivers) for host bus adapters that support the 16-bit SCSI read / write / seek commands.
There should now be a new round of PCI-X and PCI Express RAID host bus adapters with 16-bit SCSI command support -- especially for hosting large numbers of 300 GB SAS hard drives as one array. SCSI (and F-C) hard drives likely won't have native 16-bit command support for a quite a while, since SCSI hard drives would need to have a storage capacity of 2 TB or larger to require such.