Compaq Smart Array 3200 Controller as a SCSI Controller
cctalk at ibm51xx.net
Thu Jul 16 12:58:23 CDT 2020
> Are you sure that was RAID 0 (zero), /striping/? I've never heard of
> /software/ RAID 0 (striping) for the /boot/ drive in Windows. I would
> expect that to be RAID 1 or something other than the drive with
> NTLDR.EXE on it. I also suspect that the drive with %SystemRoot% on it
> would need to more conducive to loading driver and software RAID
> files very early in the boot process.
Absolutely correct. Proof reading good ;)! It was RAID 1.
> That's one of the reasons that ZFS supports three drives worth of
> redundancy in addition to the data space. RAID Z1 / Z2 / Z3.
Interesting. Is there an official RAID level for three drive parity? The Areca controllers do combined levels (e.g. 60 for two RAID 6 arrays stripped) but I don't think they do mirroring of parity RAID levels.
> I think that the CPU overhead / computation time is now largely
> insignificant. To me, one of the biggest issues is the simple massing
> amount of data that needs to be read from and written to multiple
> drives. At full interface speed, some drives can take a LONG time to
> transfer all the data. What's worse is the sustained I/O speed to
> platters of spinning rust being significantly slower than the interface
True. That is one of the points the article makes too. Basically, you can't get the data fast enough but that would be inherent in both SW and HW implementations. The only way to overcome that is to use SSDs I would think.
> Only have a few hundred GB on that multi TB RAID array
> consisteng of multipel 1 TB drives? Fine. Only need to check the few
> hundred GB. It's actually quite fast.
That is nice. I may have to look at it next time I do a RAID implementation.
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