Re: [tlug] White Box: Some Assembly Required ...

[CL <az.4tlug@example.com>]

On 06/25/2018 09:49 PM, Jens John wrote:
> >From the looks of it, I suspect that AMDSB950 has a "fake-RAID" chip which cannot do RAID on its own but needs additional operating system support (see e.g. [1]). The driver situation on Linux seems unclear. So I suggest that if you want some kind of stable RAID configuration, you drop the board's RAID functionality and focus on a software RAID setup in Linux (possibly with LVM, your choice, though IMO LVM is always a usability improvement) or purchase a real RAID controller card, if possible from a widely-used vendor like LSI (which has in-tree drivers) to bypass issues with crappy hardware and firmware.

The SB950 was standard equipment on all ASUS boards for about four 
years, so I tend to discount descriptions of that as "crappy" hardware.  
I don't find any references to "fake-RAID" in the documentation of the chip.

I have set up and am testing a six-disk RAID5 which uses the disks 
connected to the add-in board and two motherboard connected HDDS plus 
the startup array of the SSD and CD/DVD.

I reinstalled Lubuntu with an LVM and used mdadm to create the software 
RAID.  One point to mention in all this is that grub refused to install 
when I installed directly from a Lubuntu 18.04 .iso.  I had to begin 
with 16.04 and progressively upgrade to get back to 18.04 with LVM and 
proper grub setup.  I'm going to do some test copy-overs from the pile 
of internal storage disks I've been saving to check on the solidity of 
the arrangements.

> Note that should you choose to use the SATA port multiplier at all, SMART command passthrough may be an issue, making the monitoring of the drives' health difficult or impossible (typically, you'd use the smartmontools for this, but some hardware like port multipliers requires custom SATA commands to be able to address specific drives behind a port multiplier). I suggest you crosscheck with the smartmontools mailing lists to see if there are issues with the hardware you're looking to use.
>
> [1] https://forums.linuxmint.com/viewtopic.php?t=225489
From what I have been able to glean from multiple sources, a lack of 
SMART command pass through does not appear to be an issue with the 
Asmedia 106 series.  There is a huge amount of commentary on this 
particular chip, which appears to be installed everywhere.

CL