How do I monitor RAID status when using an external eSATA RAID5 SATA port multiplier?

Solution 1:

You may be one of the only people who have run into this issue :)

Well, possibly... The use of SATA multipliers is a no-no in server-class systems. Heck, using SATA is a bit risky these days, with ever-increasing drive capacities.

It's not surprising that you've had a difficult time finding information about the SATA port multiplier and monitoring under Linux. Using a SAS expander is the preferred and more supportable approach. Expanders are the norm for server backplanes and external storage JBOD enclosures. As a result, port multipliers are somewhat rare and don't have much mindshare. Adding a layer of abstraction through eSATA almost eliminates any chance of your drives being exposed to the OS, unless the card you're using in the host has OS-lever driver support.

What type of eSATA host card are you using?

At this point, I would rely on the enclosure and visual LED status checks to determine array health. Provide more information about the device, and there's a slim chance status can be communicated to the host (if using the right card), but I wouldn't expect it otherwise.

Edit:

The enclosure being used here does not have LED indicators for drive health. You won't have any way of visually determining drive array status or doing this via your host.

Edit

I reached out to the manufacturer for support:

The OP post a wrong part that is why no one can help :-) See: https://serverfault.com/a/644247/13325

Solution 2:

This is DATOptic-Support Team, the manufacture of the 1U stand-alone Hardware RAID.

The control uses in this 1U rack is NOT SiI-3726.

It is JM393: http://www.datoptic.com/ec/5x-drive-hardware-raid-controller.html There is some GUI in Linux but not all flavor - go the page and click support TAB There is some CLI and OpenSuSE RAID GUI...