[mythtv-users] Question re: available SATA ports and linux software RAID

[Mark Lord]

On 11-04-07 01:06 AM, Bobby Gill wrote:
..
> (I was considering the HighPoint 2300 PCIe controller card but after
> communicating with their web support, they confirmed to me that multiple
> controller cards of theirs (any?) cannot be used in conjunction to form an array
> (one card = 4 slots so I couldn't buy 2 cards and build an 8 drive array on the
> same mobo).)


Their telephone support folks are mostly unaware of "software RAID",
they they were really thinking "Highpoint hardware-assisted RAID" there.

However, I would not get a "RAID" card, and especially not a "HighPoint" RAID.

The problem with HighPoint in particular, is that their BIOSs have a nasty habit
of corrupting data on "JBOD" ("non RAID") drives.  The BIOS writes a "metadata"
block to any drive it detects at boot time, without regard to whatever data
or filesystem might already be on the sectors it overwrites.  Duh..

If you have the slots, then get a few 4-port SiliconImage cards from DealExtreme.
Otherwise tread very carefully with the HighPoint cards, and heed the metadata
warnings.  Here is the text I put into my sata_mv kernel driver as a reminder:

/*
 * Highpoint RocketRAID PCIe 23xx series cards:
 *
 * Unconfigured drives are treated as "Legacy"
 * by the BIOS, and it overwrites sector 8 with
 * a "Lgcy" metadata block prior to Linux boot.
 *
 * Configured drives (RAID or JBOD) leave sector 8
 * alone, but instead overwrite a high numbered
 * sector for the RAID metadata.  This sector can
 * be determined exactly, by truncating the physical
 * drive capacity to a nice even GB value.
 *
 * RAID metadata is at: (dev->n_sectors & ~0xfffff)
 *
 * Warn the user, lest they think we're just buggy.
 */

I suspect that all of the "HighPoint" brand cards do something similar.

Cheers