https://bugzilla.novell.com/show_bug.cgi?id=350573
User teheo@novell.com added comment
https://bugzilla.novell.com/show_bug.cgi?id=350573#c8
--- Comment #8 from Tejun Heo 2008-01-07 19:04:18 MST ---
There are actually three types of RAIDs.
1. h/w RAID - as Dejan described.
2. s/w RAID - mdX, as Dejan described.
3. fake (BIOS) RAID - 99% of [SP]ATA controllers which advertise that they
support RAID actually don't have any hardware to support RAID. They are all
plain ATA controller which can speak to attached devices as directed by the
operating system. The only difference from pure software RAID is that the code
stored in the flash chip (BIOS) knows the used RAID format and can boot from
RAID.
In that sense, BIOS RAID is purely software too where the BIOS and the
operating system use the same software RAID format. Before the OS boots, BIOS
runs the RAID code. After the OS boots OS code runs its RAID code - which is
dm in Linux.
Fake RAID is usually worse than software RAID. There are several on-disk
formats out there, so when you change system configuration you might need to
rebuild the array and not all BIOS RAID implementations are of good quality.
Unless there's specific reason to use fake RAID (ie. some other OS requires it
or whatever), it's always better to use md && grub can boot from md RAID1.
That said, the reported problem doesn't look like a libata or dm problem. I
agree with Dejan that most likely cause is misconfigured initrd.
--
Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.