Re: SATA controllers and kernel port assignment in Linux

On Mon, 4 Dec 2006, John-Paul Stewart wrote:

darrins@xxxxxxxxx wrote:

Right now I have one drive on the motherboard (/dev/sda) and two drives
on the Card (/dev/sdb and /dev/sdc). The two drives on the card are
mirrored in a software raid-1 configuration. If in the future I add
another drive to the second port on the motherboard, it will be
assigned as /dev/sdb and then my raid drives will jump to /dev/sdc and
/dev/sdd. I can rebuild the raid at that point, but that always makes
me nervous

There shouldn't be any need to re-build the array. Assuming you're talking about a modern soft-raid with partition type 0xfd (RAID autodetect), the kernel doesn't care about the /dev/sd* names. What matters is the GUID that's written into the RAID superblocks of those devices. The kernel will create the RAID from the matching pair of GUIDs regardless of their /dev names.

Is there an easy, safe way to migrate from the old raidtools style RAID to the new auto-detect mdadm type arrays?

I suppose that I could manually fail one device in my old (RAID1) array and then define a partiton on this drive as a new mdadm-style array (with a missing drive), copy the data over, then re-partition and add the other drive and re-build, but is there an easier way?

Relevant Pages

  • Software RAID-1 with Mandrake9.0 problems - LONG
    ... I have configured RAID -1 ... md: md0: raid array is not clean -- starting background reconstruction ... ...trying to set up timer as Virtual Wire IRQ... ... host bus clock speed is 132.8612 MHz. ...
  • Re: Problems with software RAID on SATA
    ... Connected to this are two 320GB drives ... >>which I want to turn into a RAID1 array. ... >>I'm almost certain it's a problem with initting the RAID arrays at boot. ...
  • Re: RAID newbie...can I have several partitions on a RAID 1 array?
    ... You haven't expounded upon why you think you need raid. ... better backup device rather than buy 2 cheap RAID HBAs. ... RAID array then I would have to replace the mobo with the same one or at ... Lets say, for example, you buy 2 identical model drives, from ...
  • Re: Debian machine not booting
    ... Raid Level: raid1 ... Number Major Minor RaidDevice State ... Is /dev/md126 your preferred name for that array? ...
  • Re: [PATCH 000 of 5] md: Introduction
    ... "why linux raid isn't Raid really, why it can be worse than plain disk") ... After this, the array ... error is in the filesystem, due to the complex layout of raid5. ... hundreds or 1000s of drives, you've quite high probability that some of them will fail sometimes, or will develop a bad sector etc). ...