From: John Robinson <john.robinson@anonymous.org.uk>
To: Bill Davidsen <davidsen@tmr.com>
Cc: Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: Removing a failing drive from multiple arrays
Date: Thu, 26 Apr 2012 07:19:14 +0100 [thread overview]
Message-ID: <4F98E8E2.6070503@anonymous.org.uk> (raw)
In-Reply-To: <4F98B4FE.5010101@tmr.com>
On 26/04/2012 03:37, Bill Davidsen wrote:
> John Robinson wrote:
[...]
>> Without either hardware or BIOS RAID, you can still end up being
>> unable to boot,
>> e.g. the BIOS will try to boot from the first hard drive present, but
>> if it has
>> bad sectors in the MBR or /boot partition, booting may fail even
>> though there's
>> a perfectly good mirror on the second drive, because the BIOS doesn't
>> understand
>> RAID. This has happened to me :-(
>>
> Doesn't need to understand RAID, just be willing to try the next item in
> the boot list on failure. My experience has been that almost every BIOS
> will try the 2nd item if the 1st fails totally (ie. drive isn't there).
> A _good_ BIOS will try the next item on sector error in the MBR.
Absolutely - but in the case I had, grub couldn't load its next stage
because of a sector error.
It probably didn't help that the weekly array scrubs don't touch the
space between the MBR and the first partition, where that code lives.
> After that the BIOS needs to understand a lot more to do anything
> smart after the MBR runs.
Agreed; only a RAID BIOS (software e.g. IMSM or hardware RAID card)
could have saved me from the above failure.
Cheers,
John.
next prev parent reply other threads:[~2012-04-26 6:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-19 18:54 Removing a failing drive from multiple arrays Bill Davidsen
2012-04-19 21:52 ` NeilBrown
2012-04-20 14:30 ` Bill Davidsen
2012-04-22 22:33 ` Bill Davidsen
2012-04-22 22:55 ` NeilBrown
2012-04-25 0:07 ` Bill Davidsen
2012-04-20 14:35 ` John Stoffel
2012-04-20 16:31 ` John Robinson
[not found] ` <CAK2H+efwgznsS4==Rrtm6UE=uOb25-Q0Qm84i8yAJEJJ2JLdgg@mail.gmail.com>
2012-04-22 18:41 ` John Robinson
2012-04-26 2:37 ` Bill Davidsen
2012-04-26 6:19 ` John Robinson [this message]
2012-04-26 7:36 ` Brian Candler
2012-04-26 12:59 ` Bill Davidsen
2012-04-26 13:23 ` Brian Candler
2012-04-26 21:17 ` Bill Davidsen
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