[CentOS] Order of sata/sas raid cards

Fri Aug 24 15:18:44 UTC 2012
Les Mikesell <lesmikesell at gmail.com>

On Fri, Aug 24, 2012 at 10:04 AM,  <m.roth at 5-cent.us> wrote:
>>> So, where's the big issue with std. labels?
>> You power down, add some disks that you want to re-use.  Maybe even
>> add a controller.  Just because a bay looks like you can hot-swap
>> doesn't mean it is a good idea if you don't have to.   You boot up.
> Okayyyy... We differ, here - I've come to adore hot-swap bays, and hate
> having to take a system apart to add another drive.

Same here, in terms of the actual swap.  But I'm old enough to
remember electronics that were sensitive to static, power
fluctuations, etc., so I generally power down while doing it.   And I
don't want to create a scenario where the machine might do something
unexpected if it did happen to reboot with the disks added.

> Reused disks - I reformat them, usually in a hot swap bay.

Same here, but I've had unwanted surprises from duplicate labels
before the format.  Hence the conclusion that duplicate labels are as
bad and idea as duplicate hostnames, IP addresses, or any other
identifier would be.

> Of course, I *do* have some additional concerns - I have to worry about
> PII and HIPAA data that may, *possibly*, be on the drives.

I normally don't have to worry about contents unless the disks leave the site.

>> When the label scheme was first rolled out, the machine wouldn't boot
>> if it found a duplicate.   Now it will pick one.  Possibly the wrong
>> one.  As you might when you do a rescue boot for the relabel since you
>> won't know which controller is detected first.
> But you can do a rescue, mount, and look at what's on what the controller
> found.

And they all look alike...

   Les Mikesell
     lesmikesell at gmail.com