Help, my disk array has one dead member

[Kevin O'Gorman]

Well, okay, this should be my "real" last word.

I had no idea what to expect.  But I put my 3 drives into USB3 drive docks
(my 3rd one arrived today).  mdadm is now projecting RAID5 will be finished
in 4.6 days.  Egad!
I guess it makes sense.  7.4 Tib to read, 3.7Tib of parity to write.

I think it made 512-byte blocks.  Would anything go faster if I changed
that or any of the other defaults?


On Thu, Mar 23, 2017 at 6:34 PM, Kevin O'Gorman <kogorman at gmail.com> wrote:

> OP with his last word.
>
> Thanks for all the ideas.  Some I didn't know about.  Some I did but you
> connected dots for me that I hadn't put together.
>
> Special thanks to Karl for the link to RAID tutorial.  I didn't know that
> 3 drives is enough for redundancy;  I thought it was 4.  I may switch to
> RAID-5 as it is starting to look like I don't need 11 TiB, but that 7 would
> do nicely.
>
> I've recovered the main database to where it was when raid failed.   The
> rest of the files are either scripts or mostly of historical significance
> (actually, they are just symptoms that show I'm a data packrat).  And I
> seem to have (or have recovered) all of the scripts I use very much.  So
> that machine is back to running (in a very restricted partition for now).
> The other machine will be building a new RAID array and doing a few tests
> on the drives from the old RAID.  By next week, I'll be re-ordering drives
> for my second (or is it third?) RAID array.
>
>
> On Thu, Mar 23, 2017 at 5:49 AM, Bruce Ferrell <bferrell at baywinds.org>
> wrote:
>
>> On 03/23/2017 02:11 AM, Liam Proven wrote:
>>
>>> On 22 March 2017 at 22:36, Bruce Ferrell <bferrell at baywinds.org> wrote:
>>>
>>>> it's either needless (this is why we use a RAID)
>>>>
>>>
>>> WHAT?!
>>>
>>> The #1 thing that any competent storage admin will tell you, or any
>>> guide book, is this:
>>>
>>> *RAID is not a replacement for backups.*
>>>
>>> Yes you still need to copy the stuff off it. If the user has never
>>> done a disk swap before and switches the wrong disk or something, all
>>> data will be lost. If the problem is not just a failing disk, all data
>>> will be lost. If there are issues with controller, cabling, filesystem
>>> corruption, anything except a failed disk, data will be lost.
>>>
>>> This is terrible, awful advice.
>>>
>>>
>>>
>>> RADI is not
>>>
>> I was talking about in the context of disaster recovery.
>> Not overall storage management.
>> When I'me cleaning up from a failed disk, one must perform triage.
>>
>> 1.) priority is recover the operation.
>> 2.) is everything else
>>
>> if you try to do everything all at once, y'all got a good change of
>> losing everything
>>
>> Of course purists everywhere will armchair quarterback anyway
>>
>>
>> --
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>
>
>
> --
> Kevin O'Gorman
> #define QUESTION ((bb) || (!bb))   /* Shakespeare */
>
> Please consider the environment before printing this email.
>



-- 
Kevin O'Gorman
#define QUESTION ((bb) || (!bb))   /* Shakespeare */

Please consider the environment before printing this email.
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