Re: Changing chunk size

[Bill Davidsen <davidsen@tmr.com>]

berk walker wrote:
>
>
> Bill Davidsen wrote:
>> Neil Brown wrote:
>>> On Thursday February 15, davidsen@tmr.com wrote:
>>>  
>>>> I have determined that a large array was created with an 
>>>> overly-large chunk size. Best way to resize?
>>>>     
>>>
>>> Dump and restore.
>>>
>>> in-place reshapes (such as raid5 + 1 disk => raid6 or
>>> change-chunk-size) are on my list of 'that might be interesting to
>>> implement', but there are plenty of more interesting things.  And it
>>> would be very slow.  It would need to copy some number of stripes to a
>>> backup somewhere, then copy them back in the new layout, so every
>>> block in the array would be written twice.
>> I'm sure "slow" is a relative term, compared to backing up TBs of 
>> data and trying to restore them. Not to mention the lack of 
>> inexpensive TB size backup media. That's totally unavailable at the 
>> moment, I'll live with what I have, thanks.
>
>
>> If you were to be a gambler, Bill - Get 2 disks big enough to store 
>> your data, create a RAID5 mising one, and copy over the data.  Re do 
>> the original array, and copy back.
> Yeah, $0.02 doesn't buy much anymore.  Besides, you'll be needing 
> bigger disks for the next machine you build,eh? 

Not unless the project leader say so. He can send me a note on a capital 
expenses approval form ;-)

-- 
bill davidsen <davidsen@tmr.com>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979