Re: Changing chunk size

[berk walker <berk@panix.com>]

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?

b-