Re: LINEAR RAID, little help

[Rich <rich@pcfusion.co.uk>]

I forgot to ask something, sorry. With RAID0 and all the odd size drives 
I have I'd get a lot of left over unused space. Is there anyway to make 
use of this slack?

Thanks,

Rich

Rich wrote:
> Neil Brown wrote:
>> (This is maybe sort of off topic since this list about raid and not
>> filesystems and virtual such either.)
>>
>> Maybe you just want the appearance of things being as one volume? I
>> might recommend you looking into unionfs:
>>
>> http://www.filesystems.org/project-unionfs.html
>>
>> It's actually quite useful. You might have some logical division of the
>> data. Put TV stuff on one disk, Movies on another. The unionfs overlay
>> maps everything together into a virtual bigdisk. It's also very simple
>> and no superblocks or headers needed either.
> Thanks I shall take a look into it :)
>>
>> Linux raid0 works with varying sized drives without problem.   
> Ah, kewl.. I might do, depends how much drive space I loose. Speed 
> wise I don't find linear to bad I can read and write over gigabit 
> network at around 30mb/sec.
>>
>> If you lose one drive, you should consider that you have lost the
>> whole array.  You might be able to recover some data, if you are lucky
>> and spend a lot of time hunting for it.  But it is quite unlikely that
>> you will get much that is useful.
>>
>>   
> Ah right, well for the time being A lot of my friends have the same 
> data so loosing it is just inconvenient rather than a major no-go.
>>
>> The man page is out of date.  With reasonably recent kernel/mdadm you
>> can
>>   mdadm --grow /dev/mdX --add /dev/sdY
>>
>> To add a drive to a linear array.  You then need to grow the
>> filesystem of course.
>>
>> But yes:  A big linear array is good for scratch space, but I wouldn't
>> want to store data that I couldn't afford to lose.
>>
>> NeilBrown
>>   
> Cheers Neil, Once I can find enough hdd space else where to backup I 
> might play around with RAID0 etc I do plan to replace my odd size 
> drives with 500GB ones and RAID5 but I can't afford that at the moment.
>
>
> Thanks,
>
> Rich
>
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