Re: [Moosefs-users] Chunks

[randall <ra...@so...>]

On 03/03/2011 11:06 PM, Ricardo J. Barberis wrote:
> El Jue 03 Marzo 2011, Steve escribió:
>> In your first scenario why wouldn't you just mirror the drives ?
> 
> With only one chunkserver? Yes.

thanks,

understand that if you have a single server setup just normail Raid (10)
would be the better approach in this case.

but i need some intermediate solution, working on a cash/space/equipment
strapped hobby project where we start out with 1 server and we are bound
to to end up with more chunk servers eventually.

it is not ideal but having goal=2 using a single server (temporarily)
saves the hassle of rebuilding the architecture of the setup in a later
stage and is at least better than goal=1

anyway, in case someone might be interested, it is doable using
virtualisation (linux VServer) using 2 chunk servers as a virtual
machine with its own IP and mounting half the amount of disks in each.

Again, this does not save you from machine failure and is not the
best/most efficient mirroring solution in itself but it does save you
somewhat from single disk failure.




> 
>> -------Original Message-------
>>
>> From: randall
>> Date: 03/03/2011 10:14:00
>> To: moo...@li...
>> Subject: Re: [Moosefs-users] Chunks
>>
>> On 03/02/2011 11:40 AM, Michal Borychowski wrote:
>>> The main purpose of MooseFS system is security not the space savings. And
>>> solution with RAID6 is not that secure. We generally advise not to use
>>> any RAIDs and using at least goal=2.
>>
>> Wondering about this.
>>
>> when no raid and goal=2, this would mean when using multiple disks per
>> server that each disk would be a seperate chunk location.
>>
>> Can see the use of this when you use 1 single server as each copy would
>> reside on 2 seperate disks so you are somewhat protected against disk
>> failure.
>>
>> but when you have 2 servers with each 12 disks (24 chunk locations),
>> does each chunk reside on 2 seperate servers giving protection against
>> server failure?
>>
>> did read somewhere there is work done on "location awareness" spreading
>> each chunks over racks
>>
>> Randall
>