Re: [MooseFS-Users] Marking disc for removal - chunkserver gets no more chunks

[Piotr R. K. <pio...@mo...>]

Hello Wolfgang,

> So when my drive has no more chunks on it is it save to comment out the line in mfshdd.cfg

Yes, when all chunks are moved out from this drive
(in MFS CGI next to this drive, in column "chunks" 0 is shown),
you can safely comment this drive out in mfshdd.cfg.


Best regards,

-- 
Piotr Robert Konopelko
MooseFS Technical Support Engineer | moosefs.com <https://moosefs.com/>
> On 22 Jan 2016, at 11:13 AM, Wolfgang <moo...@wo...> wrote:
> 
> Hi Piotr Robert!
> 
> I think using "<" moves the data - as my drive marked is slowly decreasing in chunk-count.
> Also syslogs says so:
> ---
> move chunk /data/disc1/mfschunk/ -> /data/disc2/mfschunk/ (chunk: 0000000000026440_00000001)
> ---
> 
> So when my drive has no more chunks on it is it save to comment out the line in mfshdd.cfg or should this drive then be marked with * and waited for "READY" in MFS CGI ?
> 
> 
> Thanks for your always detailed answers!
> Greetings
> Wolfgang
> 
> 
> 
> On 2016-01-21 23:55, Piotr Robert Konopelko wrote:
>> Hi Wolfgang,
>> 
>>> On 21 Jan 2016, at 10:55 PM, Wolfgang < <mailto:moo...@wo...>moo...@wo... <mailto:moo...@wo...>> wrote:
>>> 
>>> Hi Piotr Robert!
>>> 
>>> When using < or > should I use the * also?
>> 
>> No, you shouldn't use both * and (< or >)
>> 
>>> like:
>>> <* /data/disc1
>>> when disc1 should be removed in near future?
>> 
>> No
>> 
>>> or either
>>> * /data/disc1
>>> < /data/disc1
>> 
>> Yes
>> 
>>> So to make this clear:
>>> data from discs marked with * will be moved anywhere in the cluster
>> 
>> Yes
>> 
>>> data from discs marked with < will be moved to other discs (or if set only to the ">" marked discs) on the same chunkserver
>> 
>> Yes
>> 
>>> So I guess using * or < but not both - am I right?
>> 
>> Yes :)
>> 
>> One more note:
>> When you use * before disk path, data (chunks) are not moved, they are replicated,
>> so an extra copy of chunks from such disk marked for removal with * is made by MFS.
>> (You can see a lot of overgoal chunks in blue on all chunks state matrix in MFS CGI and when
>> you disconnect such drive when it is "ready", no undergoal chunks should be visible,
>> only most of overgoal chunks should disappear from chunks matrix).
>> 
>> I'm not sure at this moment, but as far as I remember, when you use "<" (and/or ">"),
>> data (chunks) are not replicated, they are moved to another drive(s) on the same machine.
>> 
>> I didn't used / tested this feature ("<" and ">") for a long time, so I'm not sure here whether
>> it replicates the data or moves it, but as I said above, probably it moves.
>> (I can perform a test when I'll be at the office - most possibly I can do it tomorrow's
>> afternoon, so probably you'll be faster than me :)
>> 
>> 
>>> Thank you & Greetings
>>> Wolfgang
>> 
>> 
>> Best,
>> 
>> -- 
>> Piotr Robert Konopelko
>> MooseFS Technical Support Engineer | moosefs.com <https://moosefs.com/>