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

[Wolfgang <moo...@wo...>]

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 <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>