Re: cephfs full, 2/3 Raw capacity used

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Balancer just balance in Healthy mode.

The problem is that data is distributed without be balanced in their first
write, that cause unproperly data balanced across osd.

This problem only happens in CEPH, we are the same with 14.2.2, having to
change the weight manually.Because the balancer is a passive element of the
cluster.

I hope in next version we get a more aggressive balancer, like enterprises
storages that allow to fill up 95% storage (raw).

Regards


-----Mensaje original-----
De: ceph-users <ceph-users-bounces@xxxxxxxxxxxxxx> En nombre de Simon
Oosthoek
Enviado el: lunes, 26 de agosto de 2019 11:52
Para: Dan van der Ster <dan@xxxxxxxxxxxxxx>
CC: ceph-users <ceph-users@xxxxxxxxxxxxxx>
Asunto: Re:  cephfs full, 2/3 Raw capacity used

On 26-08-19 11:37, Dan van der Ster wrote:
> Thanks. The version and balancer config look good.
> 
> So you can try `ceph osd reweight osd.10 0.8` to see if it helps to 
> get you out of this.

I've done this and the next fullest 3 osds. This will take some time to
recover, I'll let you know when it's done.

Thanks,

/simon

> 
> -- dan
> 
> On Mon, Aug 26, 2019 at 11:35 AM Simon Oosthoek 
> <s.oosthoek@xxxxxxxxxxxxx> wrote:
>>
>> On 26-08-19 11:16, Dan van der Ster wrote:
>>> Hi,
>>>
>>> Which version of ceph are you using? Which balancer mode?
>>
>> Nautilus (14.2.2), balancer is in upmap mode.
>>
>>> The balancer score isn't a percent-error or anything humanly usable.
>>> `ceph osd df tree` can better show you exactly which osds are 
>>> over/under utilized and by how much.
>>>
>>
>> Aha, I ran this and sorted on the %full column:
>>
>>    81   hdd   10.81149  1.00000  11 TiB 5.2 TiB 5.1 TiB   4 KiB  14 GiB
>> 5.6 TiB 48.40 0.73  96     up                 osd.81
>>    48   hdd   10.81149  1.00000  11 TiB 5.3 TiB 5.2 TiB  15 KiB  14 GiB
>> 5.5 TiB 49.08 0.74  95     up                 osd.48
>> 154   hdd   10.81149  1.00000  11 TiB 5.5 TiB 5.4 TiB 2.6 GiB  15 GiB
>> 5.3 TiB 50.95 0.76  96     up                 osd.154
>> 129   hdd   10.81149  1.00000  11 TiB 5.5 TiB 5.4 TiB 5.1 GiB  16 GiB
>> 5.3 TiB 51.33 0.77  96     up                 osd.129
>>    42   hdd   10.81149  1.00000  11 TiB 5.6 TiB 5.5 TiB 2.6 GiB  14 GiB
>> 5.2 TiB 51.81 0.78  96     up                 osd.42
>> 122   hdd   10.81149  1.00000  11 TiB 5.7 TiB 5.6 TiB  16 KiB  14 GiB
>> 5.1 TiB 52.47 0.79  96     up                 osd.122
>> 120   hdd   10.81149  1.00000  11 TiB 5.7 TiB 5.6 TiB 2.6 GiB  15 GiB
>> 5.1 TiB 52.92 0.79  95     up                 osd.120
>>    96   hdd   10.81149  1.00000  11 TiB 5.8 TiB 5.7 TiB 2.6 GiB  15 GiB
>> 5.0 TiB 53.58 0.80  96     up                 osd.96
>>    26   hdd   10.81149  1.00000  11 TiB 5.8 TiB 5.7 TiB  20 KiB  15 GiB
>> 5.0 TiB 53.68 0.80  97     up                 osd.26
>> ...
>>     6   hdd   10.81149  1.00000  11 TiB 8.3 TiB 8.2 TiB  88 KiB  18 GiB
>> 2.5 TiB 77.14 1.16  96     up                 osd.6
>>    16   hdd   10.81149  1.00000  11 TiB 8.4 TiB 8.3 TiB  28 KiB  18 GiB
>> 2.4 TiB 77.56 1.16  95     up                 osd.16
>>     0   hdd   10.81149  1.00000  11 TiB 8.6 TiB 8.4 TiB  48 KiB  17 GiB
>> 2.2 TiB 79.24 1.19  96     up                 osd.0
>> 144   hdd   10.81149  1.00000  11 TiB 8.6 TiB 8.5 TiB 2.6 GiB  18 GiB
>> 2.2 TiB 79.57 1.19  95     up                 osd.144
>> 136   hdd   10.81149  1.00000  11 TiB 8.6 TiB 8.5 TiB  48 KiB  17 GiB
>> 2.2 TiB 79.60 1.19  95     up                 osd.136
>>    63   hdd   10.81149  1.00000  11 TiB 8.6 TiB 8.5 TiB 2.6 GiB  17 GiB
>> 2.2 TiB 79.60 1.19  95     up                 osd.63
>> 155   hdd   10.81149  1.00000  11 TiB 8.6 TiB 8.5 TiB   8 KiB  19 GiB
>> 2.2 TiB 79.85 1.20  95     up                 osd.155
>>    89   hdd   10.81149  1.00000  11 TiB 8.7 TiB 8.5 TiB  12 KiB  20 GiB
>> 2.2 TiB 80.04 1.20  96     up                 osd.89
>> 106   hdd   10.81149  1.00000  11 TiB 8.8 TiB 8.7 TiB  64 KiB  19 GiB
>> 2.0 TiB 81.38 1.22  96     up                 osd.106
>>    94   hdd   10.81149  1.00000  11 TiB 9.0 TiB 8.9 TiB     0 B  19 GiB
>> 1.8 TiB 83.53 1.25  96     up                 osd.94
>>    33   hdd   10.81149  1.00000  11 TiB 9.1 TiB 9.0 TiB  44 KiB  19 GiB
>> 1.7 TiB 84.40 1.27  96     up                 osd.33
>>    15   hdd   10.81149  1.00000  11 TiB  10 TiB 9.8 TiB  16 KiB  20 GiB
>> 877 GiB 92.08 1.38  96     up                 osd.15
>>    53   hdd   10.81149  1.00000  11 TiB  10 TiB  10 TiB 2.6 GiB  20 GiB
>> 676 GiB 93.90 1.41  96     up                 osd.53
>>    51   hdd   10.81149  1.00000  11 TiB  10 TiB  10 TiB 2.6 GiB  20 GiB
>> 666 GiB 93.98 1.41  96     up                 osd.51
>>    10   hdd   10.81149  1.00000  11 TiB  10 TiB  10 TiB  40 KiB  22 GiB
>> 552 GiB 95.01 1.42  97     up                 osd.10
>>
>> So the fullest one is at 95.01%, the emptiest one at 48.4%, so 
>> there's some balancing to be done.
>>
>>> You might be able to manually fix things by using `ceph osd reweight 
>>> ...` on the most full osds to move data elsewhere.
>>
>> I'll look into this, but I was hoping that the balancer module would 
>> take care of this...
>>
>>>
>>> Otherwise, in general, its good to setup monitoring so you notice 
>>> and take action well before the osds fill up.
>>
>> Yes, I'm still working on this, I want to add some checks to our 
>> check_mk+icinga setup using native plugins, but my python skills are 
>> not quite up to the task, at least, not yet ;-)
>>
>> Cheers
>>
>> /Simon
>>
>>>
>>> Cheers, Dan
>>>
>>> On Mon, Aug 26, 2019 at 11:09 AM Simon Oosthoek 
>>> <s.oosthoek@xxxxxxxxxxxxx> wrote:
>>>>
>>>> Hi all,
>>>>
>>>> we're building up our experience with our ceph cluster before we 
>>>> take it into production. I've now tried to fill up the cluster with 
>>>> cephfs, which we plan to use for about 95% of all data on the cluster.
>>>>
>>>> The cephfs pools are full when the cluster reports 67% raw capacity 
>>>> used. There are 4 pools we use for cephfs data, 3-copy, 4-copy, EC 
>>>> 8+3 and EC 5+7. The balancer module is turned on and `ceph balancer 
>>>> eval` gives `current cluster score 0.013255 (lower is better)`, so 
>>>> well within the default 5% margin. Is there a setting we can tweak 
>>>> to increase the usable RAW capacity to say 85% or 90%, or is this 
>>>> the most we can expect to store on the cluster?
>>>>
>>>> [root@cephmon1 ~]# ceph df
>>>> RAW STORAGE:
>>>>        CLASS     SIZE        AVAIL       USED        RAW USED     %RAW
USED
>>>>        hdd       1.8 PiB     605 TiB     1.2 PiB      1.2 PiB
66.71
>>>>        TOTAL     1.8 PiB     605 TiB     1.2 PiB      1.2 PiB
66.71
>>>>
>>>> POOLS:
>>>>        POOL                    ID     STORED      OBJECTS     USED
>>>> %USED      MAX AVAIL
>>>>        cephfs_data              1     111 MiB      79.26M     1.2 GiB
>>>> 100.00           0 B
>>>>        cephfs_metadata          2      52 GiB       4.91M      52 GiB
>>>> 100.00           0 B
>>>>        cephfs_data_4copy        3     106 TiB      46.36M     428 TiB
>>>> 100.00           0 B
>>>>        cephfs_data_3copy        8      93 TiB      42.08M     282 TiB
>>>> 100.00           0 B
>>>>        cephfs_data_ec83        13     106 TiB      50.11M     161 TiB
>>>> 100.00           0 B
>>>>        rbd                     14      21 GiB       5.62k      63 GiB
>>>> 100.00           0 B
>>>>        .rgw.root               15     1.2 KiB           4       1 MiB
>>>> 100.00           0 B
>>>>        default.rgw.control     16         0 B           8         0 B
>>>>        0           0 B
>>>>        default.rgw.meta        17       765 B           4       1 MiB
>>>> 100.00           0 B
>>>>        default.rgw.log         18         0 B         207         0 B
>>>>        0           0 B
>>>>        scbench                 19     133 GiB      34.14k     400 GiB
>>>> 100.00           0 B
>>>>        cephfs_data_ec57        20     126 TiB      51.84M     320 TiB
>>>> 100.00           0 B
>>>> [root@cephmon1 ~]# ceph balancer eval current cluster score 
>>>> 0.013255 (lower is better)
>>>>
>>>>
>>>> Being full at 2/3 Raw used is a bit too "pretty" to be accidental, 
>>>> it seems like this could be a parameter for cephfs, however, I 
>>>> couldn't find anything like this in the documentation for Nautilus.
>>>>
>>>>
>>>> The logs in the dashboard show this:
>>>> 2019-08-26 11:00:00.000630
>>>> [ERR]
>>>> overall HEALTH_ERR 3 backfillfull osd(s); 1 full osd(s); 12 pool(s) 
>>>> full
>>>>
>>>> 2019-08-26 10:57:44.539964
>>>> [INF]
>>>> Health check cleared: POOL_BACKFILLFULL (was: 12 pool(s) 
>>>> backfillfull)
>>>>
>>>> 2019-08-26 10:57:44.539944
>>>> [WRN]
>>>> Health check failed: 12 pool(s) full (POOL_FULL)
>>>>
>>>> 2019-08-26 10:57:44.539926
>>>> [ERR]
>>>> Health check failed: 1 full osd(s) (OSD_FULL)
>>>>
>>>> 2019-08-26 10:57:44.539899
>>>> [WRN]
>>>> Health check update: 3 backfillfull osd(s) (OSD_BACKFILLFULL)
>>>>
>>>> 2019-08-26 10:00:00.000088
>>>> [WRN]
>>>> overall HEALTH_WARN 4 backfillfull osd(s); 12 pool(s) backfillfull
>>>>
>>>> So it seems that ceph is completely stuck at 2/3 full, while we 
>>>> anticipated being able to fill up the cluster to at least 85-90% of 
>>>> the raw capacity. Or at least so that we would keep a functioning 
>>>> cluster when we have a single osd node fail.
>>>>
>>>> Cheers
>>>>
>>>> /Simon
>>>> _______________________________________________
>>>> ceph-users mailing list
>>>> ceph-users@xxxxxxxxxxxxxx
>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>

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