Hi Jeremy

Thanks for the response! Do you need a maxed out lsblk or just our general
setup? Here's a happy (not 100% metadata) box:

[15:13:09] root@kubecltest-0:/home/company# lsblk
NAME                        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
xvda                        202:0    0  512M  0 disk
└─xvda1                     202:1    0  511M  0 part /boot
xvdb                        202:16   0   20G  0 disk /
xvdc                        202:32   0   20G  0 disk
├─docker-docker--pool_tmeta 253:0    0   24M  0 lvm
│ └─docker-docker--pool     253:2    0 19.6G  0 lvm
└─docker-docker--pool_tdata 253:1    0 19.6G  0 lvm
  └─docker-docker--pool     253:2    0 19.6G  0 lvm
xvdd                        202:48   0    1G  0 disk [SWAP]


[15:13:22] root@kubecltest-0:/home/company# docker info
Containers: 1
Images: 322
Storage Driver: devicemapper
 Pool Name: docker-docker--pool
 Pool Blocksize: 524.3 kB
 Backing Filesystem: extfs
 Data file:
 Metadata file:
 Data Space Used: 2.856 GB
 Data Space Total: 21.04 GB
 Data Space Available: 18.18 GB
 Metadata Space Used: 4.42 MB
 Metadata Space Total: 25.17 MB
 Metadata Space Available: 20.75 MB
 Udev Sync Supported: true
 Deferred Removal Enabled: false
 Library Version: 1.02.107-RHEL7 (2015-12-01)
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 3.10.0-327.10.1.el7.x86_64
Operating System: CentOS Linux 7 (Core)
CPUs: 1
Total Memory: 989.3 MiB
Name: kubecltest-0
ID: UTBH:QETO:VI2M:E2FI:I62U:CICM:VR74:SW3U:LSUZ:LEKY:BRTW:TQNI
WARNING: bridge-nf-call-ip6tables is disabled

Any more info just let me know.

Thanks
Andy

On 22 July 2016 at 13:33, Jeremy Eder <[email protected]> wrote:

> +Vivek
>
>
> I don't know the exact bug here, but one possibility is that since you've
> disabled the auto-extend, that it's leaving the metadata size at it's
> default? There is indeed a relationship between the two and I did a lot of
> testing around it to make sure we were not going to hit what you've hit :-/
>  At that time however, we did not have the auto-extend feature.
>
> So I think you may have found a situation where we need METADATA_SIZE=N
> but you said you set that at 2%?
> Can you paste the output of "docker info"  and "lsblk" please?
>
> From April 2015 when I last looked at this, the tests ran were to start
> 1000 httpd containers and measure the thinpool used size.  Here:
>
>
> ​
>
> So, for 1000 rhel7+httpd containers, on-disk it was using about 3GB
> (left-Y-axis).
> And the metadata consumed was about 50MB (right-Y-axis).
>
> You can see we concluded to set metadata @ 0.1% of the data partition
> size, which in the case:
>
> https://github.com/projectatomic/docker-storage-setup/blob/master/docker-storage-setup.sh#L220
>
> I am wondering what your docker info will say.
>
>
>
>
>
>
>
> On Fri, Jul 22, 2016 at 8:08 AM, Andrew Smith <[email protected]>
> wrote:
>
>> Hi
>>
>> We've been using docker-storage-setup (
>> https://github.com/projectatomic/docker-storage-setup) to set up our
>> CentOS LVM volumes.
>>
>> Because our block devices are fairly small and our containers don't write
>> data inside them (and we hit issues with resizes being very slow) we have a
>> static setup:
>>
>> AUTO_EXTEND_POOL=False
>> DATA_SIZE=98%VG
>>
>> The intention is to just create the lv as big as we can up front, because
>> we don't need that space for anything else. We leave 2% for metadata.
>>
>> However - we're running in to a problem, where our metadata volume is
>> hitting 100% before out data volume gets close (sometimes, 60%). We're
>> deploying kubernetes on these boxes, which garbage collects based on data
>> usage not metadata usage, so we are often hitting the 100% and taking out
>> boxes.
>>
>> What I'm struggling to understand is how much metadata a docker image or
>> docker container uses. If I can find that out I can figure out a good
>> data:metadata ratio. Is there a way for me to discover this?
>>
>> Or, as I suspect, am I missing something here?
>>
>> Thanks
>> --
>> Andy Smith
>> http://andrewmichaelsmith.com | @bingleybeep
>>
>>
>
>
> --
>
> -- Jeremy Eder
>



-- 
Andy Smith
http://andrewmichaelsmith.com | @bingleybeep

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