[ceph-users] Re: rbd persistent cache configuration

[Ilya Dryomov]

On Mon, Jan 8, 2024 at 10:43 PM Peter  wrote:
>
>  rbd --version
> ceph version 15.2.17 (8a82819d84cf884bd39c17e3236e0632ac146dc4) octopus 
> (stable)

Hi Peter,

The PWL cache was introduced in Pacific (16.2.z).

Thanks,

Ilya
___
ceph-users mailing list -- ceph-users@ceph.io
To unsubscribe send an email to ceph-users-le...@ceph.io

[ceph-users] Re: rbd persistent cache configuration

[Peter]

 rbd --version
ceph version 15.2.17 (8a82819d84cf884bd39c17e3236e0632ac146dc4) octopus (stable)
___
ceph-users mailing list -- ceph-users@ceph.io
To unsubscribe send an email to ceph-users-le...@ceph.io

[ceph-users] Re: rbd persistent cache configuration

[Ilya Dryomov]

On Sat, Jan 6, 2024 at 12:02 AM Peter  wrote:
>
> Thanks for ressponse! Yes, it is in use
>
> "watcher=10.1.254.51:0/1544956346 client.39553300 cookie=140244238214096" 
> this is indicating the client is connect the image.
> I am using fio perform write task on it.
>
> I guess it is the feature not enable correctly or setting somewhere 
> incorrect. Should I restart any process after modifying Ceph config?
>
> Any thought?

You haven't answered my question on versions.  Given "rbd: invalid
config key: ..." errors, it's very plausible that the cache is not
enabled correctly or even not supported at all.

Thanks,

Ilya
___
ceph-users mailing list -- ceph-users@ceph.io
To unsubscribe send an email to ceph-users-le...@ceph.io

[ceph-users] Re: rbd persistent cache configuration

[Peter]

Thanks for ressponse! Yes, it is in use

"watcher=10.1.254.51:0/1544956346 client.39553300 cookie=140244238214096" this 
is indicating the client is connect the image.
I am using fio perform write task on it.

I guess it is the feature not enable correctly or setting somewhere incorrect. 
Should I restart any process after modifying Ceph config?

Any thought?
___
ceph-users mailing list -- ceph-users@ceph.io
To unsubscribe send an email to ceph-users-le...@ceph.io

[ceph-users] Re: rbd persistent cache configuration

[Ilya Dryomov]

On Thu, Jan 4, 2024 at 4:41 PM Peter  wrote:
>
> I follow below document to setup image level rbd persistent cache,
> however I get error output while i using the command provide by the document.
> I have put my commands and descriptions below.
> Can anyone give some instructions? thanks in advance.
>
> https://docs.ceph.com/en/pacific/rbd/rbd-persistent-write-back-cache/
>
> https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/5/html/block_device_guide/ceph-block-devices#enabling-persistent-write-log-cache_block
> [https://access.redhat.com/webassets/avalon/g/shadowman-200.png]
> Chapter 2. Ceph block devices Red Hat Ceph Storage 5 | Red Hat Customer 
> Portal
> Access Red Hat’s knowledge, guidance, and support through your subscription.
> access.redhat.com
> I tried use host level client command, i got no error, however I won't be 
> able to get cache usage output.
> "ceph config set client rbd_persistent_cache_mode ssd
> ceph config set client rbd_plugins pwl_cache"
>
>
>
> [root@master-node1 ceph]# rbd info sas-pool/testdrive
> rbd image 'testdrive':
> size 40 GiB in 10240 objects
> order 22 (4 MiB objects)
> snapshot_count: 0
> id: 3de76a7e7c519
> block_name_prefix: rbd_data.3de76a7e7c519
> format: 2
> features: layering, exclusive-lock, object-map, fast-diff, 
> deep-flatten
> op_features:
> flags:
> create_timestamp: Thu Jun 29 02:03:41 2023
> access_timestamp: Thu Jun 29 07:19:40 2023
> modify_timestamp: Thu Jun 29 07:18:00 2023
>
> I check feature  exclusive-lock has been already enabled
> and I run following command get fault output.
> [root@master-node1 ceph]# rbd config image set sas-pool/testdrive 
> rbd_persistent_cache_mode ssd
> rbd: invalid config key: rbd_persistent_cache_mode
>
> [root@master-node1 ceph]# rbd config image set sas-pool/testdrive rbd_plugins 
> pwl_cache
> rbd: invalid config key: rbd_plugins

Hi Peter,

What is the output of "rbd --version" on this node?

Were "ceph config set client rbd_persistent_cache_mode ssd" and "ceph
config set client rbd_plugins pwl_cache" above ran on a different node?

>
> root@node1:~# rbd status sas-pool/testdrive
> Watchers:
> watcher=10.1.254.51:0/1544956346 client.39553300 
> cookie=140244238214096
>
>
> I hope to see the output include the persistent cache state like below:
>
> $ rbd status rbd/foo
> Watchers:
> watcher=10.10.0.102:0/1061883624 client.25496 cookie=140338056493088
> Persistent cache state:
> host: sceph9
> path: /mnt/nvme0/rbd-pwl.rbd.101e5824ad9a.pool
> size: 1 GiB
> mode: ssd
> stats_timestamp: Sun Apr 10 13:26:32 2022
> present: true   empty: falseclean: false
> allocated: 509 MiB
> cached: 501 MiB
> dirty: 338 MiB
> free: 515 MiB
> hits_full: 1450 / 61%
> hits_partial: 0 / 0%
> misses: 924
> hit_bytes: 192 MiB / 66%
> miss_bytes: 97 MiB

Normally, the output that you are expecting would be there only while
the image is opened.

Thanks,

Ilya
___
ceph-users mailing list -- ceph-users@ceph.io
To unsubscribe send an email to ceph-users-le...@ceph.io