If you go down just a little farther you'll see the settings that you put
into your ceph.conf under the osd section (although I'd probably do
global). That's where the OSDs get the settings from. As a note, once
these are set, future writes will be compressed (if they match the
compression settings which you can see there about minimum ratios, blob
sizes, etc). To compress current data, you need to re-write it.
On Fri, Oct 12, 2018 at 10:41 AM Frank Schilder <fr...@dtu.dk> wrote:
> Hi David,
>
> thanks for your quick answer. When I look at both references, I see
> exactly the same commands:
>
> ceph osd pool set {pool-name} {key} {value}
>
> where on one page only keys specific for compression are described. This
> is the command I found and used. However, I can't see any compression
> happening. If you know about something else than "ceph osd pool set" -
> commands, please let me know.
>
> Best regards,
>
> =================
> Frank Schilder
> AIT Risø Campus
> Bygning 109, rum S14
>
> ________________________________________
> From: David Turner <drakonst...@gmail.com>
> Sent: 12 October 2018 15:47:20
> To: Frank Schilder
> Cc: ceph-users@lists.ceph.com
> Subject: Re: [ceph-users] bluestore compression enabled but no data
> compressed
>
> It's all of the settings that you found in your first email when you
> dumped the configurations and such.
> http://docs.ceph.com/docs/master/rados/configuration/bluestore-config-ref/#inline-compression
>
> On Fri, Oct 12, 2018 at 7:36 AM Frank Schilder <fr...@dtu.dk<mailto:
> fr...@dtu.dk>> wrote:
> Hi David,
>
> thanks for your answer. I did enable compression on the pools as described
> in the link you sent below (ceph osd pool set sr-fs-data-test
> compression_mode aggressive, I also tried force to no avail). However, I
> could not find anything on enabling compression per OSD. Could you possibly
> provide a source or sample commands?
>
> Thanks and best regards,
>
> =================
> Frank Schilder
> AIT Risø Campus
> Bygning 109, rum S14
>
> ________________________________________
> From: David Turner <drakonst...@gmail.com<mailto:drakonst...@gmail.com>>
> Sent: 09 October 2018 17:42
> To: Frank Schilder
> Cc: ceph-users@lists.ceph.com<mailto:ceph-users@lists.ceph.com>
> Subject: Re: [ceph-users] bluestore compression enabled but no data
> compressed
>
> When I've tested compression before there are 2 places you need to
> configure compression. On the OSDs in the configuration settings that you
> mentioned, but also on the [1] pools themselves. If you have the
> compression mode on the pools set to none, then it doesn't matter what the
> OSDs configuration is and vice versa unless you are using the setting of
> force. If you want to default compress everything, set pools to passive
> and osds to aggressive. If you want to only compress specific pools, set
> the osds to passive and the specific pools to aggressive. Good luck.
>
>
> [1]
> http://docs.ceph.com/docs/mimic/rados/operations/pools/#set-pool-values
>
> On Tue, Sep 18, 2018 at 7:11 AM Frank Schilder <fr...@dtu.dk<mailto:
> fr...@dtu.dk><mailto:fr...@dtu.dk<mailto:fr...@dtu.dk>>> wrote:
> I seem to have a problem getting bluestore compression to do anything. I
> followed the documentation and enabled bluestore compression on various
> pools by executing "ceph osd pool set <pool-name> compression_mode
> aggressive". Unfortunately, it seems like no data is compressed at all. As
> an example, below is some diagnostic output for a data pool used by a
> cephfs:
>
> [root@ceph-01 ~]# ceph --version
> ceph version 12.2.7 (3ec878d1e53e1aeb47a9f619c49d9e7c0aa384d5) luminous
> (stable)
>
> All defaults are OK:
>
> [root@ceph-01 ~]# ceph --show-config | grep compression
> [...]
> bluestore_compression_algorithm = snappy
> bluestore_compression_max_blob_size = 0
> bluestore_compression_max_blob_size_hdd = 524288
> bluestore_compression_max_blob_size_ssd = 65536
> bluestore_compression_min_blob_size = 0
> bluestore_compression_min_blob_size_hdd = 131072
> bluestore_compression_min_blob_size_ssd = 8192
> bluestore_compression_mode = none
> bluestore_compression_required_ratio = 0.875000
> [...]
>
> Compression is reported as enabled:
>
> [root@ceph-01 ~]# ceph osd pool ls detail
> [...]
> pool 24 'sr-fs-data-test' erasure size 8 min_size 7 crush_rule 10
> object_hash rjenkins pg_num 50 pgp_num 50 last_change 7726 flags
> hashpspool,ec_overwrites stripe_width 24576 compression_algorithm snappy
> compression_mode aggressive application cephfs
> [...]
>
> [root@ceph-01 ~]# ceph osd pool get sr-fs-data-test compression_mode
> compression_mode: aggressive
> [root@ceph-01 ~]# ceph osd pool get sr-fs-data-test compression_algorithm
> compression_algorithm: snappy
>
> We dumped a 4Gib file with dd from /dev/zero. Should be easy to compress
> with excellent ratio. Search for a PG:
>
> [root@ceph-01 ~]# ceph pg ls-by-pool sr-fs-data-test
> PG_STAT OBJECTS MISSING_ON_PRIMARY DEGRADED MISPLACED UNFOUND BYTES
> LOG DISK_LOG STATE STATE_STAMP VERSION REPORTED UP
> UP_PRIMARY ACTING ACTING_PRIMARY
> LAST_SCRUB SCRUB_STAMP LAST_DEEP_SCRUB DEEP_SCRUB_STAMP
> 24.0 15 0 0 0 0 62914560
> 77 77 active+clean 2018-09-14 01:07:14.593007 7698'77 7735:142
> [53,47,36,30,14,55,57,5] 53 [53,47,36,30,14,55,57,5]
> 53 7698'77 2018-09-14 01:07:14.592966 0'0 2018-09-11
> 08:06:29.309010
>
> There is about 250MB data on the primary OSD, but noting seems to be
> compressed:
>
> [root@ceph-07 ~]# ceph daemon osd.53 perf dump | grep blue
> [...]
> "bluestore_allocated": 313917440,
> "bluestore_stored": 264362803,
> "bluestore_compressed": 0,
> "bluestore_compressed_allocated": 0,
> "bluestore_compressed_original": 0,
> [...]
>
> Just to make sure, I checked one of the objects' contents:
>
> [root@ceph-01 ~]# rados ls -p sr-fs-data-test
> 10000000004.0000039c
> [...]
> 10000000004.0000039f
>
> It is 4M chunks ...
> [root@ceph-01 ~]# rados -p sr-fs-data-test stat 10000000004.0000039f
> sr-fs-data-test/10000000004.0000039f mtime 2018-09-11 14:39:38.000000,
> size 4194304
>
> ... with all zeros:
>
> [root@ceph-01 ~]# rados -p sr-fs-data-test get 10000000004.0000039f obj
>
> [root@ceph-01 ~]# hexdump -C obj
> 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> |................|
> *
> 00400000
>
> All as it should be, except for compression. Am I overlooking something?
>
> Best regards,
>
> =================
> Frank Schilder
> AIT Risø Campus
> Bygning 109, rum S14
> _______________________________________________
> ceph-users mailing list
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> ceph-users@lists.ceph.com<mailto:ceph-users@lists.ceph.com>>
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>
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