[SOLVED] Ceph: calculate used disk space per pool

[cmonty14]

Hello,

I have defined a huge pool for database backups in Ceph.
Now I need to migrate these backups to another storage.
Therefore I must calculate the total disk space used by the backups.

I could display the RBDs of the relevant pool representing a database backup and summarize the RBD size with command rbd ls -l <pool-name>.
Or I could use the ouput of ceph df.

# ceph df
RAW STORAGE:
    CLASS          SIZE        AVAIL       USED        RAW USED     %RAW USED
    hdd            114 TiB     107 TiB     6.9 TiB      7.0 TiB          6.12
    hdd-strgbx     1.3 PiB     576 TiB     790 TiB      791 TiB         57.87
    nvme            23 TiB      23 TiB     1.4 GiB      9.4 GiB          0.04
    ssd             24 TiB      24 TiB     4.6 GiB       27 GiB          0.11
    TOTAL          1.5 PiB     730 TiB     797 TiB      798 TiB         52.24

POOLS:
    POOL                ID     PGS       STORED      OBJECTS     USED        %USED     MAX AVAIL
    hdb_backup          11     16384     263 TiB      69.13M     790 TiB     65.90       136 TiB
    hdd                 59      2048     1.5 TiB     647.01k     4.7 TiB      4.65        32 TiB
    cephfs_data         62        32     722 GiB     236.88k     2.1 TiB      2.17        32 TiB
    cephfs_metadata     63         8     727 MiB       2.08k     2.1 GiB         0        32 TiB
    nvme                65       128         0 B           0         0 B         0        11 TiB
    ssd                 66      1024         0 B           0         0 B         0        11 TiB
    rbd                 68         4         0 B           0         0 B         0        32 TiB

My question is:
Is the number POOL=hdb_backup, USED=790TB the sum of allocated space incl. replication factor?
Or must this number be deviced by replication factor to get the netto disk space used?

THX

 

[BenediktS]

Hello,

your hdb_backup pool has stored 263 TiB real user data . (you can see this in the "STORED" column)
I looks like you have a 3 replication setup, so the 263 TiB have a raw size of 790 TiB .

best regards
Benedikt

P.s.: In the "POOLS" section the "STORED" and "MAX AVAIL" column is user data size.