Proxmox Ceph OSD Partition Created With Only 10GB


New Member
Jan 23, 2019
How do you define the Ceph OSD Disk Partition Size?
It always creates with only 10 GB usable space.
  • Disk size = 3.9 TB
  • Partition size = 3.7 TB
  • Using *ceph-disk prepare* and *ceph-disk activate* (See below)
  • OSD created but only with 10 GB, not 3.7 TB

Commands Used
    root@proxmox:~# ceph-disk prepare --cluster ceph --cluster-uuid fea02667-f17d-44fd-a4c2-a8e19d05ed51 --fs-type xfs /dev/sda4

    meta-data=/dev/sda4              isize=2048   agcount=4, agsize=249036799 blks
             =                       sectsz=512   attr=2, projid32bit=1
             =                       crc=1        finobt=1, sparse=0, rmapbt=0, reflink=0
    data     =                       bsize=4096   blocks=996147194, imaxpct=5
             =                       sunit=0      swidth=0 blks
    naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
    log      =internal log           bsize=4096   blocks=486399, version=2
             =                       sectsz=512   sunit=0 blks, lazy-count=1
    realtime =none                   extsz=4096   blocks=0, rtextents=0

    root@proxmox:~# ceph-disk activate /dev/sda4

    creating /var/lib/ceph/tmp/mnt.jyqJTM/keyring
    added entity osd.0 auth auth(auid = 18446744073709551615 key=AQAohgpdjwb3NRAAIrINUiXDWQ5iMWp4Ueah3Q== with 0 caps)
    got monmap epoch 3
    2019-06-19 19:59:54.006226 7f966e628e00 -1 bluestore(/var/lib/ceph/tmp/mnt.jyqJTM/block) _read_bdev_label failed to open /var/lib/ceph/tmp/mnt.jyqJTM/block: (2) No such file or directory
    2019-06-19 19:59:54.006285 7f966e628e00 -1 bluestore(/var/lib/ceph/tmp/mnt.jyqJTM/block) _read_bdev_label failed to open /var/lib/ceph/tmp/mnt.jyqJTM/block: (2) No such file or directory
    2019-06-19 19:59:55.668619 7f966e628e00 -1 created object store /var/lib/ceph/tmp/mnt.jyqJTM for osd.0 fsid fea02667-f17d-44fd-a4c2-a8e19d05ed51
    Created symlink /run/systemd/system/ → /lib/systemd/system/ceph-osd@.service.

    # Don't worry about my keys/IDs, its just a dev environment.

Disk Layout
    root@proxmox:~# fdisk -l
    Disk /dev/sda: 3.9 TiB, 4294967296000 bytes, 8388608000 sectors
    Device         Start        End    Sectors   Size Type
    /dev/sda1         34       2047       2014  1007K BIOS boot
    /dev/sda2       2048    1050623    1048576   512M EFI System
    /dev/sda3    1050624  419430400  418379777 199.5G Linux LVM
    /dev/sda4  419430408 8388607966 7969177559   3.7T Ceph OSD

Ceph OSD Disk Size Incorrect (10 GB not 1.7 TB)
    root@proxmox:~# ceph status
        pools:   0 pools, 0 pgs
        objects: 0 objects, 0B
        usage:   1.00GiB used, 9.00GiB / 10GiB avail


Full Install Details
If you want details on Proxmox install and creating Ceph OSD with partitions, read on...

  • Disk Size: 2TB NVMe (/dev/sda)
  • Operating system (Proxmox) installed with 200 GB and rest of disk is empty (1800 GB).
  • Once booted and in the web interface, create a cluster and join two hosts to ensure a green quorum status
  • Now do script below

Config Script
    # Install Ceph
    pveceph install
    # Configure Network (Just run on Primary Proxmox Server, your LAN network)
    pveceph init --network
    # Create Monitor
    pveceph createmon
    # View Disks Before
    sgdisk --print /dev/sda
    sgdisk --largest-new=4 --change-name="4:CephOSD" \
    --partition-guid=4:4fbd7e29-9d25-41b8-afd0-062c0ceff05d \
    --typecode=4:4fbd7e29-9d25-41b8-afd0-062c0ceff05d -- /dev/sda
    # View Disks After (Compare)
    sgdisk --print /dev/sda
    # Reboot for changes to be in affect
    # Note your cluster ID (fsid) at this point from the web interface 
    Datacenter > Server > Ceph

    # Prepare the Ceph OSD Disk, replace cluster-uuid with above fsid
    ceph-disk prepare --cluster ceph --cluster-uuid fea02667-f17d-44fd-a4c2-a8e19d05ed51 --fs-type xfs /dev/sda4

    # Activate the Ceph OSD Disk 
    ceph-disk activate /dev/sda4

    # Check Ceph OSD Disk Size
    ceph status

I have read posts highly recommending to use disks instead of partitions because of performance issues, I understand the warnings, but In my case I'm using NVMe SSD storage and accept any risks.


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