Results 1 to 6 of 6

Thread: Issue with LVM snapshot based backups

  1. #1

    Default Issue with LVM snapshot based backups

    Hi,

    We were very excited when we discovered ZRM and it's snapshot feature. After we configured it to run a snapshot based backup we ran into the issue below. Why is that?


    schedule:INFO: ZRM for MySQL Community Edition - version 2.1
    Logging to /var/log/mysql-zrm/mysql-zrm-scheduler.log
    backup:INFO: ZRM for MySQL Community Edition - version 2.1
    dailyrun:backup:INFO: START OF BACKUP
    dailyrun:backup:INFO: PHASE START: Initialization
    dailyrun:backup:WARNING: last backup directory is not valid
    dailyrun:backup:INFO: backup-set=dailyrun
    dailyrun:backup:INFO: backup-date=20090717093737
    dailyrun:backup:INFO: mysql-server-os=Linux/Unix
    dailyrun:backup:INFO: backup-type=regular
    dailyrun:backup:INFO: host=localhost
    dailyrun:backup:INFO: backup-date-epoch=1247816257
    dailyrun:backup:INFO: mysql-zrm-version=ZRM for MySQL Community Edition - version 2.1
    dailyrun:backup:INFO: mysql-version=5.0.45-log
    dailyrun:backup:INFO: backup-directory=/var/lib/mysql-zrm/dailyrun/20090717093737
    dailyrun:backup:INFO: backup-level=0
    dailyrun:backup:INFO: backup-mode=raw
    dailyrun:backup:INFO: PHASE END: Initialization
    dailyrun:backup:INFO: PHASE START: Running pre backup plugin
    dailyrun:backup:INFO: PHASE END: Running pre backup plugin
    dailyrun:backup:INFO: PHASE START: Flushing logs
    dailyrun:backup:INFO: PHASE END: Flushing logs
    dailyrun:backup:INFO: PHASE START: Creating snapshot based backup
    dailyrun:backup:INFO: File Position Binlog_Do_DB Binlog_Ignore_DB
    bin.000011 98
    mount: special device /dev/VolGroup00/zrmfrMG27nVdr does not exist
    mount of /dev/VolGroup00/zrmfrMG27nVdr on /var/lib/mysql-zrm/dailyrun/20090717093737/ZRM_MOUNTS/zrmfrMG27nVdr failed
    dailyrun:backup:WARNING: Snapshot failed
    dailyrun:backup:WARNING: Unable to use snapshot
    dailyrun:backup:WARNING: Output of command: 'remove-snapshot' is {
    One or more specified logical volume(s) not found.
    remove of /dev/VolGroup00/zrmfrMG27nVdr failed
    }
    dailyrun:backup:WARNING: remove snapshot failed. Command used is /usr/share/mysql-zrm/plugins/lvm-snapshot.pl --action remove-snapshot --dev "/dev/VolGroup00/zrmfrMG27nVdr" > /tmp/A8eOTcNBoF 2>&1
    dailyrun:backup:INFO: PHASE END: Creating snapshot based backup

  2. #2
    Join Date
    Oct 2005
    Posts
    1,559

    Default

    If you do lvdisplay in the volume group, do you still see the snapshot?

    Do you see lvm errors in /var/log/messages?

    Paddy

  3. #3

    Default

    Thanks for your quick reply!

    No, there is no snapshot.

    And sorry, no lvm errors in /var/log/messages.

    Do I need to setup things in a specific way? I have not created a MySQL data dir as a seperate logical volume or so. On the test server:

    # df -h
    Filesystem Size Used Avail Use% Mounted on
    /dev/mapper/VolGroup00-LogVol00
    143G 7.2G 128G 6% /
    /dev/mapper/ddf1_systemp1
    190M 13M 169M 7% /boot
    tmpfs 505M 0 505M 0% /dev/shm

    # vgdisplay
    --- Volume group ---
    VG Name VolGroup00
    System ID
    Format lvm2
    Metadata Areas 1
    Metadata Sequence No 3
    VG Access read/write
    VG Status resizable
    MAX LV 0
    Cur LV 2
    Open LV 2
    Max PV 0
    Cur PV 1
    Act PV 1
    VG Size 148.69 GB
    PE Size 32.00 MB
    Total PE 4758
    Alloc PE / Size 4757 / 148.66 GB
    Free PE / Size 1 / 32.00 MB
    VG UUID XwQMza-H0bG-g3Eo-iIpC-trTL-FOrj-EYroPe

    # lvdisplay
    --- Logical volume ---
    LV Name /dev/VolGroup00/LogVol00
    VG Name VolGroup00
    LV UUID IchVAu-20tl-AW2p-p2pB-oH9j-2ajF-jVS4EV
    LV Write Access read/write
    LV Status available
    # open 1
    LV Size 146.72 GB
    Current LE 4695
    Segments 1
    Allocation inherit
    Read ahead sectors 0
    Block device 253:3

    --- Logical volume ---
    LV Name /dev/VolGroup00/LogVol01
    VG Name VolGroup00
    LV UUID a38lFt-DOmV-RDDv-YEBU-6USz-G2Hf-NL9AVP
    LV Write Access read/write
    LV Status available
    # open 1
    LV Size 1.94 GB
    Current LE 62
    Segments 1
    Allocation inherit
    Read ahead sectors 0
    Block device 253:4
    Last edited by JUnkie; July 20th, 2009 at 05:48 AM.

  4. #4
    Join Date
    Oct 2005
    Posts
    58

    Default

    It is good idea to put MySQL data directory and logs in separate logical volume (not root logical volume). You can get snapshot errors/poor performance if you are using root logical volume and use lvm snapshot method for full backups.

    Paddy

  5. #5

    Default

    JUnkie , if you see output of vgdisplay so says you do not have Free PE. So please add some space to your VolumeGroup then try it.

  6. #6

    Default

    Quote Originally Posted by abhishek View Post
    JUnkie , if you see output of vgdisplay so says you do not have Free PE. So please add some space to your VolumeGroup then try it.
    I also don't have any Free PE, how do I add them?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •