CephNotes

Some notes about Ceph
Laurent Barbe @CCM Benchmark

Samba Shadow_copy and Ceph RBD

I add script to create snapshot on rbd for use with samba shadow_copy2. For more details go on https://github.com/ksperis/autosnap-rbd-shadow-copy

 How to use :

Before you need to have ceph cluster running and samba installed.

Verify admin access to the ceph cluster : (should not return error)

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$ rbd ls

Get the script :

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$ mkdir -p /etc/ceph/scripts/
$ cd /etc/ceph/scripts/
$ wget https://raw.github.com/ksperis/autosnap-rbd-shadow-copy/master/autosnap.conf
$ wget https://raw.github.com/ksperis/autosnap-rbd-shadow-copy/master/autosnap.sh
$ chmod +x autosnap.sh

Create a block device :

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$ rbd create myshare --size=1024
$ echo "myshare" >> /etc/ceph/rbdmap
$ /etc/init.d/rbdmap reload
[ ok ] Starting RBD Mapping: rbd/myshare.
[ ok ] Mounting all filesystems...done.

Format the block device :

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$ mkfs.xfs /dev/rbd/rbd/myshare
log stripe unit (4194304 bytes) is too large (maximum is 256KiB)
log stripe unit adjusted to 32KiB
meta-data=/dev/rbd/rbd/myshare   isize=256    agcount=9, agsize=31744 blks
         =                       sectsz=512   attr=2, projid32bit=0
data     =                       bsize=4096   blocks=262144, imaxpct=25
         =                       sunit=1024   swidth=1024 blks
naming   =version 2              bsize=4096   ascii-ci=0
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=8 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Mount the share :

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$ mkdir /myshare
$ echo "/dev/rbd/rbd/myshare /myshare xfs defaults 0 0" >> /etc/fstab
$ mount /myshare

Add this section in your /etc/samba/smb.conf :

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[myshare]
    path = /myshare
    writable = yes
  vfs objects = shadow_copy2
  shadow:snapdir = .snapshots
  shadow:sort = desc

Reload samba

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$ /etc/init.d/samba reload

Create snapshot directory and run the script :

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$ mkdir -p /myshare/.snapshots
$ /etc/ceph/scripts/autosnap.sh
* Create snapshot for myshare: @GMT-2013.08.09-10.16.10-autosnap
synced, no cache, snapshot created.
* Shadow Copy to mount for rbd/myshare :
GMT-2013.08.09-10.14.44

Verify that the first snapshot is correctly mount :

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$ mount | grep myshare
/dev/rbd1 on /myshare type xfs (rw,relatime,attr2,inode64,sunit=8192,swidth=8192,noquota)
/dev/rbd2 on /myshare/.snapshots/@GMT-2013.08.09-10.14.44 type xfs (ro,relatime,nouuid,norecovery,attr2,inode64,sunit=8192,swidth=8192,noquota)

Also, you can add this on crontab to run everyday the script :

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$ echo "00 0    * * *   root    /bin/bash /etc/ceph/scripts/autosnap.sh" >> /etc/crontab

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