On 10/20/2014 11:16 AM, Vickie CH wrote: > Hello all, > I have a question about how to calculate file size when mount a block > device from rbd image . > [Cluster information：] > 1.The cluster with 1 mon and 6 osds. Every osd is 1T. Total spaces is 5556G. > 2.rbd pool：replicated size 2 min_size 1. num = 128. Except rbd pool other > pools is empty. > > [Steps] > 1.On Linux client I use rbd command to create a 1.5T rbd image and format > it with ext4. > 2.Use dd command to create a 1.2T file. > #dd if=/dev/zero of=/mnt/ceph-mount/test12T bs=1M count=12288000 > 3.When dd finished the information shows "No space left on device". But > parted -l display the disk space is 1611G. Why does the system show space > not enough？ > > Is there something I misunderstand or wrong？ > Probably the rounding of GB and GiB. Keep in mind that 1.5TiB is 1.39TB and that ext4 also eats up space and reserves 5% for the superuser. > Best wishes, > Mika > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Wido den Hollander Ceph consultant and trainer 42on B.V. Phone: +31 (0)20 700 9902 Skype: contact42on _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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