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920
October 24th, 2013 18:00
File system size displayed with Unisphere
I created new file system.(fs name is 1TB)
In Unisphere, Used capacity is 15.6 GB without any writing on the file system.
nas_fs -size [file system name] output is following.
[nasadmin@VNX5700-CS0 ~]$ nas_fs -size 1TB
total = 1032576 avail = 1032575 used = 1 ( 0% ) (sizes in MB) ( blockcount = 2147483648 )
volume: total = 1048576 (sizes in MB) ( blockcount = 2147483648 ) avail = 1032575 used = 16001 ( 2% )
Does Unisphere display volume's used capacity?
Roger_Wu
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October 24th, 2013 19:00
It might be the Metadata Overhead of the Pool. Refer to the whitepaper: http://www.emc.com/collateral/hardware/white-papers/h8222-vnx-virtual-provisioning-wp.pdf on page 17:
It is an approximate value, but 15.6 GB is quite close.
dynamox
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October 24th, 2013 20:00
but that's a file system, not a LUN.
Peter_EMC
674 Posts
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October 24th, 2013 23:00
It is the filesystem metadata overhead, which is about 1-2% of the volume. The metadata overhead on the pool will not be seen in the nas_fs -size output
kanta.mitsunari
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October 25th, 2013 00:00
Thank you for your support.
Do you have any documents about this?
Rainer_EMC
4 Operator
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October 25th, 2013 00:00
Yes - superblock, block maps and inodes - which are pre-created
Rainer_EMC
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October 25th, 2013 02:00
Not specially for VNX
Any good book about Unix file systems will teach you the principles