2013-07-04 11:37 PM
I'm trying to do a sub-file clone using the toolkit. Start-NaClone has a [-BlockRanges <BlockRange>] parameter.
Each block range is an instance of type DataONTAP.Types.Clone.BlockRange, but I can't work out how to populate a BlockRange object, and can't find any examples or documentation around this.
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4 REPLIES 4
Re: How do I provide BlockRanges to Start-NaClone
2013-07-04 11:41 PM
Check out the help for this cmdlet.
Get-Help Start-NaClone -Examples
PS C:\Windows\system32> Get-Help Start-NaClone -Examples
Starts a file/LUN or sub-file/sub-LUN clone operation.
-------------- Example 1 --------------
C:\PS>Start-NaClone /vol/vol2/lun1 /vol/vol2/lun1clone
Create a clone 'lun1clone' of LUN 'lun1'.
SourceFile : /vol/vol2/lun1
DestinationFile : /vol/vol2/lun1clone
CloneState : running
TotalBytes : 21476192256
PercentDone : 0
BytesCopied : 0
CloneType : lun
CloneId : 12
-------------- Example 2 --------------
C:\PS>Get-NaLun /vol/vol2/lun1 | Start-NaClone
Clone LUN 'lun1' and accept the default destination name 'lun1Clone'.
2013-07-08 10:00 AM
The BlockRange object is a block range descriptor containing three key fields: SourceBlockNumber, DestinationBlockNumber, and BlockCount. For LUNs, these block ranges are 512-byte LBA ranges, and for WAFL files they are 4k blocks.
You can create a BlockRange object using the New-Object cmdlet, for example:
$blockRange = New-Object DataONTAP.Types.Clone.BlockRange
$blockRange.SourceBlockNumber = 0
$blockRange.DestinationBlockNumber = 1024
$blockRange.BlockCount = 4096
Calculating the block ranges is the tricky part. For WAFL files it is fairly straightforward as long as you remember there are 4096 bytes in a WAFL block. If you are trying to sub-file clone a file on a LUN, it is significantly more complicated (and risky). You must find the block ranges the file occupies on the LUN, then calculate which block ranges fall in the part of the file you want to clone. Copy-NaHostFile handles this for you, but does not do sub-file cloning. Getting the source and destination block numbers wrong could very easily corrupt the LUN.