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Calculating Expected Space for Backups with Hard Linking

Question asked by wendy on May 30, 2018

Hello everyone.

 

We are preparing to move our FileMaker Server (currently 15) from a Mac to a Windows virtual/remote server set up by and managed by our IT department.

 

I am trying to calculated the total space needed for the Windows and Server software, live files, AND our backups, and am confused by the hard linking.

 

Our database is about 3.5 GB (and growing). We have 2 TB on the Mac available but haven't been given nearly that much on the Windows server so far. We do backups every half hour on our mission-critical database, and keep numerous historical backups, so it adds up.

 

As far as I can tell, the new Windows server does support hard linking. (I typed:   fsutil hardlink list <the full path and name of the file to  check> ...and got back a list, which I believe indicates FMS IS making hard links. Thx to the white paper by S Blackwell and W Decorte).

 

Cmd-I (Mac) or Properties (Windows) on a backup folder always shows the full 3.5 GB size for each backup, but my understanding is that each backup may not actually be that large, since we have 20 files and some of them are not changed frequently. Others change moment-to-moment. I'm hoping there is a way to find out how much REAL disk space each backup is actually taking, so I can do an over-time analysis and determine what we're likely to use in the future.

 

Do I understand all this correctly, and if so, is there a way to find out what size each of our backups is actually taking? Also, how much of a safety margin should be reserved for OS/FMS? (e.g. % of disk space?)

 

Thank you!

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