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ZFS Drive Size and Cost Comparison Spreadsheet

Western Digital Drives - The Preferred Drives of FreeNAS and TrueNAS CORE
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diedrichg

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This is the discussion thread for this Resource. To find the actual Resource, please use the Overview tab above to navigate to it.

The original post follows below, in the spoiler tags:
Hi all. I have created a shared spreadsheet to supplement @Bidule0hm 's ZFS RAID Size Calculator. The purpose of the spreadsheet is to compare 1:1 the potential size of your pool if you are planning RAIDZ1 or RAIDZ2 (for example). You can then edit the top portion of the spreadsheet to figure the most cost-effective ($/TiB) option for your build.

I used Bidule0hm's ZFS Calculator to calculate the usable TiB for X-sized drive and Y-number of drives to be used. Feel free to edit the top portion of the spreadsheet to your needs. Let me know if something in the protected cells needs to be changed or added.

Usage:
  1. Enter: Z1, Z2 or Z3 redundancy level (A16), 4 (TB) drive size (B16), # drives (C16) and $/drive (H16)
  2. Enter: Z1, Z2 or Z3 redundancy level (A17), 6 (TB) drive size (B17), # drives (C17) and $/drive (H17)
  3. Compare Price/usable TiB
  4. Compare Total Cost
Main calculations and comparison table


Example 1: Look at Lines 16 and 17 above. You are comparing building a system with (8) 3TB drives vs (6) 4TB drives. You can see that you will spend $5 less for the (6) 4TB drives but lose 11% (1.4TiB) in usable storage! It's a scenario like this where the spreadsheet allowed you to make an informed decision to go with (8) 3TB drives to maximize storage for the same total cost out of pocket.



Example 2: In this scenario in comparing lines 16 and 17 you are comparing building a system with (8) 3TB drives vs (5) 8TB drives. You can see that you will spend 76% ($670) more for the 8TB drives but for a gain of 33% (4.3TiB) in usable storage. *This is why I left the drive size column editable - it allows the user to compare any size drive to each other that otherwise would require some manual math if the drive size column was static.

Drive size calculations per RAIDZ level (RAIDZ1, 2 and 3, Mirror and Stripe are available for your research )
 
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Bidule0hm

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Great idea and good spreadsheet ;)

But there's two things:
- please use the link to the thread instead of the link to the app (because the app's URL changes every time I make an update to the app)
- you might want to use $/TB instead of $/GB because the prices are very low and even the 1/10 of cents aren't precise enough I think (a few lines have the same value because of the rounding)

NB: I just want to re-warn that there's a bit more overhead (a few %) than the app currently process so the real life usable space will be a bit lower than what's calculated.
 

diedrichg

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- please use the link to the thread instead of the link to the app (because the app's URL changes every time I make an update to the app)
- you might want to use $/TB instead of $/GB because the prices are very low and even the 1/10 of cents aren't precise enough I think (a few lines have the same value because of the rounding)
Done and done. Thank you!
 

Bidule0hm

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You're welcome ;)

I've done a thing I wanted to do for a long time: static link for the app --> http://biduleohm.free.fr/zfsraidsarc/ so now if you need to link it, bookmark it, whatever it, you can use this link; but it's still better to use the thread link because the app's manual isn't integrated to the app (just one more thing on the todo list I guess...) :)

Edit: the prices are wrong because you've put 100 but 1 TB = 1000 GB. And you can now round them to cents, no need to have the 1/10 of cents.
 
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Ericloewe

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Very nice addition.
 

diedrichg

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Update:
"ZFS Drive Size and Cost Comparison Spreadsheet" updated to support the new 8TB NAS and 10TB Enterprise drives!!
 
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tealcomp

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Hi Fellow Members:

This is my first official post after trying to perform my due research diligence on the subject of building a FreeNAS server. I ran across this most excellent spreadsheet for calculating space and was wondering if it could perhaps be added to the resource section of the forum? It is in fact the first place I went to look for this document (I had run across this spreadsheet earlier in my research). I look forward to presenting my first build for consideration (in the proper section of course), in the very near future.

Regards,
-Dan
 

diedrichg

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Update:
"ZFS Drive Size and Cost Comparison Spreadsheet"
  • Kudos to the person who made the hlookup to simplify the user interaction with the spreadsheet. There were some issues with the hlookup that I was able to solve! This means the spreadsheet is 100% accurate and complete. Please notify me if you notice something is missing or wrong.
  • Added some pretty images to this post so a person can get an idea of what they will see within the spreadsheet.
  • Added two Examples below the first image in this post to show the importance of doing some research before diving in and buying parts that would cost you storage space or money.
  • Added % Cost Increase columns and separated out the storage space calculations from the cost calculations
 
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wblock

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Wasn't there a RAIDZ2 4TB, 4 drives row yesterday?
 

diedrichg

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It's there. You can change the RAIDZx level, drive size and number of drives. Those cells are not static.

The issue with the "hlookup" automation was that the drive size cells had to be a numerical value. Google Sheets wasn't handling plain text (8TB, 10TB) lookup properly as Excel would. Consequently, I had to make the "Drive Size in TB" cells numerical (8, 10) to make the hlookup function properly.

 
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Seems that GB sizes are not supported in calculator. I'm unable to evaluate costs for an SSD configuration, where sizes are 256, 400 and 480GB.
Probably, moving from TB to GB by using "2000" as usable size instead of "2" would be a solution.
 

Ericloewe

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Seems that GB sizes are not supported in calculator. I'm unable to evaluate costs for an SSD configuration, where sizes are 256, 400 and 480GB.
Probably, moving from TB to GB by using "2000" as usable size instead of "2" would be a solution.
Those figures are powers of ten, too. Yes, even SSDs.
 

diedrichg

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Seems that GB sizes are not supported in calculator. I'm unable to evaluate costs for an SSD configuration, where sizes are 256, 400 and 480GB.
Probably, moving from TB to GB by using "2000" as usable size instead of "2" would be a solution.
You are correct. I currently have the calculations portion looking for hard drive sizes, not SSDs. It's not impossible to add the SSD values but will require some modification to the SSD tables. The issue is the "hlookup" formula expecting numerical column headers as it can not handle certain headers such as "480GB".

I will create a secondary calculations section at the bottom of the calculator specifically for SSDs.
 

diedrichg

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Seems that GB sizes are not supported in calculator. I'm unable to evaluate costs for an SSD configuration, where sizes are 256, 400 and 480GB.
Probably, moving from TB to GB by using "2000" as usable size instead of "2" would be a solution.
01/10/2017
  • Added a brand new table for SSDs! You can find it at the bottom of the spreadsheet. SSD size had to be in thousands of GB for the "hlookup" to work.
  • Set the SSD size/price comparison calculations with some starter numbers... including some prices that I quickly looked up on Newegg. Of course, modify the Edit regions to your personal needs.
  • Added 400GB and 480GB SSD sizes to all three RAIDZ tables.
 
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diedrichg

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Last change for a bit. I believe this completes the spreadsheet to the level I'd like to see it.

01/11/2017

  • Changed to Usable TiB (HDD) / GiB (SSD) to represent what drive space you would see in the FreeNAS GUI once drives are installed and configured.
 
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Ericloewe

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Have you had a look at the resources section? This would be a great fit and would make it easier to manage.

You can even host the file on the forums, which is generally a tidier solution.
 

diedrichg

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Update: Added a link to download an offline xlsx version for your own personal use.
 
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@diedrichg Question: in cell E105, why do you say that for 2-way mirrored 4TB drives, you get 2.86TB of usable space? Shouldn't that be 3.86TB? That, or something pretty close to that, is the number that I remember FreeNAS 11's GUI told me I had when I configured my 1 set of 2-way mirrored 4TB pool (i.e. 8TB/2 - swap space).
 
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