[solved] About to remove drives and rebuild parity, can I reorder disk#


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I'm in the process of removing a bunch of these 5400 rpm drives that are just crippling my file transfer speed. I've been buying up these 4TB WD Red Pro drives which during preclears have managed a nice 140 MB/s on average.

 

My current process for the last two drives I removed was to remove them individually, rebuilding parity every time (takes 14 hours or so). I have another three drives that I'm looking to remove.

 

I currently have rsync moving all data from those drives onto the new 4TB's as we speak

[*]Since I'm basically blanking out 3 drives, can I just remove them all at once and have one parity rebuild?

[*]As well, since i'm almost 5 drives short of what I used to have i have disk1, disk2, disk4, disk6, disk8, disk9. Can I change the order so that I don't have blanks inbetween? It really doesn't matter, just an annoyance whenever I look at the listing.

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You didn't specifically mention it, but I assume you have been using New Config to remove drives?

 

Yes, you can remove multiple drives, reorder your drives, or even add drives with or without data on them with New Config. When you start, unRAID will just build parity with all of the drives you have assigned, even if they are unformatted.

 

As I'm sure you know since you have already been doing this, be sure you don't assign a data drive to the parity slot!

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As noted above, you can do any reordering you want and/or eliminate as many drives from your config as you want anytime you do a New Config.  The ONLY thing you need to be certain of is that you assign the correct drive as parity.    [it sounds like you've got that well in hand -- but if you are ever uncertain, just assign ALL drives as data ... see which one shows as unformatted;  then do another New Config and assign that one as parity]

 

 

HOWEVER ... one other comment, r.e. your initial statement:

... I'm in the process of removing a bunch of these 5400 rpm drives that are just crippling my file transfer speed.

 

It's VERY unlikely that your 5400rpm drives were "... crippling my file transfer speed."    It's far more likely that the issue was older drives with low areal density.    Your new drives all have 1TB/platter areal densities ... so there's FAR more data/rotation to transfer => and thus the much better transfer speeds.

 

Nevertheless, the Red Pro's are superb drives ... and are indeed faster than the standard WD Reds, since they rotate at 7200rpm.    But the main improvement you're getting is definitely because of higher areal density -- NOT because of higher rotation speeds.

 

 

 

 

 

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[it sounds like you've got that well in hand -- but if you are ever uncertain, just assign ALL drives as data ... see which one shows as unformatted;  then do another New Config and assign that one as parity]

 

 

HOWEVER ... one other comment, r.e. your initial statement:

... I'm in the process of removing a bunch of these 5400 rpm drives that are just crippling my file transfer speed.

 

It's VERY unlikely that your 5400rpm drives were "... crippling my file transfer speed."    It's far more likely that the issue was older drives with low areal density.    Your new drives all have 1TB/platter areal densities ... so there's FAR more data/rotation to transfer => and thus the much better transfer speeds.

 

Nevertheless, the Red Pro's are superb drives ... and are indeed faster than the standard WD Reds, since they rotate at 7200rpm.    But the main improvement you're getting is definitely because of higher areal density -- NOT because of higher rotation speeds.

 

Interesting, never thought about platter density before. Makes sense.

 

I originally decided on the Red Pros for the 5yr warranty, higher rpm's just came along.

 

The current 1 and 2 TB's that I am removing are all WD Greens, at best they are 40-60 MB/s during a preclear.

 

I noticed when I added the 4TB as parity and copied something to a share that was specifically told to write to disk3 (another red pro) my array write speed was closer to 30/40 MB/s. As I watched the GUI I could see only the two red pro drives were being written to. That's what originally made me think the 5400's were killing the write speed.

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You'd see the same 30-40MB/s write speed with WD Reds ... it's the areal density that's making the speed difference.  The biggest gain you'll see with the Red Pros is that you'll get faster parity checks if ALL of your drives are Red Pros [ANY slower drive slows down the check to the speed of that drive].

 

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