Adding more disks


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Dumb question.  I have 2 10tb disks in my Array.  I'm going to be adding 2 more 10TB disks.  I don't have a parity drive, just a cache drive.  If I add these 2 to the system, will they automatically get added to the disk array because of the settings --> global share settings are set to all?  The desired outcome is now having a 40TB share to play with. 

Screenshot_6.jpg

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52 minutes ago, DanRegalia said:

If I add these 2 to the system, will they automatically get added to the disk array because of the settings --> global share settings are set to all?

I would word this a little differently.

 

If you assign disks to new data slots in the array, then those disks are automatically available for User Shares because of your Global Share Settings.

 

The settings of each specific User Share determines which disks are included for that specific User Share.

 

Why aren't you using parity?

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On 3/29/2021 at 5:26 PM, trurl said:

I would word this a little differently.

 

If you assign disks to new data slots in the array, then those disks are automatically available for User Shares because of your Global Share Settings.

 

The settings of each specific User Share determines which disks are included for that specific User Share.

 

Why aren't you using parity?

 

Thanks... I may not be that up to date on the lingo, I'm a software developer, not so much a server guy.  I thru them in just because I needed a quick server, with lots of space to host VMs in a dev environment.  Not sure if I can add parity to it now.  I'm thinking if I did do that, I'd lose 10TB to have a parity drive?  This is one of those things I should probably address and see what the difference ends up becoming. 

 

So, now the questions come up.... Do I add add the 2 new disks, make one parity, start moving information over to the new ones, then add the other ones to it, can I do that?  I am slowly moving information off of my drives on my computer as I prepare for a new system, and then will slowly add those to the server as well (3x 6TB drives)

 

If you were to make recommendations what would you do?

 

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  • 2 weeks later...

I am suggesting that parity is never a substitute for backups.

 

But parity is still a good idea.

 

Don't cache the initial data load. Never try to cache more than cache can hold. It is impossible to move from cache to array as fast as you can write to cache.

 

If you keep all the source data until after you get it all copied to your Unraid server, you could wait until then to add parity since the copy would go faster without parity.

 

Then, after making sure you have another copy of anything important and irreplaceable, you could reuse the disks with the source data in your new server.

 

You get to decide what qualifies as important and irreplaceable.

 

 

 

 

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So, technically, I'm at Raid 0.  You're suggesting moving into a Raid 5 scenario.  I can technically move everything onto my spare drives, and everything onto 1 10TB, then take the 3 empty 10TB drives and use 1 for parity, and 2 for storage.  That will put me back at 20.  Then, If I move the rest of it onto the 20tb RAID5 setup (not using cache) can I add that 10TB that was holding stuff into the array to give myself 30TB of Raid5, or do I have to break the array in unraid to get it added.

 

I see your original question, If I don't care about anything but storage, then leave it as is with 40 and just add them.  But if I do want to have the opportunity to save the data and rebuild the disks using parity, I should do that.  But having a good backup for stuff I care about is really the smartest Idea for data security... (I have a 10tb external I use for cold backup). 

 

So, back to the original question then, can I just flip new drives in it, and will UNRAID let me add them to the disk arrays.

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10 minutes ago, DanRegalia said:

So, technically, I'm at Raid 0.

As far as I know you're not at RAID anything. Why do you think you're at RAID 0? Your 2 data disks are independent and provide no redundancy.

 

And I'm not suggesting RAID anything.

 

Unraid IS NOT RAID. Even after you add parity you won't be at RAID anything, at least not technically. Unraid allows a parity disk that lets you rebuild a missing disk from parity and all the other disks, but the implementation is different from any traditional RAID.

 

Unlike RAID, Unraid allows you to mix different sized disks in the array, and you can easily add disks without rebuilding the array. Also, each data disk in the array is an independent filesystem that can be read all by itself without the other disks. This also means no striping, of course, so Unraid won't be as fast as striped RAID.

 

 

 

 

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Gotcha... so now I'm at a completely different level of confused, but work with me here, I'm still new to it.

If I wanted to use traditional raid, I can build it all using the raid controller on the motherboard (bios setup)... If I wanted to.  I really don't. 

 

So, with UNRAID not being a traditional disk management system, I could technically just add a new drive, designate it as a parity drive and let it keep moving on?

Or just flip the 2 drives into it, designate one as parity, and the other as storage, and not care all that much what is going on? 

All I have is a JBOD disk array, and technically this is not a problem.  As long as I have SMART turned on, will UNRAID notify me if I start getting too many disk errors, and move everything it can from that disk if space allows?  Is there a way to even do that with UNRAID? 

 

BTW, I really do appreciate you helping me work thru this.  Again, all my important stuff is sitting on my regular computer, is backed up to my one drive, etc.. and this is more of a dev/test server.  I mean, I don't want to have to rebuild it if something goes wrong, but I'm not all that tied to the data on it, other than a bitching movie collection.  I will be adding raw movie files and stuff to it later for processing which is why I want to add 20 more TB to it for storage.   

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As I recently added a (12tb) disk and was interested in this thread. My journey...

 

Before getting UnRAID, I had a 24tb RAID5 (4x6tb = 18tb usable, 1 parity).

 

I now I have an UnRAID with 3x12tb and 1x6tb. I "decided" to loose 12tb to parity and have 30tb usable. The "old" RAID5 I use for backup now.

 

I had a drive fail in the RAID5 and it rebuilt fine, but it wasn't pleasant. It takes a LONG time to transfer/save/rebuild data.

 

Backup is everything; parity is making it "easy." I say, "easy" because I spent weeks transferring data to UnRAID. Test how long it takes to transfer 30tb of data and consider your server being down for that length of time. Parity is worth it when it works; and backup is everything if parity fails.

 

Just my two cents worth.

 

6.

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7 minutes ago, 6of6 said:

As I recently added a (12tb) disk and was interested in this thread. My journey...

 

Before getting UnRAID, I had a 24tb RAID5 (4x6tb = 18tb usable, 1 parity).

 

I now I have an UnRAID with 3x12tb and 1x6tb. I "decided" to loose 12tb to parity and have 30tb usable. The "old" RAID5 I use for backup now.

 

I had a drive fail in the RAID5 and it rebuilt fine, but it wasn't pleasant. It takes a LONG time to transfer/save/rebuild data.

 

Backup is everything; parity is making it "easy." I say, "easy" because I spent weeks transferring data to UnRAID. Test how long it takes to transfer 30tb of data and consider your server being down for that length of time. Parity is worth it when it works; and backup is everything if parity fails.

 

Just my two cents worth.

 

6.

 

I really appreciate your input here.  It's helping me figure this out.  So, you have 30TB 12+12+12+6, and using one 12 for parity.  How does that work with the 6tb in the array for parity?  Is it really that fluid to where it doesn't matter with this JBOD?  Based on this, I could literally just throw in all 10TB drives for storage, and then 2 6TB for 'parity' drives, and everything may be okay... 

 

Backup is another problem I will be facing once I get into my storage a little bit more, and care more about what I have on there.. But for now, I mean, if I drop a disk, I can easily replace it, and let it rebuild, instead of trying to transfer, move, setup new VMs, etc.. Which is always a huge amount of time.  We're talking entire development environments that I'd have to rebuild.. timewise..

 

So, I guess, the question stands, can I just throw in a bunch of disks, tell them they are either parity or storage... and let Unraid figure the rest of it out for me?

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DR > How does that work with the 6tb in the array for parity?

 

Parity is different in UnRAID. Well... the same, but different. There are videos that can explain it better than I can, but if 0+0+1+0+1+0  = "even number"; it's zero, and it doesn't matter the file system, it's just binary math.

 

DR> ...doesn't matter with this JBOD?

 

I don't know what JBOD is, but for parity to work (in UnRAID), the parity drive must be the largest drive (so it has capacity to store the parity "0/1" bits in their proper place.

 

DR> ...and let Unraid figure the rest of it out for me?

 

Sadly, no... UnRAID will let you shoot yourself in the foot as quickly as any other OS.

 

As far as, "replacing disks"... That's never easy and if anyone ever says it is, their making a video with an empty disk for demonstration purposes. :)

 

6.

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6 hours ago, 6of6 said:

As far as, "replacing disks"... That's never easy and if anyone ever says it is, their making a video with an empty disk for demonstration purposes

As far as parity is concerned all disks are full to capacity with ones and zeros. 

 

Rebuild is easy it just takes 2-3 hours per TB

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