I've been doing a lot of reading and diking around and have even more questions!

 

I found this thread for the different but, not too dissimilar freeNAS; https://forums.freenas.org/index.php?threads/confused-about-that-lsi-card-join-the-crowd.11901/

is JBOD okay for the unRAID? I know single stripe/R0s is bad as it adds a layer of abstraction from the unRIAD to the drives. I know the M1015 is also highly recommended here at the unRAID community too! Does it need to be cross flashed to different firmware like the recommend in the above freeNAS link?

 

Parity, drives, drive number limits, unRAID v 6.2!

So in v6.2 the drive/device limit is 30 not including boot. If i read correctly those extra 4-6 drives can be used for VM pass through and other stuff like that but, not for the actual array. Is this correct? Could those extra drives be used as hot/read spares? IF yes is it or can it be practical?

 

If i have a few 2-4TB drives and add say a 10TB IronWolf as a parity all is well and good. I can even have a second parity drive however upon reading i'm confused on the verbage from the FAQ! If I understand the second parity must be the same size or larger than the first 10TB parity drive.

 

However array drive sizes come in to play, say i decide to up my game and I decide to stop with the panzy fru fru 3TBs and start adding 6,8 and 10TB drives!!! I'm not sure if that would work with out having a 80TB drive as the second parity? Or does that not matter since the parity is the sum of the 1s and 0s blah blah abstraction magic math stuff?(reading that one hurts my brain but, i get the concept) Could i have a single 10TB parity and start adding more large drives to array would need a second 10TB parity drive and or would that be highly advised? I'm seriously considering dropping in a new 10TB IronWolf once a month and or another 6TB+ drive.

 

 

EDIT: this video is helpful on array drive vs Parity drive sizes;

 

Also in an array with parity drive, does it also not keep a small amount of parity on each of the array drives?

 

 

EDIT: So far i'm looking at v6.2.4, idk if the newer version have anything, i think said they are bug fix versions.

Hi, welcome!

 

is JBOD okay for the unRAID?

Yes, unRAID requires JBOD.  The M1015 flashed to IT mode is very commonly used for unRAID.  unRAID isn't RAID, by the way, and doesn't use striping.

 

Parity, drives, drive number limits, unRAID v 6.2!

So in v6.2 the drive/device limit is 30 not including boot. If i read correctly those extra 4-6 drives can be used for VM pass through and other stuff like that but, not for the actual array. Is this correct? Could those extra drives be used as hot/read spares? IF yes is it or can it be practical?

The unRAID storage array can have 30 devices with a Pro license.  That's 28 data drives and 2 parity drives.  You don't want to store VMs on the unRAID storage array, it's too slow. They are more appropriately located on the cache pool (another 24 devices) or unassigned SSDs.  unRAID doesn't support hot spares.

 

If i have a few 2-4TB drives and add say a 10TB IronWolf as a parity all is well and good. I can even have a second parity drive however upon reading i'm confused on the verbage from the FAQ! If I understand the second parity must be the same size or larger than the first 10TB parity drive.

Yep, that's good.  The rule on parity drives is that you can have zero, one or two of them, and each one needs to be as large as, or larger than the largest data drive.  The parity drives can be different size but are commonly the same.

 

However array drive sizes come in to play, say i decide to up my game and I decide to stop with the panzy fru fru 3TBs and start adding 6,8 and 10TB drives!!! I'm not sure if that would work with out having a 80TB drive as the second parity? Or does that not matter since the parity is the sum of the 1s and 0s blah blah abstraction magic math stuff?(reading that one hurts my brain but, i get the concept) Could i have a single 10TB parity and start adding more large drives to array would need a second 10TB parity drive and or would that be highly advised? I'm seriously considering dropping in a new 10TB IronWolf once a month and or another 6TB+ drive.

Go ahead and re-read this:

 

http://lime-technology.com/wiki/index.php/UnRAID_6/Overview#Parity-Protected_Array

 

Parity is a calculation of the 1's and 0's, as you suspected.  You can start with a single parity drive.  You can add data drives at any time.  The reason to add a second parity drive is that it will protect your array from two simultaneous drive failures.  When you start getting 8, 12, or 16+ drives in an array there is a real risk that you could have more than one drive fail at the same time.  All too often we've seen people have one drive fail, and then a second one fail while rebuilding the first.  Dual parity solves for that.

 

Also in an array with parity drive, does it also not keep a small amount of parity on each of the array drives?

No, unRAID isn't RAID.  It doesn't stripe data or parity.

 

EDIT: So far i'm looking at v6.2.4, idk if the newer version have anything, i think said they are bug fix versions.

6.2.4 is the latest stable release.

 

Good luck!

so if you have no parity drive and 1 drive dies then there is no way to recoup or rebuild that data if the data isn't stored on parity drive OR it does indeed back up that data some where.

 

Is flashing the The M1015 to IT mode the only way to get it to support JBOD? That article said there is a difference between the device being an HBA and doing JBOD.

so if you have no parity drive and 1 drive dies then there is no way to recoup or rebuild that data if the data isn't stored on parity drive OR it does indeed back up that data some where.

Nope.  Without a parity disk installed, you're pooched if a disk dies.

so if you have no parity drive and 1 drive dies then there is no way to recoup or rebuild that data if the data isn't stored on parity drive OR it does indeed back up that data some where.

Nope.  Without a parity disk installed, you're pooched if a disk dies.

And even with a parity disk, the data is not really "backed up somewhere". It just allows a disks data to be calculated from parity plus all the other disks. Parity is no substitute for backups. Did you read the link given earlier about parity? It isn't magic and it isn't really even very complicated. I think understanding parity makes everything else about how unRAID operates make a lot more sense.

Is flashing the The M1015 to IT mode the only way to get it to support JBOD? That article said there is a difference between the device being an HBA and doing JBOD.

If you're going to use the M1015 with unRAID, you will need to flash it to IT mode just like FreeNAS.  The reference in that article about JBOD that's a little confusing refers to leaving the M1015 configured as a RAID card and passing through an unconfigured drive to the OS as JBOD.  You don't want to try that - stick with cross flashing the drive to IT mode.

The problem with large unRAID arrays is you can't just go out buy a 100TB usb hard drive to back it up to. i was gonna use unRAID as file store and a place to back my esxi virtual machines off my main server's raid 5. Few raid/file store solutions allow mixed drivers and expansion after creation.

The problem with large unRAID arrays is you can't just go out buy a 100TB usb hard drive to back it up to. i was gonna use unRAID as file store and a place to back my esxi virtual machines off my main server's raid 5. Few raid/file store solutions allow mixed drivers and expansion after creation.

You just have to decide what is worth backing up and how. My backup server has a lot less capacity than my main server, and I only use it to backup the unimportant stuff. My really important stuff will fit on 2TB and it has 2 offsite backups.

The problem with large unRAID arrays is you can't just go out buy a 100TB usb hard drive to back it up to.

That's when it's time to build a second unraid box. 

Which is why my 100+TB unRAID array is used for backups, it has become the second copy for my media files and other backups.