Anybody know how big a volume I can create with Radiator 4.2.31?

[Grunchy]

I've got these Western Digital 6TB gold drives (please see attached file).

Here's the thing. If I let the ReadyNas 2100 create an X-Raid2 volume it uses up all of the space, and then it says the freshly created volume is 100% full, I can't do anything with it. No error state, just inaccessible.

So I switched to Flex-Raid so I can make individual volumes.

Again, if I let it make a volume this big (16631066 MB, and it takes 24 hrs to do it), it comes back with the volume being 100% full, can't do anything with it. No error state - it just says 100% full. It's in error.

So I deleted that and created Raid 0 volume using all 5718556 MB of channel 1. It works! There's a drive c, I can put a share on it and save files and everything.

So I made another Raid 0 volume using all 5718556 MB of channel 2, drive d. Works great.

So my question, and I know people have said all over the place that the maximum size is 16TB, but TB doesn't mean anything to Raidiator.

What I need to know is how many MB I can use to make a Raid 5 volume, what is the biggest size.

I want to know "what number can I type into the box" and if you look you'll see it doesn't say TB, it's asking how many MB to make.

It is going to take 24 hrs to create this volume, I can tell you that. If I get it wrong not only do all the disks crank away for 24 hrs straight, but then I get to delete the volume and start all over again with another number.

*PLEASE* do not reply to this request with "Gee I don't know" that's of no use to me.

I just want a response from the one person who knows, what number can I type in there that's as big as possible and is going to work.

No guesses: I want the real number.

And I already know some of you guys think 16TB means 16,000,000 MB and some of you think it means 16,777,216 MB and some of you think no it's 16TB including the overhead which is roughly 1/3 of the desired volume size so that should be 12,000,000 MB or so.

Lots of people think lots of different things. I only want to know, what's the real number that's going to work.

[Grunchy · Accepted solution]

Thanks everybody for your advice.

The final number: 16,273,912 MB is what you would put in. That's including "10 GB" for snapshots, although I think the software is in error, I think that really means "10 %" for snapshots.

(If you put 16,273,913 MB that is the smallest size that is too big to be created into a successful volume.)

For ReadyNas 2100 v1 running Raidiator 4.2.31.

[mdgm]

Do you have the 2100 V1 or the 2100 V2?

16TB is the expansion limitation. If you create a volume with equal capacity disks in place you should be able to create a larger volume. You just can't expand an existing 12TB volume past 16TB to say 18TB.

[StephenB]

4x6 TB disks would result in an 18 TB (16.4 TiB) volume.  As @mdgm says, that ought to work in a 4.2.x ReadyNAS - though you wouldn't be able to expand it.  What firmware are you running?  

The 2100v1 has a 32 bit architecture, so it might be more limited than the v2.

FWIW, building the RAID array takes the same amount of time for an empty volume as it takes for a full one.  RAID works at the raw block level (creating a virtual disk), and the parity blocks need to be built for every data stripe (even when the disk is empty).

[Grunchy]

Hi guys it's ReadyNas 2100 v1 running Raidiator 4.2.31.

Attached, see what it does if I say 12000000 MB.

[Grunchy]

This is what I get if I say 16631066 MB: it says disk is 100% full with 24 hrs to rebuild.

Also once that 24 hrs goes by, it stays at 100% full.

I know, "it should work" but it doesn't work.

[Sandshark]

Raidiator 4.2.x uses mdadm and LVM for creation of volumes.  Everything I have found says LVM is limited to "16TB" on a 32-bit Linux installation.  Now, since that's based on the bus width, I assume they actually mean 16TiB, which you are under.  But perhaps there is something in the Netgear Frontview portion that causes the issue.

When you say "I can't do anything with it. No error state, just inaccessible", does that mean you tried to actually put files into that "full" volume and it failed (after completion of sync)?

Do you have SSH enabled?  If so, what do you get from the following commands? 

cat  /proc/mdstat

lvdisplay

pvdisplay

vgdisplay 

The best way to put the results into a message is to use the insert code </> icon at the top of the editor.

[Grunchy · Accepted solution]

Thanks everybody for your advice.

The final number: 16,273,912 MB is what you would put in. That's including "10 GB" for snapshots, although I think the software is in error, I think that really means "10 %" for snapshots.

(If you put 16,273,913 MB that is the smallest size that is too big to be created into a successful volume.)

For ReadyNas 2100 v1 running Raidiator 4.2.31.

[mdgm]

It's also worth noting that you can have multiple volumes and I think from memory any disk can be in up to two of those volumes.

[Sandshark]

It would still be interresting to see the results of those commands to see what's causing that limit.  My only 4.2.31 system is a Pro2 with two 1TB drives, which I use as a "sandbox", so not remotely comparable to what you've created, but vgdisplay returns the following:

Pro2D:~# vgdisplay
  --- Volume group ---
  VG Name               c
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               927.00 GB
  PE Size               64.00 MB
  Total PE              14832
  Alloc PE / Size       14672 / 917.00 GB
  Free  PE / Size       160 / 10.00 GB
  VG UUID               RqY3q9-Wtgu-WP2I-znww-LNJZ-lXDM-7mNL8n

And I've assumed that the 10.00GB Free PE is the snapshot reservation.  To make a 16TB volume, the PE size is going to have to be bigger than 64MB, so that may be a part of the equation.  I suspect that's also tied to the reason for the expansion limits.  XRAID has to choose an appropriate PE size when you create a volume, and that can't be changed.  So it chooses one that works well for the current size and gives some expansion capability.

[StephenB]

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@Sandshark wrote:

It would still be interresting to see the results of those commands to see what's causing that limit. 

One reason for the inability to expand over 16 TiB is the inode size.  The system uses 32 bit inodes if the initial volume is < 16 TiB, and that can't be safely changed later (at least in the ext software in the 4.2.x ReadyNAS).  You need 64 bit inodes if the volume is > 16 TiB. 

But in this case (4x6TB drives), the system should have chosen 64 bit inodes.  

[Grunchy]

@Sandshark  here is that information:

readynas-15tb:~# cat /proc/mdstat
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md3 : active raid0 sda4[0] sdd4[3] sdc4[2] sdb4[1]
      502714368 blocks super 1.2 64k chunks

md2 : active raid5 sda3[0] sdd3[4] sdc3[2] sdb3[1]
      17190361536 blocks super 1.2 level 5, 64k chunk, algorithm 2 [4/4] [UUUU]

md1 : active raid6 sda2[0] sdd2[3] sdc2[2] sdb2[1]
      1048448 blocks super 1.2 level 6, 64k chunk, algorithm 2 [4/4] [UUUU]

md0 : active raid1 sda1[0] sdd1[3] sdc1[2] sdb1[1]
      4193268 blocks super 1.2 [4/4] [UUUU]

unused devices: <none>
readynas-15tb:~# lvdisplay
  --- Logical volume ---
  LV Name                /dev/d/d
  VG Name                d
  LV UUID                KUQjzC-A1oE-o84i-Ciy0-UBnx-L5qM-bgy2WS
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                479.38 GB
  Current LE             7670
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/c/c
  VG Name                c
  LV UUID                mSfnz6-jwms-kAFF-ugwV-OqXS-6M5s-MRbrNG
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                16.00 TB
  Current LE             262143
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:1
readynas-15tb:~# pvdisplay
  --- Physical volume ---
  PV Name               /dev/md3
  VG Name               d
  PV Size               479.38 GB / not usable 0
  Allocatable           yes (but full)
  PE Size (KByte)       65536
  Total PE              7670
  Free PE               0
  Allocated PE          7670
  PV UUID               Lpje0M-6qSC-rf6P-UGOu-0LeP-giXI-lqxurA

  --- Physical volume ---
  PV Name               /dev/md2
  VG Name               c
  PV Size               16.01 TB / not usable 0
  Allocatable           yes
  PE Size (KByte)       65536
  Total PE              262303
  Free PE               160
  Allocated PE          262143
  PV UUID               7qS6C9-n3iJ-GI3J-2AcE-1dLd-xfTH-Qi0S0K

readynas-15tb:~# vgdisplay
  --- Volume group ---
  VG Name               d
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               479.38 GB
  PE Size               64.00 MB
  Total PE              7670
  Alloc PE / Size       7670 / 479.38 GB
  Free  PE / Size       0 / 0
  VG UUID               THs0Mn-NV28-0cZI-iJ3R-wMRI-9ZWl-RmzS00

  --- Volume group ---
  VG Name               c
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               16.01 TB
  PE Size               64.00 MB
  Total PE              262303
  Alloc PE / Size       262143 / 16.00 TB
  Free  PE / Size       160 / 10.00 GB
  VG UUID               tK4AtE-uzFv-xv6z-IJj3-xeM9-9ZQt-3lpLca

[Sandshark]

Interesting.

  --- Volume group ---
  VG Name               c
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               16.01 TB
  PE Size               64.00 MB
  Total PE              262303
  Alloc PE / Size       262143 / 16.00 TB
  Free  PE / Size       160 / 10.00 GB
  VG UUID               tK4AtE-uzFv-xv6z-IJj3-xeM9-9ZQt-3lpLca

I haven't quite figured out how they got that number, but it's good info for anyone with an NVX, 1500, or 2100V1.

[StephenB]

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@Sandshark wrote:

For some reason, @Grunchy could not respond in the forum, but he provided the following in an IM

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The automatic spam filter kicked in. I released the more recent post.

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@Sandshark wrote:

  VG Size               16.01 TB
  Alloc PE / Size       262143 / 16.00 TB

I haven't quite figured out how they got that number, but it's good info for anyone with an NVX, 1500, or 2100V1.

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So a 16 TiB ceiling on the 32 bit 4.2.x NAS.

@Grunchy:  One option is to switch to flexraid with only three of your disks in place, and set that up as RAID-5 (volume c).  Then hot-insert the last disk and set it up as RAID-0 (volume d).  You'd get 12 TB in the c volume, and 6 TB in the d volume.  You wouldn't have RAID redundancy on the d volume.