New Member: Advice on which RAID setup to proceed with new OMV server

Hello All,

I'm rather new to the home media/htpc/nas/server world. I only started getting into it at Christmas. Since Then I built a fanless Intel NUC with Windows 8.1 & XBMC as my HTPC appliance and used a 2bay QNAP NAS to hold my media. The NAS only holds media and a system image of my HTPC. My wifes iMac uses Time Machine to backup to an external WD hard drive and I currently do not have it connected to my NAS. I underestimated how quickly my media needs would fill up the 2 BAY and I'm at 60% of my 3TB WD RED.

I decided to do some futureproofing and purchased a Lenovo TS140 with the xeon processor. I'm going to install OMV on a spare SSD, and I have 3 new 3TB WD RED's to install, in addition to the existing 3TB red in my QNAP. I use XBMC now but I want to try out Plex and see if that suits the family better or not. I want off-site family to be able to play media off the server down the line as well which is why I went with the Xeon processor for transcoding.

Questions

1) Originally I was just going to go with Raid5, but than I noticed people using greyhole, snapraid, and a combination of Greyhole & Snapraid. Considering the data on the the server is going to be mostly media, with some important system images/family photo's, what do you suggest for the raid setup? I don't understand how combining greyhole and snapraid works.

2) Will there be any possibility of taking the existing drive out of my qnap and install it into my OMV server, and then pooling the other 3 drives without losing the data? If not that's OK, I understand RAID is not a backup and have been doing weekly syncs with a 4TB external drive, so I know I can transfer that way if need be.

Definetly almost all media. I've got maybe 20 GB for the system image. I've got 100GB from an old external drive which I used to store everything off an obsolete laptop. The rest is all media.

Do you suggest pooling the drives?

Why did you choose aufs?

How does pooling with aufs handle failures? If drive 3 fails out of my 4, will OMV tell me that drive 3 failed and then all I have to do is swap it out, restore from a backup?

Another question, if I have 4x3TB drives in my NAS. What form of non-cloud back do you guys prefer? External USB drives, or another enclosure with HDD's inside?

I understand aufs has no redundancy and that's what snapraid is for, so when a failure occurs raid will restore the new drive. I may have worded my question incorrectly.

Maybe I should have asked how you perform your backup first. Do you backup the entire pool, or the single disks from your pool?

If it's single disks, how to you keep track of what files were on a specific drive so that you can restore them from your backup?

Or do you backup the entire pool, and just sync the new pool with the new drive with your backup?

Zitat von ryecoaaron

I never work with an individual disk in my aufs pool. So, I would backup the entire pool. If you had to replace a drive, I would rsync the pool from the backup pool.

Makes sense! Thank you

Is it easy to expand the pool in aufs after data is written to the pool?

I want to get this system up in parallel with my existing NAS. Once I'm satisfied everything is working properly, I want to remove the hdd from my nas place it into the OMV box, format it, and add it to the pool.

You guys are very helpful. I'm excited to be a part of this community.

I haven't decided if I want to proceed with snapraid or not yet. Is it possible to create a pool with 3 x 3TB drives, copy data over, and if I want to add snap raid later on, I can add a 4th drive for parity and enable snapraid? Or must I start with snapraid from the beginning?

Perfect! Thanks!

Hello Again,

I'm getting pretty close to migrating to my OMV box now. The hardest part so far is understanding the shares. I don't fully comprehend them yet but everything is working well so far.

One issue I've encountered. I set up an AUFS pool, and I used RSync to move files from an external drive to my pool. Unfortunately, when I look in the file systems tab, the data has only seemed to be written to 1 hard drive out of the 3.

sda1 ext4 capacity: 2.69TiB available: 1.18TiB mounted: yes referenced: yes
sdb1 ext4 capacity: 2.69TiB available: 2.69TiB mounted: yes referenced: yes
sdc1 ext4 capacity: 2.69TiB available: 2.69TiB mounted: yes referenced: yes

/media/uuid/ aufs capacity: 8.06 TiB available: 6.55TiB mounted: yes referenced: no

Is there any other way I can check to make sure I created the pool correctly and that it is functioning as it should? I only created shares on the aufs pool, I setup nothing on any individual drives/branches.

Zitat von ryecoaaron

Your pool isn't referenced. You need to make a shared folder on the pool and read/write to that shared folder. Looks like you wrote to a shared folder for sda1. I wouldn't even create shared folders for the individual disks.

That's the thing, I only created my shares to the pool. I haven't create any shares to any individual drives.

When I get home, I will take some screenshots and post them up before executing that command. I'm concerned as to why my pool isn't referenced although my shares with data/files are on the pool.

This seems to be the same problem: http://bugtracker.openmediavault.org/view.php?id=1340