DIY X-RAID2/Hybrid RIAD: scenarios?

[Gralgrathor]

I'm new in the NAS/DIY community, and have just received notice that my old fileserver, a Linux machine hosting Just a Bunch of Disks, is obsolete. I want to replace the old clunker with a solution that is reasonably inexpensive in both hardware acquisition and running costs - low power usage, low noise, and so on. Since I have a collection of rather new WD disks, all of different size, that I would like to reuse initially - but gradually replace with larger disks as it becomes necessary and as they become available and affordable - I'm looking for a way to implement something like Netgear's X-RAID2 or Synology's Hybrid RAID on a DIY NAS. What I would like to hear is whether anyone has experience with something like this, or knows whether such a thing is feasible at all, for a random newbie like me.

An example of a scenario I thought up after reading a thing or two* about RAID and ZFS:

1) Would it be possible to split the disks available into partitions of 250 and 500G, implement a ZFS filesystem over these partitions, in such a way that no two partitions in any vdev are on the same physical disk, and vdevs spanning three disks or more use RAID5, while vdevs with 2 disks use RAID1?

2) If (1), then what kind of CPU performance would such a setup require to get any kind of bitrate out of the machine? Might an ATOM D510 suffice? What kind of memory? Would 1G of DDR2 suffice?

3) If (1), then would it be possible to resize (ie. adding partitions to) existing vdevs without having to backup the data, delete them, rebuild them, and restore data?

4) If (1) and not (3), then would it be advisable to maintain a maximum vdev size, and keep at least one vdev (non-RAID) in reserve for the procedure described in (3)?

5) Given (1): Synology SHR systems more, and Netgear X-RAID2 systems a bit less, both offer sophisticated management software that perform most actions necessary to dynamically optimise diskspace usage automatically, and offer a reasonably simple user interface. Would it be feasible to get or build such a suite of management software? How might one go about this?

6) What questions have I forgotten?

And of course, if not (1), then

7) How else might one achieve the same flexibility as offered by X-RAID2 and Synology Hybrid RAID, while keeping costs and noise low?

Your questions, experiences, remarks and other contributions, would, again, be much appreciated.

Gr,

Gr.

*) And drinking a pint or two.

 

[Ken_z71]

try FreeNAS!

Check out FreeNAS if you want to build your own.

It works well with older hardware - the specs you cited would be fine.

The RAID config with various size disks could be done - check out this link

An added perk of FreeNAS - you can add extra apps like media streaming, bit torrent clients, FTP server, etc.

 

[Hydaral]

An example of a scenario I thought up after reading a thing or two* about RAID and ZFS:

1) Would it be possible to split the disks available into partitions of 250 and 500G, implement a ZFS filesystem over these partitions, in such a way that no two partitions in any vdev are on the same physical disk, and vdevs spanning three disks or more use RAID5, while vdevs with 2 disks use RAID1?

Yes, but this would be somewhat complicated to manage and you would lose ZFS's disk-level features, see this post for my recommendation for many differently sized disks on ZFS.

2) If (1), then what kind of CPU performance would such a setup require to get any kind of bitrate out of the machine? Might an ATOM D510 suffice? What kind of memory? Would 1G of DDR2 suffice?

I have NexentaStor running a ZFS mirror on two 500GB disks on an Atom D525, it barely exceeds 15% CPU, RAIDZ requires quite a bit more for calculating parity, but I wouldn't think it would be a problem. You will definitely need more RAM though, I have 2GB and it's using all of that.

3) If (1), then would it be possible to resize (ie. adding partitions to) existing vdevs without having to backup the data, delete them, rebuild them, and restore data?

Adding vdevs? Yes, easily. You add the new vdev to the pool and it automatically becomes available. Resizing existing vdevs? No, not yet. This is probably the most requested feature for ZFS. This is one of the management problems you will have if you use partitions in your vdevs.

7) How else might one achieve the same flexibility as offered by X-RAID2 and Synology Hybrid RAID, while keeping costs and noise low?

To paraphrase the project triangle (good, fast, cheap, choose two): flexible, easy to manage, cheap, choose two. As stated before, you can do it, it's just hard. What do you want to do when a disk fails, spend three hours working out how to allocate the space on the new disk and setting it up, all the time you are non-redundant and keeping in mind one incorrect command could wipe out your array? Or do you just want to plug in the disk and tell the NAS to rebuild?

Your questions, experiences, remarks and other contributions, would, again, be much appreciated.

You may have worked it out by now, but my recommendation is: diskspace is (reasonably) cheap, weigh that against the value of your data and how long it will take to restore everything if something goes wrong with your complex system. Use disk-level vdevs in ZFS.

 

[MadGabZ]

An example of a scenario I thought up after reading a thing or two* about RAID and ZFS:

1) Would it be possible to split the disks available into partitions of 250 and 500G, implement a ZFS filesystem over these partitions, in such a way that no two partitions in any vdev are on the same physical disk, and vdevs spanning three disks or more use RAID5, while vdevs with 2 disks use RAID1?

Read up on this guys attempt to do a poor-mans Drobo.... Its rather technical but does a damn good job of explaining what it takes!

 

[Generious]

Check out FreeNAS if you want to build your own.

It works well with older hardware - the specs you cited would be fine.

The RAID config with various size disks could be done - check out this link

An added perk of FreeNAS - you can add extra apps like media streaming, bit torrent clients, FTP server, etc.

Avoid the latest version of Freenas its horrible and slow and crappy read/write speeds.

 

[circuitnine]

Avoid the latest version of Freenas its horrible and slow and crappy read/write speeds.

Wish I would have known that before I pulled the trigger haha, I have a bad tendency of making impulse purchases with stuff like this. This is the one bad purchase i have made as far as my network is concerned because it was not able to work in tandem with the email marketing software and the people who had been staffed via IT jobs companies. I had to move forward and although it wasn't a major problem, but it was a pain.