Best way to deal with these drives/data? Is raid the most logical "backup"?

[Chug]

I've been running a windows server for a few years now. This consisted of 5x 3TB WD Greens. I've built a FreeNAS system, and have 3x 6TB reds available to put in it. The problem is I've used one of those 6tbs for data, so I only have the FreeNAS server running right now with 2x 6tbs and 5.5gb of available data. Looking at the calculators, this seems to be normal, and that size doubles every time you put 2 drives in. I was unable to select any option other than "auto" when setting up the pool.

I appreciate raid isn't a backup and this allows drives to fail and the ability to replace them without loosing data, but maybe I'm missing an option or not understanding fully, because if you only get half the data, surely the most logical/safest option would be to just run the drives without raid, get full capacity from the drives, and use what would of been used in a raid to have a physical backup (in a bomb proof safe in need be) Technically you're wearing the drives using them, and aside from the first point I'm not sure if I'm seeing any other benefits?

I read about vdevs and zpools previously but can't find it now typically. Can someone confirm I understand/remember this correctly the best way to add drives to a zpool is in pairs via a new vdev?

So when I get the data off the windows 6tb onto the server, there isn't any point in adding the single 6tb on its own? As single drive vdevs arent recommended?

 

[wblock]

What you have now is a mirror. RAID of any type is nice because it helps avoid expensive downtime. In a mirror, if one drive fails, your computer still works. If there was only one drive, and it failed, that computer would be down. It takes time to swap in an external spare.

Then you have to deal with the data that was created in the time between the last backup and when the drive failed. That can be expensive to recreate.

So it depends on your usage. If you have static data that is easy to recreate, and downtime is not a big deal, and losses of the most recent work are not important, RAID might not be needed in that instance.

 

[Chug]

Fair enough, thanks for the reply. This application is your average film server, nothing fancy or imperative.

I'd want maximum capacity really, I don't mind giving up a drive for parity, but not one for eveyrone in use.

Whats the best way to set this up?

 

[GBillR]

I read about vdevs and zpools previously but can't find it now typically. Can someone confirm I understand/remember this correctly the best way to add drives to a zpool is in pairs via a new vdev?

So when I get the data off the windows 6tb onto the server, there isn't any point in adding the single 6tb on its own? As single drive vdevs arent recommended?

I think what you are looking for is here: https://forums.freenas.org/index.ph...ning-vdev-zpool-zil-and-l2arc-for-noobs.7775/

 

[Glorious1]

Fair enough, thanks for the reply. This application is your average film server, nothing fancy or imperative.

I'd want maximum capacity really, I don't mind giving up a drive for parity, but not one for eveyrone in use.

Whats the best way to set this up?

Given what you and wblock said, you probably want RaidZ1 with your three drives and a very reliable backup.

 

[Chug]

Original plan (before I read the guides) was to add drives as I copied the data over. Was also going to sell the 3TB green drives, and buy all 6TB. Prices of used 3TBs are not much so I decided to use them.

I've made one Vdev and zpool from the 5x 3TB drives, to give 10.5TB. Filled that up, free'd 2 6tb drives. Since been trimming the rest, and disassembling anything in the house with a hard drive to free up that last 6tb drive. Bought another 6tb drive, plan to setup another vdev of 4x 6tb drives and add that in one go. Unfortunately that does mean I am now 2 sata ports short of what I need.

Would it be wise to have each vdev on their own controller rather than split over various?

I've found a Dell Perc 6 UCP-61 kicking around, as well as an adaptec sas controller. From what I read these aren't recommended, problem is the M1015 doesn't seem to be freely available on ebay UK and has to come form Hong Kong.

 

[wblock]

Dell Perc H310 or H200 controllers are equivalents to the M1015 or the LSI 9211-8i. It can be a hassle to get the firmware changed, but is achievable.

 

[Chug]

Cheers, picked up an H310i, flashed it.

Trying to add the 4x6TB drives as another Vdev to the zpool, but it will only allow a mirror with 10.5TB available or a stripe at 22TB. I get the impression neither of these are what I need?

 

[GBillR]

Cheers, picked up an H310i, flashed it.

Trying to add the 4x6TB drives as another Vdev to the zpool, but it will only allow a mirror with 10.5TB available or a stripe at 22TB. I get the impression neither of these are what I need?

What you want to do is add 2 new mirrored vdevs (2x6TB each) to the existing pool. Not having done this yet, I can't give you the exact steps, but the docs indicate you need to perform this in 2 separate steps: http://doc.freenas.org/9.10/storage.html#extending-a-zfs-volume

EDIT: My mistake... I misread the thread and assumed you were trying to add a mirrored vdev.

I am pretty sure you should be able to do what you want with a 4 disk vdev. Are you sure you setup the zpool like you think you did? Or perhaps the GUI won't let you use a different type of vdev when expanding the pool?

 

[Glorious1]

Why shouldn't he be able to do a RaidZ1, as the original plan, or RaidZ2?

 

[GBillR]

Why shouldn't he be able to do a RaidZ1, as the original plan, or RaidZ2?

Yup... my misread.

He should be able to do that if he wants. Although raidZ1 might not be a good idea with 6TB drives...

 

[Chug]

I don't really want to give up that much disc space ideally. If I could have 1/4 for redundancy that'd be good.

Pretty sure the zpool was setup with 5x3TBs in a raid z2. I have 10.5TB from that. Would rather have more and less redundancy really.

In the GUI I just don't get any raid options when I try to extend the volume in volume manager, only mirror, stripe, log, cache and spare.

 

[GBillR]

I don't really want to give up that much disc space ideally. If I could have 1/4 for redundancy that'd be good.

Pretty sure the zpool was setup with 5x3TBs in a raid z2. I have 10.5TB from that. Would rather have more and less redundancy really.

In the GUI I just don't get any raid options when I try to extend the volume in volume manager, only mirror, stripe, log, cache and spare.

So someone smarter than I will have to figure out why the GUI is doing that...

 

[Glorious1]

So someone smarter than I will have to figure out why the GUI is doing that...

Yeah I have no idea either. Did you go through the documentation carefully and follow the steps? My impression of that vdev/pool wizard was that it's pretty confusing and a good place to make a major blunder if you're not careful.

 

[gpsguy]

I'm fairly certain that @Chug could extend the volume as he proposes, from the GUI.

By default, the Volume Manager (http://doc.freenas.org/9.10/storage.html#volume-manager), add some seatbelts in an effort to prevent users from screwing up their pool.

For example, if he currently has a 5 disk RAIDz2 volume, the ideal way to extend it, would be with another 5 disk RAIDz2 vdev. Done that way, the volume (comprised of 2 vdev's) can withstand the loss of 2 drives in either vdev, without losing the data. Now, if the OP extends his volume with a 4 disk RAIDz1 vdev, he can only afford to loose one drive in that vdev.

Later, 2 disks in the RAIDz1 vdev die and the entire volume disappears. We discover there are no backups. The user says, "But, I was using RAIDz2". He was, but extending the volume with the new RAIDz1 vdev weakened the redundancy.

With the 6TB drives, *I* would put the 4 drives in RAIDz2. Yes, you'll loose 12TB of space to parity, but you'll still be protected against the loss of 2 drives in this vdev.

If you still want to proceed with the RAIDz1 idea, click on the icon in the lower right hand corner as seen in "Fig. 8.1: Creating a ZFS Pool Using Volume Manager" of the documentation. See the URL above.

There is a case or two, where I would use the option. But this isn't one of them.

If you go that route, ensure that you have good backups.

 

[Scharbag]

As for the title of the post, RAID is never a backup or a "backup" :) Backups are a copy of your data on some other physical media. Best case, in another physical location.

But backups can be made from RAID...

:)

 

[Chug]

Thanks for the replies. I'm happy with Raid z1, its 1 drive more redunancy that I had before.

I added the 6TB as another zpool and copied the data from the 3TB pool over to it as the latter was full.

Now trying to add the 5x3tb as a new vdev to the 4x6tb and get this "You are trying to add a virtual device consisting of 5 device(s) in a pool that has a virtual device consisting of 4 device(s)"

There is a red exlamation mark next to a blank box which says this value is required, but I have no idea what value it wants and can't find any reference to it on the documentation.

I'm half inclined to have 2 separate zpools for the 2, aside from not being able to get them going as one, with 2 zpools, my understanding is there is less risk as explained above it'll only take out one zpool if 2 discs fail.

Cheers