Advice Needed

[M.A.H]

Hi,
I am building my first freenas server out of my old pc and needed some advice on which raid option to go for as I have never used raid before.
Here are the specs:

CPU: AMD Athlon X2 dual core 2 GHz
Motherboard: Asus A8N-SLI Deluxe with 2x Gigabit Ethernet
RAM: 4GB DDR
Standard PCIE Radeon HD Graphics
HDD's
2x 3TB Seagate
3x 1TB Hitachi
1x 500GB Seagate
1x 500GB Hitachi

I have read that it is recommended to have 1GB ram to 1TB hdd because the ZFS file system uses alot of ram but I dont mind if its slightly slow because this server is only going to be used for backups only and switched on every 2 or 3 weeks for backups then switched off. My motherboard has 8 sata ports in total but 4 of them are for raid and the other 4 are for normal use. I know I must put the setting to JBOD in bios so I can use all 8 sata ports as normal use and let freenas software to handle the raid. I have about 6TB of data to backup and with the HDD's I have totaling 10TB I have 4TB for redundancy. I don't know which raid setup would give me the storage space needed with redundancy. Is there some sort of a chart where I can check 10TB or any size of hdd's with raid x would give me x amount of storage space and x amount for redundancy. I may even need more hdds to handle the redundancy so my question is which raid setup would suit me best and would allow me to have enough storage space with redundancy?

Also If I change the hardware in the future with new cpu, motherboard, ram will it effect the data in any way? Do I have to reinstall freenas? Or can I just swap out the old hardware with new hardware and it works normally.

Thanks

 

[cyberjock]

Mixing and matching hard drive sizes with ZFS doesn't work well. You are always limited to the smallest drive, just as a hardware RAID would be.

 

[gpsguy]

You *could* go with 3 sets of mirrors, 2*3Tb + 2*1Tb + 2*500Gb and maybe end up with ~4Gb usable space. I'd dump all but the 3Tb drives. Add 1 or 2 more, for RAIDz1, or preferable RAIDz2.

Given the 4Gb of RAM and age of the pc, I'd look at newer hardware and start with no less than 8Gb of RAM.

One of the beauties of FreeNAS is the ability to change hardware easily. Depending on whether you've kept up with OS upgrades, you could either keep the same boot device or install a new version of FreeNAS, import your volume, and restore your configuration file.

 

[titan_rw]

I know mixing vdev types is generally not recommended, but you could do 2x 3tb in mirror, and 3x 1tb in raidz1. I'd forget about the 2x 500. Not really worth it putting them in. This would give you 5tb (hd manufacturer size) of usable. A "df -h" on the resulting pool will probably show 4.2 tb available.

This still leaves you with a single parity pool. Replacing a 1tb drive relies on the 2 other 1tb drives to operate flawlessly. As with replacing a 3tb drive, pray there's no problems with the other during rebuild.

You might be able to get this to run on 4 gigs of ram, but I'd imagine there'd be lots of tweaking / tuning to do. I'd be concerned with data loss. If at all possible, use 6 or 8 gigs of ram.

 

[M.A.H]

Thanks for the replies.

I was also thinking of not enabling redundancy because the original data is still going to be stored on the other PC's. This server is just going to have a backup copy of the data and only switched on just for backing up then switched off. So either way if the original HDD or the server HDD fails I will always have a copy of the data. Is this a good idea? Has anyone have any experience with this type of set-up?

If I don't have redundancy would all HDD's be combined into one volume of 10TB? or can I have each HDD separate. I don't want to combine all HDD's together because of the danger if 1 drive fails the file system will be lost so all data is lost. Any suggestions?

 

[titan_rw]

You *could* do that. It's a perfectly valid zpool configuration. However it's definitely not recommended. Even if it's just a backup nas, I wouldn't do it.

If you don't need redundancy, then I'd simply have separate shares setup on each individual drive. You'd still get the capacity of all the drives, you just have to deal with individual shares for that capacity.

And if you're using the drives individually with separate shares to access them, I'd probably bypass zfs and stick with ufs. That way your 4 gigs of ram should be sufficient.

 

[M.A.H]

I have just read through cyberjock's guide which is excellent for a noob to understand. As I understand my use of the server I don't need ZIL or L2ARC. Can I have a set-up with 1 HDD in 1 Vdev in 1 Zpool so I will have 7 HDD's in 7 Vdevs in 7 Zpools? So if any 1 HDD fails it will not effect any other HDD. Will this set-up consume alot of RAM?

Can I have control on which HDD to share to a specific PC on the network? or share all HDD's to a specific PC on the network.

I am trying to keep future upgrades in mind. When I have better hardware the ideal file system would be to go with ZFS. If I use UFS I believe I cannot convert UFS to ZFS without the need to back up all data from server and start again.

 

[titan_rw]

Yes, each drive being in a separate zpool will limit drive failure to data on that drive. None of the other drives will be affected.

As far as sharing with specific pc's, yes you can do whatever you want. Either with permissions on the filesystems, or with ip access lists through samba. Lots of different way to set things up.

Setting up freenas to use these hard drives in the first place is a kind of system you won't really be able to expand. So picking ufs instead of zfs isn't going to make that much of a difference down the road. You'll have to rebuild all your drives / zpools anyways. UFS has much less overhead than zfs, and since you wouldn't have any redundancy for zfs, I wouldn't bother. Using zfs on a single drive would still get you snapshots, and replication, but I assume you're not likely to need that. Also, zfs on a single drive will still inform you of any silent data corruption from the drives, it just won't be able to do anything about it. With each drive setup individually, I'd just use ufs. Then your memory issues won't be an issue.

 

[M.A.H]

How does UFS data integrity compare with ZFS? If its the same level I will go with titan_rw's suggestion of having the UFS file system and set-up the server with 7 HDD's in 7 Vdevs in 7 Zpools. I will be using an 8gb usb for the freenas installation also I have read about installing programs on freenas, are these add-ons or full programs? Is samba a sharing program that needs to be installed or is it built in freenas?

 

[cyberjock]

UFS has no ability to self correct any errors or identify/correct silent corruption. That's what makes ZFS so awesome. But for single disk applications, ZFS can only identify issues, it cannot repair them.

 

[M.A.H]

Thanks for the help. I will first test the server with ZFS if the speeds are ok then I will leave it if not I will switch to UFS. Another thought I had was since my motherboard has 2 gigabit ethernet ports is it worth teaming them together? Does freenas support this? Or do I have to set it up through my router/switch?

 

[cyberjock]

Please start a new thread since your new question is not related to the old question. I will tell you that if you read the manual you'd have the answer to your question.

 

[Aaron Petterborg]

I know this thread is old-sauce but I like the idea of making my first post here just a response to a thread I found searching rather than a n00bish-looking original post. I'm debating between using my own A8N-SLI Deluxe (this one: www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1179727) and using my sister-in-law's desktop she rudely left at our house to start my FreeNAS project. Some bullets:

• A8N-SLI Deluxe maxes out at 4 1GB DIMMs
• Sister-in-law's compy may max out at 16 GB
• A8N-SLI Deluxe has 4 SATA II slots controlled by a little onboard nVIDIA RAID chip and 4 other SATA II slots controlled by an Intel chip
  • If I opt with this mobo I'm just going to do software RAID 5 (or whatever the ZFS equivalent of striping with distributed parity is called) in a 4+1 configuration since anything but that doesn't take full advantage of the standard (4+1 or 8+1)
  • My worry is the bottleneck of the software striping. Will bridging between the two controllers in this way present a huge bottleneck, or can I bet on decent backend speeds (I'm considering 5 1TB WD blues, model WD10EZEX, 7.2K RPM, 64 MB cache, SATA III in case I want to migrate to something prettier in the future). Am I better off having 3 on one controller and 2 on another, or 4 and 1? I'm thinking if the bandwidth is the same splitting it closer to in half with the 2 on the slower interface (haven't found this out yet) and 3 on the faster would be good.
• I'm wondering if it's better to just go buy me a couple of PCIe SATA III controllers on the mini-PCIe setup and stick those into the more modern sister-in-law's computer. I just hate looking at 8 onboard SATA slots and ignoring them. It's such a beautiful old mobo.

My main question is: Would the striping speed I'd gain on the backend from the 4 spindles make up for the performance hit from only 4GB of RAM? Would setting up swap space on SSD/EFDs in the remaining SATA slots be a neat idea if I wanna keep using this mobo?

 

[cyberjock]

The A8N-SLI is out of the question. 9.3, which is due in less than a week, requires 8GB minimum.

Swapspace means nothing for FreeNAS except emergency space if you've screwed up (or there's a code problem).

You aren't going to get out of the hard limits of FreeNAS. To be honest, neither of the hardware you are listing is suitable to FreeNAS. You should read more of our stickies and documentation.

 

[Ericloewe]

I'll add that, even if the motherboard supported 8GB, it's best to stay away from any motherboard with any sort of Nvidia controller.

 

[Aaron Petterborg]

Thanks for the information, and for directing me to the stickies.