Old AMD build - to run video service using EMBY

[Napalm]

OK before it's said yes I read some other threads first - and the supposed hardware guide.

However - I plan on using my current desktop computer setup that I have as my first build at this. SO conventional wisdom aside - I'm not buying new hardware of that cost or ability to try this. If I was going to spend all that money from scratch I wouldn't be here I'd have already bought a Qnap or Thecus device - or maybe even the cheaper Ix system box.

Processor - AMD PhenomII X4 970.
Motherboard: MSI - 870A-G54
Ram: 12gb dual channel DDR3
Disabling Audio and removing Video cards
PSU - Thermaltake 80Plus certified 450W. I forget the model number.

Hard drives - Samsung 840Pro SSD
5 - 2tb - HGST 7K2000 drives. I think I have that right it's either 2000 or 3000 I don't have them yet.

Assuming a RaidZ2 setup.

Plan is to store videos on this for use in the home streaming, maybe put music on it, and keep other odds and ends. I have a NAS box now that I keep the odds and ends and personal pictures on - mostly to be the first step auto backup for my mobile.

 

[Chris Moore]

You already said that the hardware you have is what you are using and you will not buy any different hardware, so what are you asking?

Sent from my SAMSUNG-SGH-I537 using Tapatalk

 

[Napalm]

Well crap I shouldn't have posted so late.

Yes I missed the question bit.

1) Performance of raidZ2 - I'm not familiar with zfs and raid Z but I under stand it's analogous to Raid 5 and 6. SO to that end - would I notice any performance benefits to running Z2 or Z1?

2) Hard drive space - I know I'm giving up some usable space by running Z2 so as to have a bit more redundancy - but is it really worth it? People that run media streaming on your boxes - which raid version do you run?

Again all my sensitive stuff will be on a separate NAS box running mirror mode - and I keep it backed up regularly offsite.

3) Virtual Machines - Do any of you guys run EMBY server on your FreeNAS machines? If so it is a resource hog, does it run well - do you need the server to transcode?

 

[Inxsible]

1) Performance of raidZ2 - I'm not familiar with zfs and raid Z but I under stand it's analogous to Raid 5 and 6. SO to that end - would I notice any performance benefits to running Z2 or Z1?

The difference is that when you have RaidZ1, you only have 1 disk worth of redundancy and if 1 drive fails and you are in the process of re-silvering, chances are good that another drive might fail leading to the loss of the whole pool. That is why RaidZ2 is recommended because you have a 2 drive redundancy.

2) Hard drive space - I know I'm giving up some useable space by running Z2 so as to have a bit more redundancy - but is it really worth it? People that run media streaming on your boxes - which raid version do you run?

Almost everyone here will recommend that you run RaidZ2 due to what I explained in Q1

Again all my sensitive stuff will be on a separate NAS box running mirror mode - and I keep it backed up regularly offsite.

Then you can take the chance of going RaidZ1, I guess but why would you still want to lose a pool and rebuild it again from the backup just to save 1 drive worth of space?

3) Virtual Machines - Do any of you guys run EMBY server on your freenas machines? If so it is a resource hog, does it run well - do you need the server to transcode?

I run Emby but not as a Virtual Machine. I just installed the plugin available. I have Pentium G3240 on my NAS and I would say it runs pretty well. No hogging of resources. It does take up some space for the metadata -- but that would depend on how many media files you have. I also run couch and transmission from the NAS and I can stream to 2 to 3 devices simultaneosly. My pentium cannot handle more than 1 transcode however. I keep my media in a format where I don't have to transcode very often. But if you see yourself needing transcode streams then you would need a much better processor than what I have.

 

[Chris Moore]

Performance of raidZ2 - I'm not familiar with zfs and raid Z but I under stand it's analogous to Raid 5 and 6. SO to that end - would I notice any performance benefits to running Z2 or Z1?

It isn't about performance. If you have a single vdev (drive group) in your array, it will have basically the performance of a single drive. The purpose is redundancy so you can suffer a drive failure without data loss. RAIDz1 has just one drive of redundancy, where RAIDz2 has two drives and RAIDz3 has three drives.

Hard drive space - I know I'm giving up some useable space by running Z2 so as to have a bit more redundancy - but is it really worth it? People that run media streaming on your boxes - which raid version do you run?

I use RAIDz2. I previously tried RAIDz3 and I felt it was not as suited to my needs, but I keep two cold spare drives on hand for each drive size that I use.

Again all my sensitive stuff will be on a separate NAS box running mirror mode - and I keep it backed up regularly offsite.

Backups are good.

Virtual Machines - Do any of you guys run EMBY server on your FreeNAS machines? If so it is a resource hog, does it run well - do you need the server to trans-code?

I use Plex and it runs fine for what I do including some trans-coding during playback for devices that need a different resolution than the source file. That is dependent on the equipment you use and I don't think you will get very good performance from the hardware you have selected.

 

[Napalm]

Thank you both. I was under the impression that because z2 had the extra drive of redundancy - provided all drivers were working right - you would get some throughput increase because it would span the reads over another drive. So that if you were getting 65Mb/s on z1 you might get 75 on Z2 because of the other drive - but only when all 4 were in good nick.

I ended up buying 5 drives anyway - and based on this post will probably order 2 more mentioned to keep another ready spare.

 

[Inxsible]

I ended up buying 5 drives anyway - and based on this post will probably order 2 more mentioned to keep another ready spare.

You probably already know this, but you cannot add drives to an existing vdev. So if you create a vdev with 5 drives today, you won't be able to add more to it. You can add a new vdev to the pool, however. But 2 drives means it will have to be a mirror if you want any redundancy in that vdev. And I, for one, don't like mixing RaidZx vdevs with mirror vdevs or even different RaidZx setups together.

You might want to plan your storage layout beforehand.

 

[Napalm]

not planning to add to it - like the guy above said - keeping a cold spare incase one dies. so I have it in hand for rebuild instead of waiting to get one in hand.

Or did I read that wrong too. If I had a drive go wonky on my z2 pool - I can put in same capacity drive and rebuild the pool.

 

[Inxsible]

not planning to add to it - like the guy above said - keeping a cold spare in case one dies. so I have it in hand for rebuild instead of waiting to get one in hand.

Or did I read that wrong too. If I had a drive go wonky on my z2 pool - I can put in same capacity drive and rebuild the pool.

Keeping cold spares is good. However 1 cold spare should be sufficient instead of 2 especially if you are going with RaidZ2.

If a drive does go wonky, you can put in the same capacity drive or a bigger capacity drive and rebuild the pool. If you do put in a bigger capacity however, you won't see the increase in space until you replace all the drives in the vdev to the bigger capacity.

Hope that makes sense.

 

[Napalm]

Does indeed thank you for the confirmation. I started to worry.

 

[Jeff Armstrong]

Z2 will work with 5 drives but it is generally considered best practice to work in powers of two plus the parity drives, I.e p + 2^n. So for Z1 p is one and the optimum VDEV config would be 3, 5, 9. I have not experimented with that so not entirely sure how important at the moment.

Anyway, for Z2 the optimum number of drives is 4, 6, 10

You may consider throwing a 6th drive in there.

 

[Inxsible]

I have read that too, but I also read that it's best to keep the vdev size to max 8 drives for RaidZ2. To put both of them together RaidZ2 can only be used with 4 or 6 drives then?

 

[gpsguy]

I don't understand what you mean by "put both of them together".

Depending on your tolerance for risk a 10 disk RAIDz2 vdev might be acceptable. I wouldn't go beyond 10 drives.

Often, users might choose RAIDz2 vdev widths, based on the number of drive bays in their chassis. For example, if you had a 24 bay chassis, one might choose 3 x 8 disk vdevs or 4 x 6 disk vdevs. If one had or was buying all 24 disks up front, 3x8 disks, would have less overhead than 4x6 disks. OTOH, if one was expanding their pool over time, one might go with 6 disk vdevs. A six disk RAIDz2 vdev is one of the sweet spots.

Unless you have a small chassis, I don't recommend 4 disks RAIDz2 vdevs. One looses 50% of storage to parity.

I have read that too, but I also read that it's best to keep the vdev size to max 8 drives for RaidZ2. To put both of them together RaidZ2 can only be used with 4 or 6 drives then?

 

[Napalm]

I think what he's saying is - if one recommendation is to use even number drives and another good practice is to keep vdev's under 8 drives - then logic dictates a z2 array should run 4 or 6 drives.

I'm starting to think I will start with 4 drives on my pool and see how it plays.

 

[Jeff Armstrong]

Yes, Z2 4 or 6 drives fits the parity plus power of two rule of thumb.

Maybe one of the gurus can comment on/answer this. If you run Z2 with 4 disks per VDEV then the question becomes -- is that more advantageous than running a 2+2 mirror?

Running mirror should provide slightly better performance since parity would not need to be calculated, but if you lose a disk in a 2 + 2 mirror, then you run the risk if the mirror of the damaged disk fails during resilvering you would lose the entire pool where as in a Z2 4 disk VDEV you could lose any one of the remaining three and still be safe? Is this correct? This cannot be the first time some noob asked such a basic question, it probably is answered elsewhere in the forums, I will go search :)

 

[Inxsible]

Yes, Z2 4 or 6 drives fits the parity plus power of two rule of thumb.

Maybe one of the guru's can comment on/answer this. If you run Z2 with 4 disks per VDEV then the question becomes -- is that more advantageous than running a 2+2 mirror?

Running mirror should provide slightly better performance since parity would not need to be calculated, but if you lose a disk in a 2 + 2 mirror, then you run the risk if the mirror of the damaged disk fails during resilvering you would lose the entire pool where as in a Z2 4 disk VDEV you could lose any one of the remaining three and still be safe? Is this correct?

Yes this is correct.

This cannot be the first time some noob asked such a basic question, it probably is answered elsewhere in the forums, I will go search :)

It is.
https://forums.freenas.org/index.php?posts/448280/

 

[gpsguy]

You guys need to stop agonizing over exact numbers/forumla's, since ZFS compression is on by default, in FreeNAS. See - https://www.delphix.com/blog/delphi...or-how-i-learned-stop-worrying-and-love-raidz

Yes, Z2 4 or 6 drives fits the parity plus power of two rule of thumb

One can make an arguement either way, whether to go with RAIDz2 or striped mirrors. For best performance, the latter will give you more IOPS. For general use RAIDz2 will give you better protection. Either way, you should be doing backups.

 

[Jeff Armstrong]

One can make an arguement either way, whether to go with RAIDz2 or striped mirrors. For best performance, the latter will give you more IOPS. For general use RAIDz2 will give you better protection. Either way, you should be doing backups.

Indeed, I am data paranoid, I keep triplicates of all my critical data and duplicates of the "non-critical but PIA to recover" data.

 

[Chris Moore]

I think what he's saying is - if one recommendation is to use even number drives and another good practice is to keep vdev's under 8 drives - then logic dictates a z2 array should run 4 or 6 drives.

I'm starting to think I will start with 4 drives on my pool and see how it plays.

I think that 6 or 8 drives is the sweet spot for RAIDz2. I have an archive server at work where I put 15 drives in each RAIDz2 vdev and the resilvers are quite slow. My system at home with only 6 drives in each vdev resilvers in around 3 hours where the one at work takes around 3 days. It does have more total data and 6TB drives instead of 4TB drives, still, I don't think the difference is all down to the amount of data...

Anyhow, If you can, I would suggest that you go with 6 drives to start. If you need to expand, add a second vdev of another 6 drives. That is the expansion path that I followed and it worked well for me.

 

[Inxsible]

RaidZ2 configuration is something that I have to think about soon too. I have a 12 drive chassis and I could do

1. 6 drive vdev initially + 6 drive vdev later
2. 8 drive vdev initially

Option 2 would be because I also have a 1U server chassis with 4 drive bays that I would like to convert into a JBOD unit running off of my main NAS eventually thereby giving me a total of 16 drives instead of 12.

Should I go for 6 drive or 8 drive vdevs?

 

[Napalm]

Talk about learning something new each round - so you're saying there is a compression algorithim running with ZFS also. Is that something that can be turned off?