To ZFS or not to ZFS? Help needed with an old desktop conversion...

[doncarlos69]

Hi Guys

I have an old desktop PC which I would like to convert using FreeNAS so that I can store my videos and MP3s, and perhaps some photos as well. I'd like to be able to hook it up to my PS3, laptop and phone, and perhaps one other device, but doubtfully more than 2 at a time.

I will require approximately 2.1TBs at this stage, so I am thinking of doing either a RAIDz with 3x 2TB drives or RAIDz2 with 4x 2TB drives.

The CPU is a Dual Core E5300, but the problem I think would be more the RAM, I am only able to upgrade to a maximum of 4GB with my current mother board, will this be sufficient?

The other thing that I wanted to know was about ZIL. I have 2 old 80GB IDE HDD that I could mirror, to keep the log files, would this be necessary?

I do want to have redundancy, and don't want to lose my data...

Suggestions would be greatly appreciated.

Cheers

Carl

 

[joeschmuck]

Re: To ZFS or not too ZFS? Help needed with an old desktop conversion...

Thanks for asking before you leaped. First the ZIL, forget about ZIL and LOG drives, they will not benefit you and don't benefit most people in a home environment.
Second you could run a small ZFS system on 4GB RAM just fine but you would be limited in how many hard drives would be recommended to be used. If your data is critical then ensure you back it up on DVD, even a NAS can have lightning strike it. Four drives in a RAIDZ2 or RAIDZ1 would be fine, you do not need to stick to the ZFS rules of thumb for a small system like this with respect to the number of drives for a given Z level. Make sure you use the 64 bit version (assuming your CPU supports 64bit). If you are forced to 32 bit then you will hit a tuff spot so lets hope that isn't in your future.

 

[doncarlos69]

Re: To ZFS or not too ZFS? Help needed with an old desktop conversion...

Thanks for asking before you leaped. First the ZIL, forget about ZIL and LOG drives, they will not benefit you and don't benefit most people in a home environment.
Second you could run a small ZFS system on 4GB RAM just fine but you would be limited in how many hard drives would be recommended to be used. If your data is critical then ensure you back it up on DVD, even a NAS can have lightning strike it. Four drives in a RAIDZ2 or RAIDZ1 would be fine, you do not need to stick to the ZFS rules of thumb for a small system like this with respect to the number of drives for a given Z level. Make sure you use the 64 bit version (assuming your CPU supports 64bit). If you are forced to 32 bit then you will hit a tuff spot so lets hope that isn't in your future.

Thanks joeschmuck for getting back to me.

If I added another vDev of similar config to the first, do you think I would still be alright in terms of my RAM? My data isn't critical, it's music, movies and series etc, but stuff I wouldn't like to lose. Short of backing up everything, what would my next best option be? To make regular backups of the ZIL? I assume even though there are not dedicated drives for them they will still exist, right?

The CPU is 64bit, fortunately, so I am alright there. Something else I read about and wanted to ask was about RAIDZ1 vs RAIDZ2. What are the chances of a drive failing while it is rebuilding as a result of a drive failure? Basically someone described a scenario like this: You have a RAIDZ1 configuration with 3x 2TB drives and one of them fails. A replacement drive is organised and put in to rebuild the data. In the process of rebuilding the new drive, one of the other drives fails because they are working so hard to rebuild the data. Is this something I need too worry about, bearing in mind the pool will be used predominantly for reading, with not as many read/ writes? I want to safeguard my data, but also don't want to waste the space I would gain from using RAIDZ1 instead of RAIDZ2. Is RAIDZ2 overkill or necessary?

 

[joeschmuck]

Re: To ZFS or not too ZFS? Help needed with an old desktop conversion...

There is a lot of personal preference when building a FreeNAS machine because you do have options.

First, with 4GB of RAM you should be fine running 4x 2TB hard drives in any configuration you desire. If you add more hard drives under ZFS then it's my opinion you need more RAM, 6GB but from what I understand it is very dependent on what you are doing with the NAS. If there is any heavy load on both pools then you might have an issue with speed.

RAIDZ1 or RAIDZ2, up to you. If you feel like you may want to use this NAS for reliable long term storage then I recommend RAIDZ2 and all the drives you plan to throw at it up front, however if you're like most of us who just wants to get started and are unsure of your requirements, start with RAIDZ1. One thing I do not recommend, same as many others, don't use 3TB drives, they would take a very long time to resilver should you have a drive failure and if you had a second drive failure, data loss. After a few months or maybe even a year you might want to change your configuration and that shouldn't be a problem. That's what I did, just took a few years to get to my final configuration.

You said ZIL again, I just wanted to ensure you know that a ZIL will not help you at all, nor will a LOG. Don't waste your efforts unless you just want to play around and do some testing.

Hope that helps.

 

[cyberjock]

Re: To ZFS or not too ZFS? Help needed with an old desktop conversion...

You don't seem to understand what the ZIL does. As joeschmuck said, I'd never recommend a ZIL before you add more RAM. I have no idea why you think backing up the ZIL will matter at all. The ZIL is strictly written to during normal operations. And by strictly I mean never ever ever read from, except in one situation. If the server loses power and is later booted up the ZIL will be read from only to verify that all the writes to the zpool were completed before the unexpected shutdown.

Aside from that, more RAM should be far far higher on the priority list than a ZIL or L2ARC.

 

[doncarlos69]

Re: To ZFS or not too ZFS? Help needed with an old desktop conversion...

Thanks cyberjock and joeschmuck.
Suggestions taken and noted.
No more ZIL talk.

Now to just get some drives.