FreeNAS 8.3.1 w/ 2GB RAM - Seems to be working okay, Am I missing something?

[encryptedbytes]

Please forgive me if I am overly verbose, I want to provide all the relevant information to my question(s). In that pursuit, here's what I have going on...

I've loaded up FreeNAS on a system with:

CPU: Intel Core 2 Duo E4700 @ 2.6GHz
RAM: 2GB DDR2
Disk: 4x 2TB Western Digital WD20EADS "Green" SATA2 drives

...and then created a 5.3TiB RAID-Z volume from the 4 disks.

I have configured and enabled the CIFS, FTP, SMART, SSH, and UPS services. I did have Plugins enabled for a bit, but it turned out to be more involved than I wanted to get into at the moment so I turned that back off for now.

I have copied 1.1TiB of data to the volume with files of varying sizes (49K files in 2.8K folders), leaving 4.1TiB space available.

Now, I know that it recommended to have 6GB of RAM and that 4GB is passable, but with just 2GB of RAM I am not seeing any problems yet and I am curious why that may be.

I am currently:

Outgoing >>
Streaming a movie to my Android tablet (able to FF, RW, jump smoothly)
Streaming a movie to my PC (VLC, able to jump smoothly) (0.5MB/s)
Streaming a movie to a WDTV Live media player attached to my television
Streaming a movie to an app called pyTivo on my PC which reencodes the video and spits it to a TiVo (0.4MB/s)
Downloading 300GB of data via CIFS (3-5MB/s)

Incoming <<
Uploading 1TB of data via FTP (4-5MB/s)
Uploading 1TB of data via CIFS (20-30MB/s)

Currently, the load averages are 1.11, 0.84, 0.77. It is my understanding that, being a dual core system, averages up to 2.0 are acceptable, and even higher for brief periods of time.

CPU usage seems to be hovering around 50 to 60%. Memory usage is up near the 2GB limit, but swap space is not being used.

I should explain that this NAS is used as a media warehouse on my home network and that the above represents the most demand it is likely to have in regular use. Now, I'm no expert by any means, but it seems that FreeNAS is handling the situation gracefully and, despite having only 2GB of RAM, a 4-disk RAID-Z may be suitable for my needs.

Are there other metrics I should be looking at? Also, will resource demands (mainly RAM) rise as the volume fills and more files are are part of the file system? Am I missing part of the picture?

 

[jgreco]

Seems to be working okay, Am I missing something?

Speed. Eventually, stability. The FreeNAS middleware is kind of bloated and is designed around a fundamental assumption that it has a certain amount of space available, some of which is occupied by the RAMdisks used to run FreeNAS, more of which is occupied by the processes that do all the fancy stuff like stats collection, etc.

Given some tuning and patience, I would imagine that it is possible to get a FreeNAS system to run on 2GB. The biggest concerns are ZFS-related tuning values, as most of the rest of it can be swapped to disk. However, there is also some possibility for problems with ZFS import, the process that mounts a ZFS filesystem, I don't have a real good feeling for what the variables involved in that might be, and it would be annoying if you had a crash or panic or power fail and then couldn't get your FreeNAS back on its feet. Just beware.

 

[anika200]

whaaa!! You tried this after all the scary warnings, must be some kind of nut. ;) I am actually wanting to try this with 4GB so can you report back in a couple weeks and tell us how it is going?

 

[JaimieV]

My second domestic FreeNAS runs on 1gig, with 4Tb of striped ZFS space. Solid as a rock, stays up for months between OS updates. However... under normal circumstances, the only way it interacts with anything else is when it does a pull rsync from the primary FreeNAS (8Tb space, 5gig). It does have AFP running for those rare occasions I need to pull something off it, but that's annual at most. Under this minimal workload it's neither troublesome or even particularly slow. So just 1gig appears to be quite enough to handle the FreeBSD and ZFS basic requirements for 4Tb of disk space and no users.

Unless you're using dedupe (and don't ever use dedupe!), ZFS largely uses its RAM for read-ahead caching. With low RAM situations that means no cache, which means low speeds - and awful multi-user usage, so I'm mildly surprised you're getting seven simultaneous streams working together okay, I must say. Good stuff.

But if you want to see 60+meg/second transfers, bang another 4gig in.