Memory utilization

[otakucode]

Hello all. I just installed FreeNAS 8 a week ago and after some initial difficulties (mostly hardware, not FreeNAS fault) I got it running. This is my first go-round with freenas, my fileserver previously ran XP (blah, box was not intended to be a fileserver originally and did not get rebuilt as it morphed into one).

I hadn't looked at the 'minimum requirements' before installing. My box is an AMD Athlon64 X2 3800+ with 1GB of RAM, booting from a USB stick. Highpoint RocketRAID 1740 controller with 4x 2TB Samsung Spinpoint F4 drives (in a RAID5), and 2 standalone 2TB drives. I notice now that the min reqs page says 4GB of RAM is necessary. I am not using ZFS and will not try it until I have upgraded to at least 4GB of RAM, but that won't likely be for awhile.

So, my concern is that I am frequently seeing 99%+ memory utilization. Right now, there is 4MB of RAM free on the system. Right after a reboot, I've got about 200MB free. Should I expect freenas to eat more RAM as it stays up? I'd prefer to almost never reboot the box if possible. Is there anything I can turn off, such as disabling ZFS support somehow? I know about editing config files where they are loaded into the ramdisk from, I just don't know what to edit.

Right now, the processes eating significant RAM seem to be (I'm just checking top... is there a way to get top to display processes by RAM usage? Or perhaps another tool? I'm very familiar with *nix systems, but from a development rather than sysadmin POV): python using 105M, smbd using 102M, rpc.statd using 263M. I have SSH, FTP, CIFS, NFS turned on as far as services go. I've got 3 volumes, each shared both as a samba share and an NFS share (I've got a few Ubuntu clients that mount the NFS shares). Am I simply being unrealistic wanting to run this configuration with only 1GB of RAM? Should I consider using freenas 0.7? If so, will everything port over? My volumes are UFS volumes.

Thanks in advance for any info.

 

[esamett]

I am a few weeks ahead of you on the noob line. Let me share my experience and the answers i have received.

You have a 64 bit cpu and so can run the 64 bit freenas (amd64.) There is a memory management issue with the 32 bit build (i386) and I do not recommend it if you are using zfs.

You are using a couple of hard drives and so the advice applies: 1 GB not enough, 2 GB kinda adequate, 4GB better. My system ran OK with 3 drives with 2GB GB but really bogged down with 8 drives. It didn't matter what CPU I used. The system loosened up with 4GB ram installed. Others have written that more ram (6-8GB) improves performance to the next level.

DDR systems are practically limited to 2GB (2x1), while DDR2 systems are practically limited to 4GB (2x2) due to the cost of memory sticks. You may have a DDR2 system and I found a vendor who sells basic 4gb ram for $48 shipped.

In summary, I would recommend 64 bit build and 4gb ram and see how it performs for you. If you can't afford more ram stick to UFS which is more limited in freenas 8 than freenas 0.7.

good luck.

 

[Credo]

I'm curious about the 64 bit version mentioned above. I'm running Dual Xenon. Should I still be using the i386, or is there a better version for me to use? I've had the system reboot itself a couple of times under heavy load when copying files to the NAS.

NAS Setup
Dual Intel Xenon E5140 @ 2.33Ghz
4GB DDR2 PC1333Mhz Ram (an extra 4 available to install if necessary)
2 x LSI Logic SAS Raid controller cards
1 x 156Gb SATA
1 x 500Gb SATA
4 x 147Gb SAS - RAID Z Format
4 x 2Tb SATA - RAID Z Format
2 x Broadcom Gigabit Ethernet lagg configuration


Thanks in advance.

 

[countingways]

I am experiencing like kind issues. The reporting page show negligible memory usage at boot. After performing tasks in iTunes (importing podcasts and music files, rebuilding library, etc.) I see a large spike in cached memory and reduction in free memory. Its been awhile since I used UNIX and am not sure what 'cached' memory refers to. This however, is the type of behavior I see on windows systems when there is a memory leak. When I run top() I see a bunch of python and getty commands with CPU utilization ~100% idle. I am using UFS and only have the CIFS service enabled as I am currently testing FreeNAS to see if it will do what I want.

NAS Setup:

Board - gigabyte GA-MA78LMT-S2H
CPU - AMD Phenom II X2 560 3.3Ghz
2 x 2 GB Corsair DDR3 @ 1333 Mhz
1 seagate 250 GB 7200RPM sata drive with ACHI turned on.
OS AMD 64 bit version on 2 Gig USB memory stick

 

[survive]

Hi guys,

There are a lot of concerns listed here. I'll try to address some of them the best I can.

As far as memory utilization goes, you *want* the system to use every bit of memory that it can! Don't stress it if your system is showing all your memory in use but it is running well! All that memory that it shows used as "cached" include files the system has in it's read-ahead buffer ready to go.

If your processor supports it you want to use the amd64 builds, even if you have less than 4GB of RAM. Read this, especially the "Pros & Cons" section:

http://en.wikipedia.org/wiki/64_bit

otakucode: You are in a particularly bad spot because DDR memory is simply to darn expensive per Gig. I just checked on Newegg and it looks like DDR is about 8X more expensive than DDR3! If you can score some more RAM off Ebay for a good price it might be worth it to try to get more, but it very quickly becomes a better deal to get some newer hardware.

Worse, since you are booting off a USB key some of your memory is being used to create some ram drives for FreeNAS itself to run off of. I just checked my system and it looks like there is about 80MB used for these drives.

My recommendation: If you are running FreeNAS 8 take a look at the AMD E-350 boards. For about $200 you can get a board & 8GB of ram (maybe include ~$50 for a Corsair CX430 PSU) and simply gut your 3800X2. This will also allow you to toss the PCI SATA card and get your drives off the PCI bus.

Credo: By all means give the amd64 build a try. If you want just back up your config, install to a different USB key, boot & upload your config. That way you have a path back to a working system.

-WIll

 

[otakucode]

Thanks for the responses. I should have mentioned, I am running the amd64 build. One of the issues I ran into was that I originally installed the 32-bit version because I thought the fileserver had a different (and only 32-bit) processor. When I saw it had an Athlon64 in it, I went ahead and got the amd64 build. I originally upgraded, but some things break if you do that even though freenas will offer to do it and not complain (things like the RRD graphs stop working because they were generated on a different platform).

I had come to the same conclusion about not wanting to waste the money on RAM for the old system. For the same price as 4GB of DDR, I could get a dual core Atom-based board with 4GB of RAM on it. I particularly like that approach because it would cut down on the power usage. My freenas box will never run anything of significant aside from fileserving duties, so I'm not worried about CPU utilization. I will probably keep my HighPoint RAID card though, as its offloading of the XOR processing is what keeps CPU utilization low. I doubt I will seriously pursue ZFS for quite awhile yet, so by the time I want to try it I may be able to transition one of my other beefier boxes into that role, so I think the Atom setup might be a good fit.

 

[countingways]

Thanks for the info. My transfer speeds were far below what I am targeting, but I believe that is mainly due to a wireless G path the data currently has to take. The NAS and PC both have Gbit ethernet but the PC communicates wirelessly to the router. NAS is hard wired. I'll hard wire both today and see if I notice a performance improvement, which I expect.