ZFS is not using RAM

[kumuller]

I have a Stripe Pool:

8 * 2TB WD 4k Sektors

8 GB Ram
2,5 GB Swap
Full Installation Rev. 358

When i copy NAS to PC Performance is about 100MB/s via SMB. (Testfile: 1 *.mkv with 5GB)

But when copy from PC to NAS the Performance is during the copy between 45 - 120MB/s and the WebGUI says that the System only use ca. 20% of the Ram.

With FTP the same.

With ZFSkernTune the same.

Here my loader.conf

kernel="kernel"
bootfile="kernel"
kernel_options=""
kern.hz="100"
hw.est.msr_info="0"
hw.hptrr.attach_generic="0"
kern.maxfiles="65536"
kern.maxfilesperproc="50000"
kern.cam.boot_delay="8000"
autoboot_delay="5"
isboot_load="YES"

# ZFS kernel tune
vm.kmem_size="6656M"
vfs.zfs.arc_min="5120M"
vfs.zfs.arc_max="5120M"
vfs.zfs.prefetch_disable="1"
vfs.zfs.zil_disable="0"
vfs.zfs.txg.timeout="5"
vfs.zfs.vdev.max_pending="10"
vfs.zfs.vdev.min_pending="4"
vfs.zfs.write_limit_override="0"


Why ZFS is not using more RAM? Or is the WebGui wrong by telling me using 20% Ram?

Regards
Jens

[torf74]

You are using the 64-bit version right?

[kumuller]

Yes. It is the 64Bit version.

[lux]

try vfs.zfs.prefetch_disable="0"

don't disable prefetch with 8Gb RAM

my loader.conf

Code: Select all

#ZFS kernel tune
vm.kmem_size="7G"
vfs.zfs.arc_min="5G"
vfs.zfs.arc_max="6G"
vfs.zfs.prefetch_disable="0"
vfs.zfs.txg.synctime="2"
vfs.zfs.txg.timeout="6"
vfs.zfs.vdev.min_pending="1"
vfs.zfs.vdev.max_pending="1"

my RAM usage is 80-90% with this settings

[davidb]

I finally attempted to do some ZFS tuning now that i have updated to v431, since i have noticed that my memory usage never got above 48% or so. I loaded the module and changed it to 8GB for ram and set "disable prefetch" to false. After reboot and running some tests, although i am now using 80%+ RAM, speed has not increased overall.
I copied the "7G","5G", & "6G" settings from the post above, but left the txg.synctime,timeout,vdev.min/max_pending at the default values.
Could anyone point me in the right direction for tuning those parameters? i'd like to better understand what they do.

Any other tips for increasing speed?

Specs:
x64-full on Intel(R) Pentium(R) CPU G620 @ 2.60GHz
ASRock H77 Pro4/MVP Bios: P1.10 03/19/2012
8GB Kingston DDR3@1066MHz
Boot Drive: SSD 32G|CRUCIAL CT032V4SSD2
Storage: 4x WD Red 2TB drives in RaidZ1
Network: NIC INTEL|EXPI9402PTBLK DUAL GigaBit (lagg as LACP)

[erezsolan]

just a follow up question; when using the webgui module, it claims no config file is found (i guess loader.conf?).

Even if I create it under /boot/ it disappears after a reboot.

I'm using a LiveUSB latest build (431), booting from a DoK and saving config on another DoK.

[malouja]

To load your loader.conf, you should unmount the /cf mounting point from your USB key. Let's check by running the command mount.
Remount it with this command : mount /dev/da0a /cf
and change the /cf/boot/loader.conf
Reboot.
That's all.

[ku-gew]

ZFS doesn't use cache for streaming loads. If you copy a file and then copy it back, it'a streaming usage and cache is useless (or almost useless). My server is the same, 4 GB but only 60% used.
If you have a lot of random reads, then cache goes up, as it should.

[raulfg3]

Even if I create it under /boot/ it disappears after a reboot.

I'm using a LiveUSB latest build (431), booting from a DoK and saving config on another DoK.

normal under liveUSB or embeded , you need full install to make changes persistent, or install zfskerntune and do changes using webgui

[Buhu]

I think using the integrated file editor will be correct to edit the file. I did this some days before !

This is my tuning for ZFS. 8GB are installed and the usage is still 88%


vm.kmem_size="7G"
vfs.zfs.arc_max="5632M"
vfs.zfs.arc_min="3584M"
vfs.zfs.txg.timeout="5"
vfs.zfs.txg.synctime="1"
vfs.zfs.txg.write_limit_override="805306368"
vfs.zfs.vdev.min_pending="2"
vfs.zfs.vdev.max_pending="10"
vfs.zfs.prefetch_disable="0"

[Buhu]

I had a little bit of testing on my 8GB RAM ....that's the outcome. Still 92% of 7543MiB and good speed.

vm.kmem_size="7568M"
vfs.zfs.arc_min="6144M"
vfs.zfs.arc_max="6144M"
vfs.zfs.prefetch_disable="0"
vfs.zfs.zil_disable="0"
vfs.zfs.txg.timeout="5"
vfs.zfs.vdev.max_pending="10"
vfs.zfs.vdev.min_pending="4"
vfs.zfs.write_limit_override="0"

[kkd]

dont forget that using is not the same as allocating.
arc min only allocates ur ram. not all the 6144M is in use. only about the 20%.

[Buhu]

On my RaidZ1 (signature ) with the old HD204UI disks i have nearly 90MB/s Read and 70 MB/s in write, tested by Crystal DiskMark. On the single ufs 3TB WDRED , 90MB/s Read and 103 MB/s write.... It's ok for me.