Slow FreeNAS Writes?

[iddqd]

I just built and configured my file server, so I'm trying to troubleshoot the slow write performance I have.

FreeNAS 9.2.1

• 1 Volume shared via Windows CIFS
• Volume set up as stripe (4x4 TB = 14.4TB usable)
• Connected via ethernet to router

File Server specs

I'm trying to transfer data from a USB external drive over the network into the File Server. Right now I'm writing around 1MB/sec, but I was expecting much more than this.

 

[mervincm]

What do you see if you copy a single multi-gigabyte file from the notebook/desktop's local HDD? assume you are NOT copying over WiFi, correct?

 

[iddqd]

I copied a 12GB ISO from the hard drive to my local PC via USB, wrote at ~43MB/sec

Copying via USB from PC to File Server.

PC is connected to WiFi (10m distance, 1 wall).

NAS is connected ethernet

Regular file transfers from PC to another PC over WiFi give me about 35MB/sec.

 

[mervincm]

I would simplify.
Put the test file on your HSS to take USB and the portable media out of the picture. You did this and it copied fast so that does not appear to be a problem.

Put the notebook on the router via wire to have WiFi out of the picture.

Copy 1 large test file from the router to the NAS. assuming everything is gigabit, you will likely write at closer to 100 MB/sec. I would also copy it the other direction (after a reboot to avoid cache effects) you should see about the same performance

If not, put another PC on a wire and copy to it that.

It would also we nice to know how fast you can copy a local file on your freeNAS system to that shared volume location.

 

[azazel1024]

Remove wifi from the equation. Simplify and expand. I would suspect poor wifi performance here. Its amazing how bad wifi can be, even if you don't think the range is significant.

 

[stevech]

Also, FreeNAS writing to CIFS format is notoriously slow.

 

[Terry Kennedy]

Also, FreeNAS writing to CIFS format is notoriously slow.

I haven't looked at FreeNAS in ages, but I suspect it is using ZFS for its underlying filesystem and SAMBA for exporting CIFS shares.

There are some issues with SAMBA (or NFS) exports of ZFS filesystems, where writes are converted to synchronous. This forces a full flush to ZFS after each operation. On a command-line system, I'd use the SSD to act as a ZIL device which addresses this. Other options are to force all writes to the pool to be async in the ZFS properties (generally a bad idea).

I would expect this to be a common question in the FreeNAS forums - you might get better tuning advice there.

On my FreeBSD-based (not FreeNAS) RAIDzilla II's I get > 500MByte/sec writes (via 10GbE, of course).