freenas panic: vm_page_free: freeing busy page

[calabus]

I am receiving the above panic error on my system while downloading a torrent at about 1-1.5MB a sec. My setup is a Windows 7 64 bit machine running uTorrent which points to my freenas share as its storage. I can move large files from my windows box to storage with no issues. This includes thousands of small files or several large (50-60GB). I seem to only receive the panic in the uTorrent situation. The difference in the two situations is I am simultaneously reading and writing with uTorrent as apposed to simply writing when moving files off my Windows machine. Here is my setup:

All new hardware
FreeNAS 8.3 x64
8GB RAM
6 2TB drives in three 2 drive pairs as one volume (ZFS) (CIFS share)
SUPERMICRO AOC-USAS2-L8i PCI Express SATA / SAS Eight-Port Internal RAID Adapter

When I built the system I ran auto-tune before moving any data to the drives. I had no issues moving files but running uTorrent would panic. I re-installed FreeNAS and did not tune. The same issues occurs. I tried editing loader.conf with the following, but still have the panic issue.

vm.kmem_size="1536M"
vm.kmem_size_max="2048M"
vfs.zfs.arc_min="256M"
vfs.zfs.arc_max="1024M"
#vfs.zfs.prefetch_disable="1"
#vfs.zfs.zil_disable="0"
vfs.zfs.txg.timeout="30"
vfs.zfs.vdev.max_pending="35"
vfs.zfs.vdev.min_pending="4"
vfs.zfs.txg.write_limit_override=1073741824

I'm not a *nix guy but can muddle through vi if forced. Any ideas on fixing this issue?

Just for the heck of it I ran autotune again with the settings below and same issue

sysctl:
net.inet.tcp.sendbuf_max 2097152 Generated by autotune
kern.ipc.maxsockbuf 2097152 Generated by autotune
net.inet.tcp.recvbuf_max 2097152 Generated by autotune

tuneables:
vfs.zfs.arc_max 4211862497 Generated by autotune
vm.kmem_size_max 5849809024 Generated by autotune
vm.kmem_size 4679847219 Generated by autotune

 

[cyberjock]

Well, I'm not sure that's a very wise idea to run a torrent directly off of a File Share. My guess is that you don't have enough RAM and the write cache fills to capacity while trying to keep up with the random writes. ZFS is copy-on-write, and that can heavily fragment files that are being written to in lots of very small pieces. Not to mention how much worse it would be if you were running a torrent where those writes are completely random.

I'd say that there is a big difference between copying 1000s of small files and running a bit torrent to the file system. The way in which a file system handles 1000s of small files is different to how it handles a single file that has writes coming in all over the place.

 

[calabus]

Sounds like a reasonable explanation. My only question is why does the Transmission torrent plugin exist? I would think this issue would be pretty common when using it or does it handle the reading and writing of data differently since it resides on the same system as the storage?

 

[cyberjock]

Well, for one you wouldn't have to worry about CIFS/NFS for torrents.

 

[bollar]

Have you considered upgrading to 8.3, the current version?

 

[calabus]

Sorry for the typo....I am indeed running 8.3

 

[cyberjock]

I figured it had to be a typo since autotune didn't exist until 8.2. Just forgot to ask about it. :P

There's also no guarantee that Transmission doesn't have stuff optimized for copy-on-write file systems. Copy-on-Write is virtually nonexistent on the Windows platform.

 

[calabus]

I went ahead and setup Transmission and I'm Currently testing a 4GB download. So far no issues. Although I think I have my mount points all screwed since the download doesn't seem to be in the folder it should be in. I'll figure that out at some point. Just glad it is working for now. As for my tuning above....does that look right for my setup? Any suggestions?

Thanks for the info and advice!

 

[paleoN]

As for my tuning above....does that look right for my setup?

What's in the top of the first post? It looks wrong for 8.3. Several of those values are going the wrong way.

For 8.3 I would try only setting vfs.zfs.arc_max with a value of 5120M/4096M and keep the network sysctls.

 

[calabus]

What's in the top of the first post? It looks wrong for 8.3. Several of those values are going the wrong way.

For 8.3 I would try only setting vfs.zfs.arc_max with a value of 5120M/4096M and keep the network sysctls.

The top of the post was my previous tuning. My current tuning was near the bottom...which is:

Just for the heck of it I ran autotune again with the settings below and same issue

sysctl:
net.inet.tcp.sendbuf_max 2097152 Generated by autotune
kern.ipc.maxsockbuf 2097152 Generated by autotune
net.inet.tcp.recvbuf_max 2097152 Generated by autotune

tuneables:
vfs.zfs.arc_max 4211862497 Generated by autotune
vm.kmem_size_max 5849809024 Generated by autotune
vm.kmem_size 4679847219 Generated by autotune