SOLVED Large file transfers slows SMB response time for other users

[ShimadaRiku]

• TrueNAS-12.0-U5.1
• Intel(R) Xeon(R) CPU E3-1231 v3
• 24GB memory
• Pool-1 12TBx2 mirror
• Pool-2 8TBx6 z2
• Win10 clients

User1 move/copy 500GB of data from Pool-2 to Pool-1, it transfers around 150-200MB/s which is the write performance limit of 12TB drives.

User2 tries accessing SMB network shares on Pool-2, but response times are significantly delayed by 3-5 seconds on each folder traversal. Sometimes windows explorer would unresponsive/hang even longer.

What can be done to alleviate user-2 performance woes? Is there a way to throttle/limit User1 activity?

 

[Jessep]

Increase the minimum metadata size
Do a full file system traversal to populate the metadata

 

[ShimadaRiku]

Increase the minimum metadata size
Do a full file system traversal to populate the metadata

unfamiliar with metadata, can you link me where in the documentation to configure/setup?

 

[Samuel Tai]

See this thread https://www.truenas.com/community/threads/zfs-arc-doesnt-seem-that-smart.100423/ for more details. For the TL;DR version, set a SYSCTL tunable under System->Tunables with variable vfs.zfs.arc.meta_min and value 4294967296 (4 GiB).

 

[ShimadaRiku]

Thanks! This worked.

Didn't have this issue with Freenas 9.x and been struggling since updating to Truenas 12.x.

update: this only helps initially but not entirely fix performance issue. Found the true culprit, VMware VMXNET3, stopped using it and everything is better. https://kb.vmware.com/s/article/2039495