HDD speed gradually slowing down

[Steven McKenzie]

I have ugpraded to 8.2 with the latest ZFS running 5x Hitachi 3TB 5K3000.

What i am finding is when i copy files using FTP or windows network, i get fast speeds around 60mb/per second then it slowly goes slower slower down to 5mb sec... I am not sure why its doing this.

Specs HP Micro server N36L
Dual 1.3ghz
8gb RAM

Thanks

 

[swissiws]

Hi There

I do have the same issue as above

System starts with around 100MB/s than gradually slows down to around 60MB/s while copy a 4GB file to either iscsi extent (device/file same issue) or CIFS - Copying a 1GB file goes with around 100MB/s or around 850Mbit/s steady.


Where are the limitations?

System:
FreeNAS 8.2p1 RAID-Z1
ML350 G5 16GB RAM
4x 2TB SATA WD Black Caviar

 

[Lalle75]

Hi folks.
I followed a discussion in the german forum with people, who have the same performance problem (like myself). It seems, that the issue is connected to the RAM FreeNAS uses to cache the ZFS drives. Yesterday a had a performance of 1 MB/sec. Today I started the NAS and got about 50 MB/sec.

The difference between the two days: 1. I restarted my whole system (router, NAS, workstation), 2. I copied some big files today and many, many, many small files yesterday.

It really feels like it is not directly connected to ZFS or UFS, but to the file cache. Maybe there is an option to clean the cache earlier.

Regards,
Lalle