Hi,
My HW:
HP ML310e v8
32GB RAM
2xWD MX500 500GB SATA (Mirrored / Compressed / GELI encrypted)
2xWD Red 12TB (Mirrored / Compressed)
TrueNAS-12.0-RC1
recordsize=128k
ashift=12
I have a pool configured with the 2 x WD Red drives mirrored and another with the 2 x MX500.
Using fio to test I notice that the the uncached write speed is pretty good at around 180MB/s for each disk when writing to the pool but the uncached reads from the pool are slower at about 120MB/s. If I look at gstat the disks are almost 100% busy during the read and write operations.
Doing the same test with the MX500 pool I see a read and write speed of about 400MB/s. This is perhaps a little bit slower that what might be expected but at least the read and write throughput is the same.
Note that I get similar results if I use dd with bs=1m and of=/dev/null.
Does anyone have any ideas why the HDD pool is behaving like this (slower reads)?
Thanks,
Ian.
My HW:
HP ML310e v8
32GB RAM
2xWD MX500 500GB SATA (Mirrored / Compressed / GELI encrypted)
2xWD Red 12TB (Mirrored / Compressed)
TrueNAS-12.0-RC1
recordsize=128k
ashift=12
I have a pool configured with the 2 x WD Red drives mirrored and another with the 2 x MX500.
Using fio to test I notice that the the uncached write speed is pretty good at around 180MB/s for each disk when writing to the pool but the uncached reads from the pool are slower at about 120MB/s. If I look at gstat the disks are almost 100% busy during the read and write operations.
Doing the same test with the MX500 pool I see a read and write speed of about 400MB/s. This is perhaps a little bit slower that what might be expected but at least the read and write throughput is the same.
Note that I get similar results if I use dd with bs=1m and of=/dev/null.
Does anyone have any ideas why the HDD pool is behaving like this (slower reads)?
Thanks,
Ian.
