Thomymaster
Contributor
- Joined
- Apr 26, 2013
- Messages
- 142
Hi
Yesterday i installed my mirrored SSDs (ADATA SX900 64GB) to enably "sync=always" in my ZFS dataset which is used to provide and ESXi datastore.
Before this, i could get approx. 100MB/s with CrystalDiskMark on a VM, but now i am stuck to a maximum of 25MB/s. The command "gstat" showed me the same. The SSDs are connected to the onboard S-ATA2 controller.
I have 16GB of RAM and 4 1.5TB drives in a striped-mirror config running the latest FreeNAS. Further i have enabled these kernel tune values:
vm.kmem_size 14336M
vfs.zfs.arc_max 12288M
vfs.zfs.arc_min 12288M
vfs.zfs.prefetch_disable 0
vfs.zfs.zil_disable 0
vfs.zfs.txg.timeout 5
vfs.zfs.vdev.max_pending 10
vfs.zfs.vdev.min_pending 4
vfs.zfs.write_limit_override 0
What causes this issue?
i created the mirror using
zdb shows ashift=9 for the 2 SSD devices. Could it be that i have to create a partition and align it to use 4K sectors?
If so, how do i do that?
Best,
Thomas
Yesterday i installed my mirrored SSDs (ADATA SX900 64GB) to enably "sync=always" in my ZFS dataset which is used to provide and ESXi datastore.
Before this, i could get approx. 100MB/s with CrystalDiskMark on a VM, but now i am stuck to a maximum of 25MB/s. The command "gstat" showed me the same. The SSDs are connected to the onboard S-ATA2 controller.
I have 16GB of RAM and 4 1.5TB drives in a striped-mirror config running the latest FreeNAS. Further i have enabled these kernel tune values:
vm.kmem_size 14336M
vfs.zfs.arc_max 12288M
vfs.zfs.arc_min 12288M
vfs.zfs.prefetch_disable 0
vfs.zfs.zil_disable 0
vfs.zfs.txg.timeout 5
vfs.zfs.vdev.max_pending 10
vfs.zfs.vdev.min_pending 4
vfs.zfs.write_limit_override 0
What causes this issue?
i created the mirror using
Code:
zpool add zpool1 log ada4 ada5
zdb shows ashift=9 for the 2 SSD devices. Could it be that i have to create a partition and align it to use 4K sectors?
If so, how do i do that?
Best,
Thomas