Xeon 16GB Fsync low...

[Proxok]

Hi everyone, Anyone know why my server has a Fsync so low (85)?
- CPU (s) 6 x Intel (R) Xeon (R) CPU E5-2603 v3 @ 1.60GHz (1 Socket)
- 16GB of RAM
- Proxmox 4.4
- Linux 4.4.49-1-pve # 1 SMP PVE 4.4.49-86
- 2x ST1000DM003 on mirror Ext4
- 2x WD1003FBYZ on mirror ZFS
- 2 VMs Win2k3

~# pveperf
CPU BOGOMIPS: 19199.70
REGEX/SECOND: 1166573
HD SIZE: 890.46 GB (rpool/ROOT/pve-1)
FSYNCS/SECOND: 67.58

# zpool status
pool: rpool
state: ONLINE
scan: none requested
config:

NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
sda2 ONLINE 0 0 0
sdb2 ONLINE 0 0 0

errors: No known data errors

pool: storage
state: ONLINE
scan: none requested
config:

NAME STATE READ WRITE CKSUM
storage ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
sdc ONLINE 0 0 0
sdd ONLINE 0 0 0


# pveperf /rpool
CPU BOGOMIPS: 19199.70
REGEX/SECOND: 1252896
HD SIZE: 693.43 GB (rpool)
FSYNCS/SECOND: 89.24
DNS EXT: 41.57 ms
DNS INT: 41.18 ms
# pveperf /storage
CPU BOGOMIPS: 19199.70
REGEX/SECOND: 1252128
HD SIZE: 899.00 GB (storage)
FSYNCS/SECOND: 39.16
DNS EXT: 34.53 ms


Thanks

 

[tom]

your disks are slow. if you use cheapest desktop class SATA disks, you get what you paid for.

if you want to speed up your ZFS mirror fsync/performance, add a very fast enterprise class SSD and use it as cache (ZFS log) device.