Low Disk Performance in VM

NeonGod

New Member
Apr 19, 2018
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Hi :) I'm new to Proxmox..

I got an old HP DL160 Server with 2x E5640 Cpu's, 24GB ECC DDR3 Ram, HP P800 Raid Controller with 512MB BBWC and 7x Kingston 120GB SSD's in Raid 0

i run: proxmox-ve: 5.1-42 (running kernel: 4.13.16-2-pve) (updated today)

pveperf:
CPU BOGOMIPS: 85339.36
REGEX/SECOND: 1500806
HD SIZE: 14.70 GB (/dev/mapper/pve-root)
BUFFERED READS: 420.67 MB/sec
AVERAGE SEEK TIME: 0.38 ms
FSYNCS/SECOND: 2255.56
DNS EXT: 33.00 ms
DNS INT: 32.69 ms

I run a VM with ubuntuserver 16.04.4 LTS and my cache is set to writeback and im using VirtIO SCSI as Controller.. i run on encrypted LVM ext4

problem is that when i copy internally i get like ~10MB/s should be higher i think ??

any help is deeply appreciated
 
no real idea, but some thought's:

-> the HP P800 is some oldish 3 GBit SAS -> maybe not very well fitted for SSD's

-> A Raid 0 should be fast, but do you really want to live with the risk?
if one of your ssd's goes bad, you will loose anything

-> Better try to get a cheap SAS HBA (maybe from Ebay) with at least 6 Gbit/s SAS
Make a mirrored Zpool out of your SSD's

-> One more thought: Were the SSD's already longer in use? Some older SSD's will bog down write rate when they wear out ( we had that with some older SSD's after some years )
 
Yeah i know it's an old SAS 3Gbit controller and it only run Sata at 150MB/s.. but still it should deliver more than 10MB/s.. Raid 0.. well it's a Mediaserver running Rclone to a Unlimited G-Drive where all data is stored.. so not a problem if i loose a disk.. got backup of VM and all data is on G-Drive.. yeah it's older Kingston v300 low-end consumer SSD's but they are fast enough to saturate the controller.. if i run same config without proxmox i get 300+ MB/s in copy's.. so i guess it got something to do with my proxmox setup.. :) I soon go get a new SSD for my desktop so i can put my old Intel 750 PCI-E NVME SSD in the server.. then problem should be solved.. :) but would like to get this to work :)

Thanks for your input though :)
 
I get the same about 10MB/s write speed a Windows VM. It may have to do with sync writes. I dont have a test server to test putting a SLOG SSD drive to see if it improves performance or disable sync writes entirely.