Is the performance of this host ok or bad?

[larsen]

Hello,

I think we have a problem with the disk performance of our Proxmox 7.0 server as a "Windows Server 2012 R2" guest feels sluggish and I guess the values from pveperf should be better.

pveperf with running VM (just one on this node):

CPU BOGOMIPS:      128001.60
REGEX/SECOND:      1620077
HD SIZE:           93.99 GB (/dev/mapper/pve-root)
BUFFERED READS:    43.80 MB/sec
AVERAGE SEEK TIME: 17.86 ms
FSYNCS/SECOND:     111.22

pveperf when VM is stopped:

CPU BOGOMIPS:      128001.60
REGEX/SECOND:      1580131
HD SIZE:           93.99 GB (/dev/mapper/pve-root)
BUFFERED READS:    207.32 MB/sec
AVERAGE SEEK TIME: 7.00 ms
FSYNCS/SECOND:     234.27

Hardware:

Dell PowerEdge C6100 XS23-TY3
Intel Dual Xeon X5650, 2,67 GHz
48 GB RAM
LSI MegaRAID SAS 9260-8i
3x Seagate Exos 7E8 (ST4000NM0025), 4 TB, SAS 12 Gb/s, 7200 rpm, RAID 5

RAID Controller:

RAID 5
Strip Size: 64 kb
Access Policy: RW
Read Policy: Ahead
Write Policy: Write Through
IO Policy: Cached
DriveCache: Enable
Disable BGI: No
Link Speed: 6 gb/s

WriteCache disabled as the battery is said to be not ok.

Relevant output from "fdisk -l":

Disk /dev/sda: 7.28 TiB, 8000450330624 bytes, 15625879552 sectors
Disk model: MR9260-8i
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 19213B8D-554C-450A-A40D-85636AE09F0F

Device       Start         End     Sectors  Size Type
/dev/sda1       34        2047        2014 1007K BIOS boot
/dev/sda2     2048     1050623     1048576  512M EFI System
/dev/sda3  1050624 15625879518 15624828895  7.3T Linux LVM

Partition 1 does not start on physical sector boundary.

Guest config "/etc/pve/qemu-server/109.conf":

agent: 1
balloon: 0
boot: order=scsi0
cores: 2
cpu: host
ide2: none,media=cdrom
machine: pc-i440fx-5.2
memory: 16384
name: sql01
net0: virtio=86:F3:36:BB:03:A7,bridge=vmbr0
numa: 0
onboot: 1
ostype: win8
scsi0: lvmthin:vm-109-disk-0,discard=on,size=1000G
scsihw: virtio-scsi-pci
smbios1: uuid=6edaedd2-be73-4516-bd1c-da3d3c64fbd5
sockets: 1
tablet: 1
vga: virtio
vmgenid: 3092c762-ddd8-4ac1-9fd1-3e35d7fe5da6

 

[Dunuin]

Performance looks like what I would expect. You use raid5 so you basically only get the performance of a single drive for IOPS and IOPS are is the biggest problem using HDDs as a VM storage. And using a Raid Controller without BBU doesn't make it better because your SQLs sync writes cant be cached. You named your VM sql01 so I guess that sync writes and IOPS should be your biggest problem.

 

[larsen]

Thank you. I'm thinking of using a SAN with 10 gbit/s iSCSI instead. Do you have any experience with that?