Useful file system for UCS5 on Proxmox


I chose a UCS environment on Proxmox for my project work. So far, I have always created the partition layout in UCS (guest) as follows:

/dev/sda1		ext4	100GB		/           noatime nodiratime
/dev/sda2		XFS 	100GB		/var
/dev/sda3		XFS 	100GB		/home       rw,noatime,nodiratime,attr2,inode64,noquota    0       0
/data/sdb1      XFS     XXX         /data01     rw,noatime,nodiratime,attr2,inode64,noquota    0       0

The storage pool on the PVE is an HBA with 4 x 4TB SSDs as ZFS (RAID5).

I would like to configure the system in the VM for maximum throughput. Is the layout OK or is there room for improvement?

with best

Since XFS is optimal for larger data, I formatted /, /var and /home with ext4 and /data01 with XFS. I now have the following layout:

UUID=57c2a85c-1c9c-4d91-9ebd-7e1c3e71cd33       /       ext4    discard,noatime,nodiratime,errors=remount-ro    0       1
UUID=42c1c555-27ac-4d83-86c4-1d86da69dd4d       /data01 xfs     noatime,relatime        0       0
UUID=a09b399b-4b5d-4746-b6e2-bd1cf06a0e75       /home   ext4    discard,noatime,nodiratime      0       2
UUID=a5a815d7-3551-498d-b3d3-a69a6e528931       /var    ext4    discard,noatime,nodiratime      0       2

My tests in the UCS-VM showed:

root@srv01:~# dd if=/dev/zero of=/root/testfile bs=512K count=1000 oflag=direct
1000+0 Datensätze ein
1000+0 Datensätze aus
524288000 bytes (524 MB, 500 MiB) copied, 0,381033 s, 1,4 GB/s
root@srv01:~# dd if=/dev/zero of=/root/testfile bs=4096 count=10000 oflag=direct
10000+0 Datensätze ein
10000+0 Datensätze aus
40960000 bytes (41 MB, 39 MiB) copied, 0,424101 s, 96,6 MB/s
root@srv01:~# dd if=/dev/zero of=/data01/testfile bs=1G count=100 oflag=direct
100+0 Datensätze ein
100+0 Datensätze aus
107374182400 bytes (107 GB, 100 GiB) copied, 135,032 s, 795 MB/s
root@srv01:~# dd if=/dev/zero of=/data01/testfile bs=30M count=100 oflag=direct
100+0 Datensätze ein
100+0 Datensätze aus
3145728000 bytes (3,1 GB, 2,9 GiB) copied, 1,65142 s, 1,9 GB/s

I think that’s ok? or should I use other options with dd?


what is your goal you want to achieve? If you want to test the HDD/SSD, its better to have a look at hdparm or bonnie++.


I would like to test how much data throughput I lose from the pre-virtualization host (PVE) to the VM (UCS) or optimize this as far as possible :slight_smile:

Thanks, I will have a look and test it.