Hi,
I finally took the time to create a new thread about this issue. I apologies for the threads I resurrected in the past 😇
As mentioned in the title I've got some poor disk speed using mounted share within my Linux VM (Ubuntu 18.04.3). I did few tests I'd like to share with you. Hopefully someone will be able to help me.
My VM is on the cache disk and my user share is on my data disk using cache mode : 'YES'.
Here are some stats gathered from unRaid using SSH :
Cache Drive :
Disk Drive :
Here are the stats from the VM (living on cache disk) :
While the speed decreased by +/-19% I believe it's normal due to the fact it's a VM.
Now let's mount the user share using cache mode : 'YES'.
Using NFS : (/etc/fstab : 192.168.0.54:/mnt/user/work /mnt/work nfs auto 0 0)
Using CIFS : (/etc/fstab : //192.168.0.54/work /mnt/work cifs auto,guest,uid=user,gid=user,vers=3.0,mfsymlinks 0 0)
Using p9 : (/etc/fstab : work /mnt/work 9p trans=virtio,version=9p2000.L,_netdev,rw 0 0 -- path in VM xml file : /mnt/user/work)
Using sshfs : (/etc/fstab : fuse IdentityFile=/home/user/.ssh/id_rsa,uid=user,gid=user,users,idmap=user,noatime,allow_other,_netdev,reconnect,exec,rw 0 0)
As you can see those stats are quite poor compared to the one from unRaid directly. My knowledges regarding VM's performances are quite limited but here are the assumption I had when I did those tests for the first time (even before using the user share with cache mode to 'YES') :
- I thought p9 would be the closest to 'barebone' performances but it's almost the inverse. Maybe something misconfigured ? I tried with default settings and the other options too.
- I thought sshfs would be similar to 'barebone' knowing I use a virtual bridge (br0) or would at least reach what nfs and cifs can reach.
After all those tests I don't really know what to do to improve the situation. Even if the speed with nfs/cifs is not bad ,the cut by +/- 2/3 in terms of performance seems quite big in my opinion. And before I used the cache mode to 'YES' for the user share, the cifs and nfs speed was reaching +/-20MB/s max.
The current VM is using 30 out of 32 cores and 20GB out of 32GB of RAM. I've attached the xml setting file if you'd like to have a deeper look. Same for the diagnostics file.
Thank you !
EDIT : I can confirm the same results under a Windows VM using cifs.
unraid-diagnostics-20191208-1319.zip vm-settings.txt