IO Delay

[xadox]

I have always had the problem with repeatedly occurring IO delay increases up to 60% and more during heavy hard disk activity.
One of my LXCs is an SMB server and when I move large data back and forth over a long period of time, the problem usually occurs.

My specs are as follows:

• 12 x AMD Ryzen 5 2600 Six-Core Processor
• 64GB ECC RAM
• OS on NVME
• LXCs on NVME
• Virtual Environment 8.2.4
• 8x 3.5 HDD on Dell Perc/ LSI SAS2008 in JBOD
• 2x RAIDZ1 20TB (4 discs) and 8TB (4 discs)

Do you have any suggestions for me as to where I might start?

 

[leesteken]

RAIDz1 has poor IOPS and is not very suitable for running guests on, which has been discussed several times before on this forum. Use enterprise SSDs in a stripes of mirrors (like RADI10) for better performance.

EDIT: Hardware RAID5 is also faster (but less features and checksums) than RAIDz1.

EDIT2: I got confused by the NVMe, but it does not seem to matter and I deleted my confused replies.

 

[xadox]

I know, and because of that I think I read in the past that it would make more sense to use the zpool via MP.
Like in my case:

arch: amd64
cores: 4
hostname: smb
memory: 2048
mp0: /tank1/share,mp=/data
mp1: /tank1/backup,mp=/backup

The LXC itself is running from the NVME.

 

[xadox]

Have to check. I do not remember what brand I put in. It has been in use for more or less 7 years.
But why does that matter? The pure LXC runs from the NVME and the IO load is on the RAIDZ1.

 

[xadox]

As I don't want to simply throw my setup overboard for cost reasons, I'm wondering what alternatives there are.
Can an ARC cache possibly bring improvements?

 

[leesteken]

As I don't want to simply throw my setup overboard for cost reasons, I'm wondering what alternatives there are.
Can an ARC cache possibly bring improvements?

Change the RAIDz1 to a stripe of two mirrors (a in RAID10, which I suggested in my first reply)? RAIDz1 has a lot of padding (as also discussed before on this forum), so you might not even lose much space. Or use your hardware RAID controller instead of ZFS.