IO Delay

X

xadox

Well-Known Member
Aug 21, 2019
63
8
48
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?
 
Last edited:
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.
 
Last edited:
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
Click to expand...

The LXC itself is running from the NVME.
 
Last edited:
Have to check. I do not remember what brand I put in. :D 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.
 
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?
 
xadox said:
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?
Click to expand...
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.
 
You must log in or register to reply here.
Top Bottom