Proxmox Disk Performance Problems - eviltoast

I’ve started encountering a problem that I should use some assistance troubleshooting. I’ve got a Proxmox system that hosts, primarily, my Opnsense router. I’ve had this specific setup for about a year.

Recently, I’ve been experiencing sluggishness and noticed that the IO wait is through the roof. Rebooting the Opnsense VM, which normally only takes a few minutes is now taking upwards of 15-20. The entire time my IO wait sits between 50-80%.

The system has 1 disk in it that is formatted ZFS. I’ve checked dmesg, and the syslog for indications of disk errors (this feels like a failing disk) and found none. I also checked the smart statistics and they all “PASSED”.

Any pointers would be appreciated.

Example of my most recent host reboot.

Edit: I believe I’ve found the root cause of the change in performance and it was a bit of shooting myself in the foot. I’ve been experimenting with different tools for log collection and the most recent one is a SIEM tool called Wazuh. I didn’t realize that upon reboot it runs an integrity check that generates a ton of disk I/O. So when I rebooted this proxmox server, that integrity check was running on proxmox, my pihole, and (I think) opnsense concurrently. All against a single consumer grade HDD.

Thanks to everyone who responded. I really appreciate all the performance tuning guidance. I’ve also made the following changes:

  1. Added a 2nd drive (I have several of these lying around, don’t ask) converting the zfs pool into a mirror. This gives me both redundancy and should improve read performance.
  2. Configured a 2nd storage target on the same zpool with compression enabled and a 64k block size in proxmox. I then migrated the 2 VMs to that storage.
  3. Since I’m collecting logs in Wazuh I set Opnsense to use ram disks for /tmp and /var/log.

Rebooted Opensense and it was back up in 1:42 min.

  • I’m referring to this.

    … using grub to directly boot from ZFS - such setups are in general not safe to run zpool upgrade on!

    $ sudo proxmox-boot-tool status
    Re-executing '/usr/sbin/proxmox-boot-tool' in new private mount namespace..
    System currently booted with legacy bios
    8357-FBD5 is configured with: grub (versions: 6.5.11-7-pve, 6.5.13-5-pve, 6.8.4-2-pve)
    

    Unless I’m misunderstanding the guidance.

    • Pyrosis@lemmy.world
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      7 months ago

      It looks like you are using legacy bios. mine is using uefi with a zfs rpool

      proxmox-boot-tool status
      Re-executing '/usr/sbin/proxmox-boot-tool' in new private mount namespace..
      System currently booted with uefi
      31FA-87E2 is configured with: uefi (versions: 6.5.11-8-pve, 6.5.13-5-pve)
      

      However, like with everything a method always exists to get it done. Or not if you are concerned.

      If you are interested it would look like…

      Pool Upgrade

      sudo zpool upgrade <pool_name>
      

      Confirm Upgrade

      sudo zpool status
      
      

      Refresh boot config

      sudo pveboot-tool refresh
      
      

      Confirm Boot configuration

      cat /boot/grub/grub.cfg
      

      You are looking for directives like this to see if they are indeed pointing at your existing rpool

      root=ZFS=rpool/ROOT/pve-1 boot=zfs quiet
      

      here is my file if it helps you compare…

      #
      # DO NOT EDIT THIS FILE
      #
      # It is automatically generated by grub-mkconfig using templates
      # from /etc/grub.d and settings from /etc/default/grub
      #
      
      ### BEGIN /etc/grub.d/000_proxmox_boot_header ###
      #
      # This system is booted via proxmox-boot-tool! The grub-config used when
      # booting from the disks configured with proxmox-boot-tool resides on the vfat
      # partitions with UUIDs listed in /etc/kernel/proxmox-boot-uuids.
      # /boot/grub/grub.cfg is NOT read when booting from those disk!
      ### END /etc/grub.d/000_proxmox_boot_header ###
      
      ### BEGIN /etc/grub.d/00_header ###
      if [ -s $prefix/grubenv ]; then
        set have_grubenv=true
        load_env
      fi
      if [ "${next_entry}" ] ; then
         set default="${next_entry}"
         set next_entry=
         save_env next_entry
         set boot_once=true
      else
         set default="0"
      fi
      
      if [ x"${feature_menuentry_id}" = xy ]; then
        menuentry_id_option="--id"
      else
        menuentry_id_option=""
      fi
      
      export menuentry_id_option
      
      if [ "${prev_saved_entry}" ]; then
        set saved_entry="${prev_saved_entry}"
        save_env saved_entry
        set prev_saved_entry=
        save_env prev_saved_entry
        set boot_once=true
      fi
      
      function savedefault {
        if [ -z "${boot_once}" ]; then
          saved_entry="${chosen}"
          save_env saved_entry
        fi
      }
      function load_video {
        if [ x$feature_all_video_module = xy ]; then
          insmod all_video
        else
          insmod efi_gop
          insmod efi_uga
          insmod ieee1275_fb
          insmod vbe
          insmod vga
          insmod video_bochs
          insmod video_cirrus
        fi
      }
      
      if loadfont unicode ; then
        set gfxmode=auto
        load_video
        insmod gfxterm
        set locale_dir=$prefix/locale
        set lang=en_US
        insmod gettext
      fi
      terminal_output gfxterm
      if [ "${recordfail}" = 1 ] ; then
        set timeout=30
      else
        if [ x$feature_timeout_style = xy ] ; then
          set timeout_style=menu
          set timeout=5
        # Fallback normal timeout code in case the timeout_style feature is
        # unavailable.
        else
          set timeout=5
        fi
      fi
      ### END /etc/grub.d/00_header ###
      
      ### BEGIN /etc/grub.d/05_debian_theme ###
      set menu_color_normal=cyan/blue
      set menu_color_highlight=white/blue
      ### END /etc/grub.d/05_debian_theme ###
      
      ### BEGIN /etc/grub.d/10_linux ###
      function gfxmode {
              set gfxpayload="${1}"
      }
      set linux_gfx_mode=
      export linux_gfx_mode
      menuentry 'Proxmox VE GNU/Linux' --class proxmox --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-/dev/sdc3' {
              load_video
              insmod gzio
              if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
              insmod part_gpt
              echo    'Loading Linux 6.5.13-5-pve ...'
              linux   /ROOT/pve-1@/boot/vmlinuz-6.5.13-5-pve root=ZFS=/ROOT/pve-1 ro       root=ZFS=rpool/ROOT/pve-1 boot=zfs quiet
              echo    'Loading initial ramdisk ...'
              initrd  /ROOT/pve-1@/boot/initrd.img-6.5.13-5-pve
      }
      submenu 'Advanced options for Proxmox VE GNU/Linux' $menuentry_id_option 'gnulinux-advanced-/dev/sdc3' {
              menuentry 'Proxmox VE GNU/Linux, with Linux 6.5.13-5-pve' --class proxmox --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.5.13-5-pve-advanced-/dev/sdc3' {
                      load_video
                      insmod gzio
                      if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
                      insmod part_gpt
                      echo    'Loading Linux 6.5.13-5-pve ...'
                      linux   /ROOT/pve-1@/boot/vmlinuz-6.5.13-5-pve root=ZFS=/ROOT/pve-1 ro       root=ZFS=rpool/ROOT/pve-1 boot=zfs quiet
                      echo    'Loading initial ramdisk ...'
                      initrd  /ROOT/pve-1@/boot/initrd.img-6.5.13-5-pve
              }
              menuentry 'Proxmox VE GNU/Linux, with Linux 6.5.13-5-pve (recovery mode)' --class proxmox --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.5.13-5-pve-recovery-/dev/sdc3' {
                      load_video
                      insmod gzio
                      if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
                      insmod part_gpt
                      echo    'Loading Linux 6.5.13-5-pve ...'
                      linux   /ROOT/pve-1@/boot/vmlinuz-6.5.13-5-pve root=ZFS=/ROOT/pve-1 ro single       root=ZFS=rpool/ROOT/pve-1 boot=zfs
                      echo    'Loading initial ramdisk ...'
                      initrd  /ROOT/pve-1@/boot/initrd.img-6.5.13-5-pve
              }
              menuentry 'Proxmox VE GNU/Linux, with Linux 6.5.11-8-pve' --class proxmox --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.5.11-8-pve-advanced-/dev/sdc3' {
                      load_video
                      insmod gzio
                      if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
                      insmod part_gpt
                      echo    'Loading Linux 6.5.11-8-pve ...'
                      linux   /ROOT/pve-1@/boot/vmlinuz-6.5.11-8-pve root=ZFS=/ROOT/pve-1 ro       root=ZFS=rpool/ROOT/pve-1 boot=zfs quiet
                      echo    'Loading initial ramdisk ...'
                      initrd  /ROOT/pve-1@/boot/initrd.img-6.5.11-8-pve
              }
              menuentry 'Proxmox VE GNU/Linux, with Linux 6.5.11-8-pve (recovery mode)' --class proxmox --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.5.11-8-pve-recovery-/dev/sdc3' {
                      load_video
                      insmod gzio
                      if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
                      insmod part_gpt
                      echo    'Loading Linux 6.5.11-8-pve ...'
                      linux   /ROOT/pve-1@/boot/vmlinuz-6.5.11-8-pve root=ZFS=/ROOT/pve-1 ro single       root=ZFS=rpool/ROOT/pve-1 boot=zfs
                      echo    'Loading initial ramdisk ...'
                      initrd  /ROOT/pve-1@/boot/initrd.img-6.5.11-8-pve
              }
      }
      
      ### END /etc/grub.d/10_linux ###
      
      ### BEGIN /etc/grub.d/20_linux_xen ###
      
      ### END /etc/grub.d/20_linux_xen ###
      
      ### BEGIN /etc/grub.d/20_memtest86+ ###
      ### END /etc/grub.d/20_memtest86+ ###
      
      ### BEGIN /etc/grub.d/30_os-prober ###
      ### END /etc/grub.d/30_os-prober ###
      
      ### BEGIN /etc/grub.d/30_uefi-firmware ###
      menuentry 'UEFI Firmware Settings' $menuentry_id_option 'uefi-firmware' {
              fwsetup
      }
      ### END /etc/grub.d/30_uefi-firmware ###
      
      ### BEGIN /etc/grub.d/40_custom ###
      # This file provides an easy way to add custom menu entries.  Simply type the
      # menu entries you want to add after this comment.  Be careful not to change
      # the 'exec tail' line above.
      ### END /etc/grub.d/40_custom ###
      
      ### BEGIN /etc/grub.d/41_custom ###
      if [ -f  ${config_directory}/custom.cfg ]; then
        source ${config_directory}/custom.cfg
      elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
        source $prefix/custom.cfg
      fi
      ### END /etc/grub.d/41_custom ###
      

      You can see the lines by the linux sections.