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 starting to lean towards this being an I/O issue but I haven’t figure out what or why yet. I don’t often make changes to this environment since it’s running my Opnsens router.

    root@proxmox-02:~# zpool status
      pool: rpool
     state: ONLINE
    status: Some supported and requested features are not enabled on the pool.
            The pool can still be used, but some features are unavailable.
    action: Enable all features using 'zpool upgrade'. Once this is done,
            the pool may no longer be accessible by software that does not support
            the features. See zpool-features(7) for details.
      scan: scrub repaired 0B in 00:56:10 with 0 errors on Sun Apr 28 17:24:59 2024
    config:
    
            NAME                                    STATE     READ WRITE CKSUM
            rpool                                   ONLINE       0     0     0
              ata-ST500LM021-1KJ152_W62HRJ1A-part3  ONLINE       0     0     0
    
    errors: No known data errors
    
    • Pyrosis@lemmy.world
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      6 months ago

      It looks like you could also do a zpool upgrade. This will just upgrade your legacy pools to the newer zfs version. That command is fairly simple to run from terminal if you are already examining the pool.

      Edit

      Btw if you have ran pve updates it may be expecting some newer zfs flags for your pool. A pool upgrade may resolve the issue enabling the new features.

        • Pyrosis@lemmy.world
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          6 months ago

          Upgrading a ZFS pool itself shouldn’t make a system unbootable even if an rpool (root pool) exists on it.

          That could only happen if the upgrade took a shit during a power outage or something like that. The upgrade itself usually only takes a few seconds from the command line.

          If it makes you feel better I upgraded mine with an rpool on it and it was painless. I do have a everything backed up tho so I rarely worry. However ai understand being hesitant.

          • 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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              6 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.