virsh-storage-manage

name	virsh-storage-manage
description	Manages libvirt storage pools and LVM/ZFS volumes following create_libvirt_storage_pools.sh and vps_kvm_lvmcreate.sh patterns. Handles virsh pool-define-as, lvcreate/zfs create, pool autostart, and vz pool detection logic. Use when asked to 'create storage pool', 'add LVM volume', 'setup ZFS', or work with /dev/vz/. Do NOT use for image installation, DHCP changes, or network configuration.

virsh-storage-manage

Critical

• All storage operations target the vz pool (VG or ZFS pool). Never hardcode a different pool name unless explicitly instructed.
• Always detect thin vs. thick provisioning before lvcreate — the check is lvdisplay | grep 'Allocated pool'. Non-empty = thin pool exists.
• Always check if a pool or volume already exists before creating it (idempotency).
• Never touch scripts in unused/ — they are deprecated.
• Always export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin:/usr/X11R6/bin:/root/bin" at the top of any new shell script.

Instructions

1 — Detect pool type for the vz pool

export pool="$(virsh pool-dumpxml vz 2>/dev/null | grep '<pool' | sed s#"^.*type='\([^']*\)'.*$"#"\1"#g)"
# Returns: "logical" (LVM), "zfs", or "" (not defined)

If pool is empty, bootstrap all pools first:

/root/cpaneldirect/create_libvirt_storage_pools.sh
export pool="$(virsh pool-dumpxml vz 2>/dev/null | grep '<pool' | sed s#"^.*type='\([^']*\)'.*$"#"\1"#g)"

Verify $pool is "logical" or "zfs" before proceeding.

2 — Register a new libvirt storage pool (create_libvirt_storage_pools.sh pattern)

function vaddpool() {
  if [ "$(virsh pool-list | grep -v -e '^$' -e '^-' -e '^ Name ' | awk '{ print $1 }' | grep "$2")" = "" ]; then
    echo "Adding $1 Pool $2"
    if [ "$1" = "logical" ]; then
      virsh pool-define-as "$2" $1 --source-name "$2" --target /dev/$2
    else
      virsh pool-define-as "$2" $1 --source-name "$2"
    fi
    virsh pool-start "$2"
    virsh pool-autostart "$2"
  else
    echo "Skipping already added $1 Pool $2"
  fi
}

To register all existing ZFS pools and LVM VGs:

for i in $(zpool list -H -p 2>/dev/null | cut -d"$(echo -e "\t")" -f1); do vaddpool zfs "$i"; done
for i in $(pvdisplay -c 2>/dev/null | cut -d: -f2);                       do vaddpool logical "$i"; done

Verify with virsh pool-list --all — pool must show active and yes for autostart.

3 — Create an LVM volume in vz VG (vps_kvm_lvmcreate.sh pattern)

name=$1   # e.g. vps1337
size=$2   # size in MB, or "all"

if [ "$(lvdisplay | grep 'Allocated pool')" = "" ]; then
  thin="no"
else
  thin="yes"
fi

if [ "$size" = "all" ]; then
  lvcreate -y -L $(echo "($(pvdisplay -c | grep :vz: | cut -d: -f8,10 | tr : "*"))-(1024*1024*4)" | bc)k -n${name} vz
elif [ "$(lvdisplay /dev/vz/$name | grep "LV Size.*"$(echo "$size / 1024" | bc -l | cut -d. -f1))" = "" ]; then
  if [ "$thin" = "yes" ]; then
    lvcreate -y -V${size} -T vz/thin -n${name}
  else
    lvcreate -y -L${size} -n${name} vz
  fi
else
  echo "already exists, skipping"
fi

Verify with lvdisplay /dev/vz/${name} — must return volume info.

4 — Create a ZFS dataset in vz pool

mkdir -p /vz/${name}
zfs create vz/${name}
while [ ! -e /vz/${name} ]; do sleep 1; done

For quota-capped volumes (e.g. templates):

zfs create vz/templates
zfs set quota=100G vz/templates

Verify with zfs list vz/${name}.

5 — Resolve the block device path after creation

if [ "$pool" = "zfs" ]; then
  device="$(virsh vol-list vz --details | grep " ${name}[/ ]" | awk '{ print $2 }')"  # e.g. /vz/vps1337/os.qcow2
else
  device="/dev/vz/${name}"
fi

6 — Remove a volume

if [ "$pool" = "zfs" ]; then
  virsh vol-delete --pool vz ${name}/os.qcow2 2>/dev/null
  virsh vol-delete --pool vz ${name}          2>/dev/null
  zfs list -t snapshot | grep "/${name}@" | cut -d" " -f1 | xargs -r -n1 zfs destroy -v
  zfs destroy vz/${name}
  [ -e /vz/${name} ] && rmdir /vz/${name}
else
  lvremove -f /dev/vz/${name}
fi

Examples

User says: "Set up a 50 GB LVM volume for vps42"

Actions taken:

1. Detect pool type: pool="logical"
2. Check thin: lvdisplay | grep 'Allocated pool' → empty → thin="no"
3. Check existence: lvdisplay /dev/vz/vps42 → empty → proceed
4. Create: lvcreate -y -L51200 -nvps42 vz
5. Confirm device: device="/dev/vz/vps42"

Result: /dev/vz/vps42 exists, 50 GB thick LVM volume in vz VG.

---

User says: "Bootstrap libvirt pools on a fresh KVM host"

Actions taken:

1. Run ./create_libvirt_storage_pools.sh
2. Script calls vaddpool logical vz and/or vaddpool zfs vz depending on host config
3. virsh pool-autostart vz is called inside vaddpool

Result: virsh pool-list --all shows vz as active with autostart.

Common Issues

• virsh pool-define-as fails with "storage pool already exists": Pool is defined but stopped. Run virsh pool-start vz then virsh pool-autostart vz. Do not redefine.
• lvcreate fails with "Volume group "vz" not found": The vz VG was not created. Verify with vgs; if missing, check that physical volumes are initialized with pvcreate and VG created with vgcreate vz /dev/sdX.
• lvcreate fails with "Insufficient free space": Use vgdisplay vz to check free extents. For thin pools, check lvdisplay vz/thin pool data%.
• zfs create fails with "no such pool": Run zpool import vz or verify with zpool status. If pool is degraded, do not proceed without user confirmation.
• pool variable is empty after pool-dumpxml: vz pool not registered. Run ./create_libvirt_storage_pools.sh (located at /root/cpaneldirect/create_libvirt_storage_pools.sh on hosts) then re-check.
• Thin lvcreate fails with "pool vz/thin not found": Host has LVM but no thin pool configured. Set thin="no" and use thick provisioning: lvcreate -y -L${size} -n${name} vz.