rbd: implement GetMirrorSource in manager

implementing GetMirrorSource in manager
to return volume or the volumegroup based
on the replication source, if replication
source is nil return the volume details
for backward compatibility.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
This commit is contained in:
Madhu Rajanna 2024-11-19 11:26:00 +01:00
parent 7cf5974e73
commit 8ee57e0bb7
6 changed files with 228 additions and 155 deletions

View File

@ -257,9 +257,9 @@ func validateSchedulingInterval(interval string) error {
func (rs *ReplicationServer) EnableVolumeReplication(ctx context.Context,
req *replication.EnableVolumeReplicationRequest,
) (*replication.EnableVolumeReplicationResponse, error) {
volumeID := csicommon.GetIDFromReplication(req)
if volumeID == "" {
return nil, status.Error(codes.InvalidArgument, "empty volume ID in request")
reqID := csicommon.GetIDFromReplication(req)
if reqID == "" {
return nil, status.Error(codes.InvalidArgument, "empty ID in request")
}
cr, err := util.NewUserCredentials(req.GetSecrets())
if err != nil {
@ -272,24 +272,21 @@ func (rs *ReplicationServer) EnableVolumeReplication(ctx context.Context,
return nil, err
}
if acquired := rs.VolumeLocks.TryAcquire(volumeID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, volumeID)
if acquired := rs.VolumeLocks.TryAcquire(reqID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, reqID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, volumeID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, reqID)
}
defer rs.VolumeLocks.Release(volumeID)
defer rs.VolumeLocks.Release(reqID)
mgr := rbd.NewManager(rs.csiID, req.GetParameters(), req.GetSecrets())
defer mgr.Destroy(ctx)
rbdVol, err := mgr.GetVolumeByID(ctx, volumeID)
volumes, mirror, err := mgr.GetMirrorSource(ctx, reqID, req.GetReplicationSource())
if err != nil {
return nil, getGRPCError(err)
}
mirror, err := rbdVol.ToMirror()
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
defer destoryVolumes(ctx, volumes)
// extract the mirroring mode
mirroringMode, err := getMirroringMode(ctx, req.GetParameters())
@ -309,10 +306,10 @@ func (rs *ReplicationServer) EnableVolumeReplication(ctx context.Context,
return nil, status.Error(codes.Internal, err.Error())
}
if info.GetState() != librbd.MirrorImageEnabled.String() {
for _, rbdVol := range volumes {
err = rbdVol.HandleParentImageExistence(ctx, flattenMode)
if err != nil {
log.ErrorLog(ctx, err.Error())
err = fmt.Errorf("failed to handle parent image for volume group %q: %w", mirror, err)
return nil, getGRPCError(err)
}
err = mirror.EnableMirroring(ctx, mirroringMode)
@ -322,6 +319,7 @@ func (rs *ReplicationServer) EnableVolumeReplication(ctx context.Context,
return nil, status.Error(codes.Internal, err.Error())
}
}
}
return &replication.EnableVolumeReplicationResponse{}, nil
}
@ -332,9 +330,9 @@ func (rs *ReplicationServer) EnableVolumeReplication(ctx context.Context,
func (rs *ReplicationServer) DisableVolumeReplication(ctx context.Context,
req *replication.DisableVolumeReplicationRequest,
) (*replication.DisableVolumeReplicationResponse, error) {
volumeID := csicommon.GetIDFromReplication(req)
if volumeID == "" {
return nil, status.Error(codes.InvalidArgument, "empty volume ID in request")
reqID := csicommon.GetIDFromReplication(req)
if reqID == "" {
return nil, status.Error(codes.InvalidArgument, "empty ID in request")
}
cr, err := util.NewUserCredentials(req.GetSecrets())
if err != nil {
@ -342,24 +340,21 @@ func (rs *ReplicationServer) DisableVolumeReplication(ctx context.Context,
}
defer cr.DeleteCredentials()
if acquired := rs.VolumeLocks.TryAcquire(volumeID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, volumeID)
if acquired := rs.VolumeLocks.TryAcquire(reqID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, reqID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, volumeID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, reqID)
}
defer rs.VolumeLocks.Release(volumeID)
defer rs.VolumeLocks.Release(reqID)
mgr := rbd.NewManager(rs.csiID, req.GetParameters(), req.GetSecrets())
defer mgr.Destroy(ctx)
rbdVol, err := mgr.GetVolumeByID(ctx, volumeID)
volumes, mirror, err := mgr.GetMirrorSource(ctx, reqID, req.GetReplicationSource())
if err != nil {
return nil, getGRPCError(err)
}
mirror, err := rbdVol.ToMirror()
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
defer destoryVolumes(ctx, volumes)
// extract the force option
force, err := getForceOption(ctx, req.GetParameters())
@ -378,7 +373,7 @@ func (rs *ReplicationServer) DisableVolumeReplication(ctx context.Context,
case librbd.MirrorImageDisabled.String():
// image mirroring is still disabling
case librbd.MirrorImageDisabling.String():
return nil, status.Errorf(codes.Aborted, "%s is in disabling state", volumeID)
return nil, status.Errorf(codes.Aborted, "%s is in disabling state", reqID)
case librbd.MirrorImageEnabled.String():
err = corerbd.DisableVolumeReplication(mirror, ctx, info.IsPrimary(), force)
if err != nil {
@ -400,9 +395,9 @@ func (rs *ReplicationServer) DisableVolumeReplication(ctx context.Context,
func (rs *ReplicationServer) PromoteVolume(ctx context.Context,
req *replication.PromoteVolumeRequest,
) (*replication.PromoteVolumeResponse, error) {
volumeID := csicommon.GetIDFromReplication(req)
if volumeID == "" {
return nil, status.Error(codes.InvalidArgument, "empty volume ID in request")
reqID := csicommon.GetIDFromReplication(req)
if reqID == "" {
return nil, status.Error(codes.InvalidArgument, "empty ID in request")
}
cr, err := util.NewUserCredentials(req.GetSecrets())
if err != nil {
@ -410,24 +405,21 @@ func (rs *ReplicationServer) PromoteVolume(ctx context.Context,
}
defer cr.DeleteCredentials()
if acquired := rs.VolumeLocks.TryAcquire(volumeID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, volumeID)
if acquired := rs.VolumeLocks.TryAcquire(reqID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, reqID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, volumeID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, reqID)
}
defer rs.VolumeLocks.Release(volumeID)
defer rs.VolumeLocks.Release(reqID)
mgr := rbd.NewManager(rs.csiID, req.GetParameters(), req.GetSecrets())
defer mgr.Destroy(ctx)
rbdVol, err := mgr.GetVolumeByID(ctx, volumeID)
volumes, mirror, err := mgr.GetMirrorSource(ctx, reqID, req.GetReplicationSource())
if err != nil {
return nil, getGRPCError(err)
}
mirror, err := rbdVol.ToMirror()
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
defer destoryVolumes(ctx, volumes)
info, err := mirror.GetMirroringInfo(ctx)
if err != nil {
@ -440,7 +432,7 @@ func (rs *ReplicationServer) PromoteVolume(ctx context.Context,
return nil, status.Errorf(
codes.InvalidArgument,
"mirroring is not enabled on %s, image is in %s Mode",
volumeID,
reqID,
info.GetState())
}
@ -477,10 +469,10 @@ func (rs *ReplicationServer) PromoteVolume(ctx context.Context,
}
log.DebugLog(
ctx,
"Added scheduling at interval %s, start time %s for volume %s",
"Added scheduling at interval %s, start time %s for Id %s",
interval,
startTime,
rbdVol)
reqID)
}
return &replication.PromoteVolumeResponse{}, nil
@ -493,9 +485,9 @@ func (rs *ReplicationServer) PromoteVolume(ctx context.Context,
func (rs *ReplicationServer) DemoteVolume(ctx context.Context,
req *replication.DemoteVolumeRequest,
) (*replication.DemoteVolumeResponse, error) {
volumeID := csicommon.GetIDFromReplication(req)
if volumeID == "" {
return nil, status.Error(codes.InvalidArgument, "empty volume ID in request")
reqID := csicommon.GetIDFromReplication(req)
if reqID == "" {
return nil, status.Error(codes.InvalidArgument, "empty ID in request")
}
cr, err := util.NewUserCredentials(req.GetSecrets())
if err != nil {
@ -503,31 +495,21 @@ func (rs *ReplicationServer) DemoteVolume(ctx context.Context,
}
defer cr.DeleteCredentials()
if acquired := rs.VolumeLocks.TryAcquire(volumeID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, volumeID)
if acquired := rs.VolumeLocks.TryAcquire(reqID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, reqID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, volumeID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, reqID)
}
defer rs.VolumeLocks.Release(volumeID)
defer rs.VolumeLocks.Release(reqID)
mgr := rbd.NewManager(rs.csiID, req.GetParameters(), req.GetSecrets())
defer mgr.Destroy(ctx)
rbdVol, err := mgr.GetVolumeByID(ctx, volumeID)
volumes, mirror, err := mgr.GetMirrorSource(ctx, reqID, req.GetReplicationSource())
if err != nil {
return nil, getGRPCError(err)
}
mirror, err := rbdVol.ToMirror()
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
creationTime, err := rbdVol.GetCreationTime(ctx)
if err != nil {
log.ErrorLog(ctx, err.Error())
return nil, status.Error(codes.Internal, err.Error())
}
defer destoryVolumes(ctx, volumes)
info, err := mirror.GetMirroringInfo(ctx)
if err != nil {
@ -540,24 +522,33 @@ func (rs *ReplicationServer) DemoteVolume(ctx context.Context,
return nil, status.Errorf(
codes.InvalidArgument,
"mirroring is not enabled on %s, image is in %s Mode",
volumeID,
reqID,
info.GetState())
}
// demote image to secondary
if info.IsPrimary() {
for _, vol := range volumes {
// store the image creation time for resync
_, err = rbdVol.GetMetadata(imageCreationTimeKey)
creationTime, cErr := vol.GetCreationTime(ctx)
if cErr != nil {
log.ErrorLog(ctx, cErr.Error())
return nil, status.Error(codes.Internal, cErr.Error())
}
// store the image creation time for resync
_, err = vol.GetMetadata(imageCreationTimeKey)
if err != nil && errors.Is(err, librbd.ErrNotFound) {
log.DebugLog(ctx, "setting image creation time %s for %s", creationTime, rbdVol)
err = rbdVol.SetMetadata(imageCreationTimeKey, timestampToString(creationTime))
log.DebugLog(ctx, "setting image creation time %s for %s", creationTime, vol)
err = vol.SetMetadata(imageCreationTimeKey, timestampToString(creationTime))
}
if err != nil {
log.ErrorLog(ctx, err.Error())
return nil, status.Error(codes.Internal, err.Error())
}
}
err = mirror.Demote(ctx)
if err != nil {
log.ErrorLog(ctx, err.Error())
@ -604,9 +595,9 @@ func checkRemoteSiteStatus(ctx context.Context, mirrorStatus []types.SiteStatus)
func (rs *ReplicationServer) ResyncVolume(ctx context.Context,
req *replication.ResyncVolumeRequest,
) (*replication.ResyncVolumeResponse, error) {
volumeID := csicommon.GetIDFromReplication(req)
if volumeID == "" {
return nil, status.Error(codes.InvalidArgument, "empty volume ID in request")
reqID := csicommon.GetIDFromReplication(req)
if reqID == "" {
return nil, status.Error(codes.InvalidArgument, "empty ID in request")
}
cr, err := util.NewUserCredentials(req.GetSecrets())
if err != nil {
@ -614,23 +605,20 @@ func (rs *ReplicationServer) ResyncVolume(ctx context.Context,
}
defer cr.DeleteCredentials()
if acquired := rs.VolumeLocks.TryAcquire(volumeID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, volumeID)
if acquired := rs.VolumeLocks.TryAcquire(reqID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, reqID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, volumeID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, reqID)
}
defer rs.VolumeLocks.Release(volumeID)
defer rs.VolumeLocks.Release(reqID)
mgr := rbd.NewManager(rs.csiID, req.GetParameters(), req.GetSecrets())
defer mgr.Destroy(ctx)
rbdVol, err := mgr.GetVolumeByID(ctx, volumeID)
volumes, mirror, err := mgr.GetMirrorSource(ctx, reqID, req.GetReplicationSource())
if err != nil {
return nil, getGRPCError(err)
}
mirror, err := rbdVol.ToMirror()
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
defer destoryVolumes(ctx, volumes)
info, err := mirror.GetMirroringInfo(ctx)
if err != nil {
@ -695,9 +683,10 @@ func (rs *ReplicationServer) ResyncVolume(ctx context.Context,
ready = checkRemoteSiteStatus(ctx, sts.GetAllSitesStatus())
}
creationTime, err := rbdVol.GetCreationTime(ctx)
if err != nil {
return nil, status.Errorf(codes.Internal, "failed to get image info for %s: %s", rbdVol, err.Error())
for _, vol := range volumes {
creationTime, tErr := vol.GetCreationTime(ctx)
if tErr != nil {
return nil, status.Errorf(codes.Internal, "failed to get image info for %s: %s", vol, tErr.Error())
}
// image creation time is stored in the image metadata. it looks like
@ -705,12 +694,13 @@ func (rs *ReplicationServer) ResyncVolume(ctx context.Context,
// If the image gets resynced the local image creation time will be
// lost, if the keys is not present in the image metadata then we can
// assume that the image is already resynced.
savedImageTime, err := rbdVol.GetMetadata(imageCreationTimeKey)
var savedImageTime string
savedImageTime, err = vol.GetMetadata(imageCreationTimeKey)
if err != nil && !errors.Is(err, librbd.ErrNotFound) {
return nil, status.Errorf(codes.Internal,
"failed to get %s key from image metadata for %s: %s",
imageCreationTimeKey,
rbdVol,
vol,
err.Error())
}
@ -719,12 +709,15 @@ func (rs *ReplicationServer) ResyncVolume(ctx context.Context,
if sErr != nil {
return nil, status.Errorf(codes.Internal, "failed to parse image creation time: %s", sErr.Error())
}
log.DebugLog(ctx, "image %s, savedImageTime=%v, currentImageTime=%v", rbdVol, st, creationTime)
log.DebugLog(ctx, "image %s, savedImageTime=%v, currentImageTime=%v", vol, st, creationTime)
if req.GetForce() && st.Equal(*creationTime) {
err = mirror.Resync(ctx)
if err != nil {
return nil, getGRPCError(err)
}
// Break the loop as we need to issue resync only once for the image or for the group.
break
}
}
}
@ -735,10 +728,13 @@ func (rs *ReplicationServer) ResyncVolume(ctx context.Context,
}
}
err = rbdVol.RepairResyncedImageID(ctx, ready)
// update imageID for all the volumes
for _, vol := range volumes {
err = vol.RepairResyncedImageID(ctx, ready)
if err != nil {
return nil, status.Errorf(codes.Internal, "failed to resync Image ID: %s", err.Error())
}
}
resp := &replication.ResyncVolumeResponse{
Ready: ready,
@ -812,9 +808,9 @@ func getGRPCError(err error) error {
func (rs *ReplicationServer) GetVolumeReplicationInfo(ctx context.Context,
req *replication.GetVolumeReplicationInfoRequest,
) (*replication.GetVolumeReplicationInfoResponse, error) {
volumeID := csicommon.GetIDFromReplication(req)
if volumeID == "" {
return nil, status.Error(codes.InvalidArgument, "empty volume ID in request")
reqID := csicommon.GetIDFromReplication(req)
if reqID == "" {
return nil, status.Error(codes.InvalidArgument, "empty ID in request")
}
cr, err := util.NewUserCredentials(req.GetSecrets())
if err != nil {
@ -822,32 +818,20 @@ func (rs *ReplicationServer) GetVolumeReplicationInfo(ctx context.Context,
}
defer cr.DeleteCredentials()
if acquired := rs.VolumeLocks.TryAcquire(volumeID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, volumeID)
if acquired := rs.VolumeLocks.TryAcquire(reqID); !acquired {
log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, reqID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, volumeID)
return nil, status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, reqID)
}
defer rs.VolumeLocks.Release(volumeID)
defer rs.VolumeLocks.Release(reqID)
mgr := rbd.NewManager(rs.csiID, nil, req.GetSecrets())
defer mgr.Destroy(ctx)
rbdVol, err := mgr.GetVolumeByID(ctx, volumeID)
volumes, mirror, err := mgr.GetMirrorSource(ctx, reqID, req.GetReplicationSource())
if err != nil {
switch {
case errors.Is(err, corerbd.ErrImageNotFound):
err = status.Errorf(codes.NotFound, err.Error())
case errors.Is(err, util.ErrPoolNotFound):
err = status.Errorf(codes.NotFound, err.Error())
default:
err = status.Errorf(codes.Internal, err.Error())
}
return nil, err
}
mirror, err := rbdVol.ToMirror()
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
return nil, getGRPCError(err)
}
defer destoryVolumes(ctx, volumes)
info, err := mirror.GetMirroringInfo(ctx)
if err != nil {
@ -978,3 +962,10 @@ func checkVolumeResyncStatus(ctx context.Context, localStatus types.SiteStatus)
return nil
}
// destoryVolumes destroys the volume connections.
func destoryVolumes(ctx context.Context, volumes []types.Volume) {
for _, vol := range volumes {
vol.Destroy(ctx)
}
}

View File

@ -88,11 +88,7 @@ func (vs *VolumeGroupServer) CreateVolumeGroup(
// resolve all volumes
volumes := make([]types.Volume, len(req.GetVolumeIds()))
defer func() {
for _, vol := range volumes {
vol.Destroy(ctx)
}
}()
defer destoryVolumes(ctx, volumes)
for i, id := range req.GetVolumeIds() {
vol, err := mgr.GetVolumeByID(ctx, id)
if err != nil {
@ -348,11 +344,7 @@ func (vs *VolumeGroupServer) ModifyVolumeGroupMembership(
// resolve all volumes
volumes := make([]types.Volume, len(toAdd))
defer func() {
for _, vol := range volumes {
vol.Destroy(ctx)
}
}()
defer destoryVolumes(ctx, volumes)
for i, id := range toAdd {
var vol types.Volume
vol, err = mgr.GetVolumeByID(ctx, id)

View File

@ -411,3 +411,7 @@ func (vg *volumeGroup) CreateSnapshots(
return snapshots, nil
}
func (vg *volumeGroup) ToMirror() (types.Mirror, error) {
return volumeGroupMirror{vg}, nil
}

View File

@ -21,6 +21,8 @@ import (
"errors"
"fmt"
"github.com/csi-addons/spec/lib/go/replication"
"github.com/ceph/ceph-csi/internal/journal"
rbd_group "github.com/ceph/ceph-csi/internal/rbd/group"
"github.com/ceph/ceph-csi/internal/rbd/types"
@ -503,3 +505,78 @@ func (mgr *rbdManager) CreateVolumeGroupSnapshot(
return vgs, nil
}
func (mgr *rbdManager) GetMirrorSource(ctx context.Context, reqID string,
rep *replication.ReplicationSource,
) ([]types.Volume, types.Mirror, error) {
switch {
// Backward compatibility: if rep is nil, we assume that the sidecar is still old and
// setting only volumeId not the replication source.
case rep == nil || rep.GetVolume() != nil:
rbdVol, err := mgr.GetVolumeByID(ctx, reqID)
if err != nil {
return nil, nil, fmt.Errorf("failed to get volume by id %q: %w", reqID, err)
}
defer func() {
if err != nil {
rbdVol.Destroy(ctx)
}
}()
var mir types.Mirror
mir, err = rbdVol.ToMirror()
if err != nil {
return nil, nil, fmt.Errorf("failed to convert volume %s to mirror: %w", rbdVol, err)
}
return []types.Volume{rbdVol}, mir, nil
case rep.GetVolumegroup() != nil:
rbdGroup, err := mgr.GetVolumeGroupByID(ctx, reqID)
if err != nil {
return nil, nil, fmt.Errorf("failed to get volume group by id %q: %w", reqID, err)
}
defer func() {
if err != nil {
rbdGroup.Destroy(ctx)
}
}()
var mir types.Mirror
mir, err = rbdGroup.ToMirror()
if err != nil {
return nil, nil, fmt.Errorf("failed to convert volume group %s to mirror: %w", rbdGroup, err)
}
var vols []types.Volume
vols, err = rbdGroup.ListVolumes(ctx)
if err != nil {
return nil, nil, fmt.Errorf("failed to list volumes in volume group %q: %w", rbdGroup, err)
}
// Get all the volume with connection and return it
volumes := make([]types.Volume, len(vols))
// Destroy connections if there is any error
defer func() {
if err != nil {
for _, vol := range vols {
vol.Destroy(ctx)
}
}
}()
for i, vol := range vols {
var id string
id, err = vol.GetID(ctx)
if err != nil {
return nil, nil, fmt.Errorf("failed to get id for volume %q in group %q: %w", vol, rbdGroup, err)
}
var v types.Volume
v, err = mgr.GetVolumeByID(ctx, id)
if err != nil {
return nil, nil, fmt.Errorf("failed to get volume by id %q in group %q: %w", id, rbdGroup, err)
}
volumes[i] = v
}
return volumes, mir, nil
default:
return nil, nil, errors.New("replication source is not set")
}
}

View File

@ -73,4 +73,7 @@ type VolumeGroup interface {
// The Snapshots are crash consistent, and created as a consistency
// group.
CreateSnapshots(ctx context.Context, cr *util.Credentials, name string) ([]Snapshot, error)
// ToMirror converts the VolumeGroup to a Mirror.
ToMirror() (Mirror, error)
}

View File

@ -18,6 +18,8 @@ package types
import (
"context"
"github.com/csi-addons/spec/lib/go/replication"
)
// VolumeResolver can be used to construct a Volume from a CSI VolumeId.
@ -67,4 +69,8 @@ type Manager interface {
// VolumeGroup was paused, the snapshots in the group are crash
// consistent.
CreateVolumeGroupSnapshot(ctx context.Context, vg VolumeGroup, name string) (VolumeGroupSnapshot, error)
// GetMirrorSource returns the source of the mirror for the given volume or group.
GetMirrorSource(ctx context.Context, volumeID string,
rep *replication.ReplicationSource) ([]Volume, Mirror, error)
}