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https://gitlab.com/qemu-project/qemu
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qcow2: Add falloc and full preallocation option
preallocation=falloc allocates disk space by posix_fallocate(), preallocation=full allocates disk space by writing zeros to disk. Both modes imply preallocation=metadata. Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Hu Tao
Kevin Wolf
parent
06247428be
commit
0e4271b711
4 changed files with 90 additions and 43 deletions
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@ -1772,6 +1772,56 @@ static int qcow2_create2(const char *filename, int64_t total_size,
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Error *local_err = NULL;
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int ret;
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if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) {
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int64_t meta_size = 0;
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uint64_t nreftablee, nrefblocke, nl1e, nl2e;
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int64_t aligned_total_size = align_offset(total_size, cluster_size);
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/* header: 1 cluster */
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meta_size += cluster_size;
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/* total size of L2 tables */
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nl2e = aligned_total_size / cluster_size;
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nl2e = align_offset(nl2e, cluster_size / sizeof(uint64_t));
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meta_size += nl2e * sizeof(uint64_t);
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/* total size of L1 tables */
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nl1e = nl2e * sizeof(uint64_t) / cluster_size;
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nl1e = align_offset(nl1e, cluster_size / sizeof(uint64_t));
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meta_size += nl1e * sizeof(uint64_t);
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/* total size of refcount blocks
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*
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* note: every host cluster is reference-counted, including metadata
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* (even refcount blocks are recursively included).
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* Let:
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* a = total_size (this is the guest disk size)
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* m = meta size not including refcount blocks and refcount tables
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* c = cluster size
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* y1 = number of refcount blocks entries
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* y2 = meta size including everything
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* then,
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* y1 = (y2 + a)/c
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* y2 = y1 * sizeof(u16) + y1 * sizeof(u16) * sizeof(u64) / c + m
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* we can get y1:
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* y1 = (a + m) / (c - sizeof(u16) - sizeof(u16) * sizeof(u64) / c)
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*/
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nrefblocke = (aligned_total_size + meta_size + cluster_size) /
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(cluster_size - sizeof(uint16_t) -
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1.0 * sizeof(uint16_t) * sizeof(uint64_t) / cluster_size);
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nrefblocke = align_offset(nrefblocke, cluster_size / sizeof(uint16_t));
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meta_size += nrefblocke * sizeof(uint16_t);
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/* total size of refcount tables */
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nreftablee = nrefblocke * sizeof(uint16_t) / cluster_size;
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nreftablee = align_offset(nreftablee, cluster_size / sizeof(uint64_t));
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meta_size += nreftablee * sizeof(uint64_t);
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qemu_opt_set_number(opts, BLOCK_OPT_SIZE,
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aligned_total_size + meta_size);
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qemu_opt_set(opts, BLOCK_OPT_PREALLOC, PreallocMode_lookup[prealloc]);
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}
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ret = bdrv_create_file(filename, opts, &local_err);
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if (ret < 0) {
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error_propagate(errp, local_err);
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@ -1877,7 +1927,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
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}
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/* And if we're supposed to preallocate metadata, do that now */
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if (prealloc == PREALLOC_MODE_METADATA) {
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if (prealloc != PREALLOC_MODE_OFF) {
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BDRVQcowState *s = bs->opaque;
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qemu_co_mutex_lock(&s->lock);
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ret = preallocate(bs);
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@ -1958,14 +2008,6 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp)
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flags |= BLOCK_FLAG_LAZY_REFCOUNTS;
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}
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if (prealloc != PREALLOC_MODE_OFF &&
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prealloc != PREALLOC_MODE_METADATA) {
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ret = -EINVAL;
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error_setg(errp, "Unsupported preallocate mode: %s",
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PreallocMode_lookup[prealloc]);
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goto finish;
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}
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if (backing_file && prealloc != PREALLOC_MODE_OFF) {
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error_setg(errp, "Backing file and preallocation cannot be used at "
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"the same time");
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@ -2526,7 +2568,8 @@ static QemuOptsList qcow2_create_opts = {
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{
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.name = BLOCK_OPT_PREALLOC,
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.type = QEMU_OPT_STRING,
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.help = "Preallocation mode (allowed values: off, metadata)"
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.help = "Preallocation mode (allowed values: off, metadata, "
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"falloc, full)"
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},
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{
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.name = BLOCK_OPT_LAZY_REFCOUNTS,
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@ -584,9 +584,11 @@ sizes can improve the image file size whereas larger cluster sizes generally
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provide better performance.
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@item preallocation
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Preallocation mode (allowed values: off, metadata). An image with preallocated
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metadata is initially larger but can improve performance when the image needs
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to grow.
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Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
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@code{full}). An image with preallocated metadata is initially larger but can
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improve performance when the image needs to grow. @code{falloc} and @code{full}
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preallocations are like the same options of @code{raw} format, but sets up
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metadata also.
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@item lazy_refcounts
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If this option is set to @code{on}, reference count updates are postponed with
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@ -476,9 +476,11 @@ sizes can improve the image file size whereas larger cluster sizes generally
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provide better performance.
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@item preallocation
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Preallocation mode (allowed values: off, metadata). An image with preallocated
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metadata is initially larger but can improve performance when the image needs
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to grow.
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Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
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@code{full}). An image with preallocated metadata is initially larger but can
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improve performance when the image needs to grow. @code{falloc} and @code{full}
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preallocations are like the same options of @code{raw} format, but sets up
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metadata also.
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@item lazy_refcounts
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If this option is set to @code{on}, reference count updates are postponed with
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@ -64,7 +64,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -76,7 +76,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -88,7 +88,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -100,7 +100,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -112,7 +112,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -124,7 +124,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -136,7 +136,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -148,7 +148,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -175,7 +175,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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Testing: create -o help
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@ -253,7 +253,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -265,7 +265,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -277,7 +277,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -289,7 +289,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -301,7 +301,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -313,7 +313,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -325,7 +325,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -337,7 +337,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -364,7 +364,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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Testing: convert -o help
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@ -431,7 +431,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -443,7 +443,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -455,7 +455,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -467,7 +467,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -479,7 +479,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -491,7 +491,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -503,7 +503,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -515,7 +515,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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nocow Turn off copy-on-write (valid only on btrfs)
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@ -544,7 +544,7 @@ backing_file File name of a base image
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backing_fmt Image format of the base image
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encryption Encrypt the image
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cluster_size qcow2 cluster size
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preallocation Preallocation mode (allowed values: off, metadata)
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preallocation Preallocation mode (allowed values: off, metadata, falloc, full)
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lazy_refcounts Postpone refcount updates
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Testing: convert -o help
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