storage: Add TRIM algorithm to storage volume API

This new algorithm adds support for wiping volumes using TRIM.

It does not overwrite all the data in a volume, but it tells the
backing storage pool/driver that all bytes in a volume can be
discarded.

It depends on the backing storage pool how this is handled.

A SCSI backend might send UNMAP commands to remove all data present
on a LUN.

A Ceph backend might use rbd_discard() to instruct the Ceph cluster
that all data on that RBD volume can be discarded.

Signed-off-by: Wido den Hollander <wido@widodh.nl>
This commit is contained in:
Wido den Hollander 2016-01-27 11:20:07 +01:00 committed by John Ferlan
parent f226ecbfbb
commit 63cdc92f04
5 changed files with 22 additions and 4 deletions

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@ -4,7 +4,7 @@
* Description: Provides APIs for the management of storage pools and volumes
* Author: Daniel Veillard <veillard@redhat.com>
*
* Copyright (C) 2006-2014 Red Hat, Inc.
* Copyright (C) 2006-2016 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -153,6 +153,9 @@ typedef enum {
VIR_STORAGE_VOL_WIPE_ALG_RANDOM = 8, /* 1-pass random */
VIR_STORAGE_VOL_WIPE_ALG_TRIM = 9, /* 1-pass, trim all data on the
volume by using TRIM or DISCARD */
# ifdef VIR_ENUM_SENTINELS
VIR_STORAGE_VOL_WIPE_ALG_LAST
/*

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@ -2105,6 +2105,10 @@ virStorageBackendVolWipeLocal(virConnectPtr conn ATTRIBUTE_UNUSED,
case VIR_STORAGE_VOL_WIPE_ALG_RANDOM:
alg_char = "random";
break;
case VIR_STORAGE_VOL_WIPE_ALG_TRIM:
virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
_("'trim' algorithm not supported"));
goto cleanup;
case VIR_STORAGE_VOL_WIPE_ALG_LAST:
virReportError(VIR_ERR_INVALID_ARG,
_("unsupported algorithm %d"),

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@ -831,6 +831,7 @@ virStorageBackendRBDVolWipe(virConnectPtr conn,
case VIR_STORAGE_VOL_WIPE_ALG_PFITZNER7:
case VIR_STORAGE_VOL_WIPE_ALG_PFITZNER33:
case VIR_STORAGE_VOL_WIPE_ALG_RANDOM:
case VIR_STORAGE_VOL_WIPE_ALG_TRIM:
case VIR_STORAGE_VOL_WIPE_ALG_LAST:
virReportError(VIR_ERR_INVALID_ARG, _("unsupported algorithm %d"),
algorithm);

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@ -906,7 +906,7 @@ static const vshCmdOptDef opts_vol_wipe[] = {
VIR_ENUM_DECL(virStorageVolWipeAlgorithm)
VIR_ENUM_IMPL(virStorageVolWipeAlgorithm, VIR_STORAGE_VOL_WIPE_ALG_LAST,
"zero", "nnsa", "dod", "bsi", "gutmann", "schneier",
"pfitzner7", "pfitzner33", "random");
"pfitzner7", "pfitzner33", "random", "trim");
static bool
cmdVolWipe(vshControl *ctl, const vshCmd *cmd)

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@ -3546,9 +3546,19 @@ B<Supported algorithms>
pfitzner7 - Roy Pfitzner's 7-random-pass method: random x7.
pfitzner33 - Roy Pfitzner's 33-random-pass method: random x33.
random - 1-pass pattern: random.
trim - 1-pass trimming the volume using TRIM or DISCARD
B<Note>: The availability of algorithms may be limited by the version
of the C<scrub> binary installed on the host.
B<Note>: The C<scrub> binary will be used to handle the 'nnsa', 'dod',
'bsi', 'gutmann', 'schneier', 'pfitzner7' and 'pfitzner33' algorithms.
The availability of the algorithms may be limited by the version of
the C<scrub> binary installed on the host. The 'zero' algorithm will
write zeroes to the entire volume. For some volumes, such as sparse
or rbd volumes, this may result in completely filling the volume with
zeroes making it appear to be completely full. As an alternative, the
'trim' algorithm does not overwrite all the data in a volume, rather
it expects the storage driver to be able to discard all bytes in a
volume. It is up to the storage driver to handle how the discarding
occurs. Not all storage drivers or volume types can support 'trim'.
=item B<vol-dumpxml> [I<--pool> I<pool-or-uuid>] I<vol-name-or-key-or-path>