mirror_zfs/cmd/raidz_test/raidz_bench.c
Don Brady 5caeef02fa
RAID-Z expansion feature
This feature allows disks to be added one at a time to a RAID-Z group,
expanding its capacity incrementally.  This feature is especially useful
for small pools (typically with only one RAID-Z group), where there
isn't sufficient hardware to add capacity by adding a whole new RAID-Z
group (typically doubling the number of disks).

== Initiating expansion ==

A new device (disk) can be attached to an existing RAIDZ vdev, by
running `zpool attach POOL raidzP-N NEW_DEVICE`, e.g. `zpool attach tank
raidz2-0 sda`.  The new device will become part of the RAIDZ group.  A
"raidz expansion" will be initiated, and the new device will contribute
additional space to the RAIDZ group once the expansion completes.

The `feature@raidz_expansion` on-disk feature flag must be `enabled` to
initiate an expansion, and it remains `active` for the life of the pool.
In other words, pools with expanded RAIDZ vdevs can not be imported by
older releases of the ZFS software.

== During expansion ==

The expansion entails reading all allocated space from existing disks in
the RAIDZ group, and rewriting it to the new disks in the RAIDZ group
(including the newly added device).

The expansion progress can be monitored with `zpool status`.

Data redundancy is maintained during (and after) the expansion.  If a
disk fails while the expansion is in progress, the expansion pauses
until the health of the RAIDZ vdev is restored (e.g. by replacing the
failed disk and waiting for reconstruction to complete).

The pool remains accessible during expansion.  Following a reboot or
export/import, the expansion resumes where it left off.

== After expansion ==

When the expansion completes, the additional space is available for use,
and is reflected in the `available` zfs property (as seen in `zfs list`,
`df`, etc).

Expansion does not change the number of failures that can be tolerated
without data loss (e.g. a RAIDZ2 is still a RAIDZ2 even after
expansion).

A RAIDZ vdev can be expanded multiple times.

After the expansion completes, old blocks remain with their old
data-to-parity ratio (e.g. 5-wide RAIDZ2, has 3 data to 2 parity), but
distributed among the larger set of disks.  New blocks will be written
with the new data-to-parity ratio (e.g. a 5-wide RAIDZ2 which has been
expanded once to 6-wide, has 4 data to 2 parity).  However, the RAIDZ
vdev's "assumed parity ratio" does not change, so slightly less space
than is expected may be reported for newly-written blocks, according to
`zfs list`, `df`, `ls -s`, and similar tools.

Sponsored-by: The FreeBSD Foundation
Sponsored-by: iXsystems, Inc.
Sponsored-by: vStack
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Authored-by: Matthew Ahrens <mahrens@delphix.com>
Contributions-by: Fedor Uporov <fuporov.vstack@gmail.com>
Contributions-by: Stuart Maybee <stuart.maybee@comcast.net>
Contributions-by: Thorsten Behrens <tbehrens@outlook.com>
Contributions-by: Fmstrat <nospam@nowsci.com>
Contributions-by: Don Brady <dev.fs.zfs@gmail.com>
Signed-off-by: Don Brady <dev.fs.zfs@gmail.com>
Closes #15022
2023-11-08 10:19:41 -08:00

243 lines
5.9 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (C) 2016 Gvozden Nešković. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <sys/zio.h>
#include <sys/vdev_raidz.h>
#include <sys/vdev_raidz_impl.h>
#include <stdio.h>
#include "raidz_test.h"
#define GEN_BENCH_MEMORY (((uint64_t)1ULL)<<32)
#define REC_BENCH_MEMORY (((uint64_t)1ULL)<<29)
#define BENCH_ASHIFT 12
#define MIN_CS_SHIFT BENCH_ASHIFT
#define MAX_CS_SHIFT SPA_MAXBLOCKSHIFT
static zio_t zio_bench;
static raidz_map_t *rm_bench;
static size_t max_data_size = SPA_MAXBLOCKSIZE;
static void
bench_init_raidz_map(void)
{
zio_bench.io_offset = 0;
zio_bench.io_size = max_data_size;
/*
* To permit larger column sizes these have to be done
* allocated using aligned alloc instead of zio_abd_buf_alloc
*/
zio_bench.io_abd = raidz_alloc(max_data_size);
init_zio_abd(&zio_bench);
}
static void
bench_fini_raidz_maps(void)
{
/* tear down golden zio */
raidz_free(zio_bench.io_abd, max_data_size);
memset(&zio_bench, 0, sizeof (zio_t));
}
static inline void
run_gen_bench_impl(const char *impl)
{
int fn, ncols;
uint64_t ds, iter_cnt, iter, disksize;
hrtime_t start;
double elapsed, d_bw;
/* Benchmark generate functions */
for (fn = 0; fn < RAIDZ_GEN_NUM; fn++) {
for (ds = MIN_CS_SHIFT; ds <= MAX_CS_SHIFT; ds++) {
/* create suitable raidz_map */
ncols = rto_opts.rto_dcols + fn + 1;
zio_bench.io_size = 1ULL << ds;
if (rto_opts.rto_expand) {
rm_bench = vdev_raidz_map_alloc_expanded(
&zio_bench,
rto_opts.rto_ashift, ncols+1, ncols,
fn+1, rto_opts.rto_expand_offset,
0, B_FALSE);
} else {
rm_bench = vdev_raidz_map_alloc(&zio_bench,
BENCH_ASHIFT, ncols, fn+1);
}
/* estimate iteration count */
iter_cnt = GEN_BENCH_MEMORY;
iter_cnt /= zio_bench.io_size;
start = gethrtime();
for (iter = 0; iter < iter_cnt; iter++)
vdev_raidz_generate_parity(rm_bench);
elapsed = NSEC2SEC((double)(gethrtime() - start));
disksize = (1ULL << ds) / rto_opts.rto_dcols;
d_bw = (double)iter_cnt * (double)disksize;
d_bw /= (1024.0 * 1024.0 * elapsed);
LOG(D_ALL, "%10s, %8s, %zu, %10llu, %lf, %lf, %u\n",
impl,
raidz_gen_name[fn],
rto_opts.rto_dcols,
(1ULL<<ds),
d_bw,
d_bw * (double)(ncols),
(unsigned)iter_cnt);
vdev_raidz_map_free(rm_bench);
}
}
}
static void
run_gen_bench(void)
{
char **impl_name;
LOG(D_INFO, DBLSEP "\nBenchmarking parity generation...\n\n");
LOG(D_ALL, "impl, math, dcols, iosize, disk_bw, total_bw, iter\n");
for (impl_name = (char **)raidz_impl_names; *impl_name != NULL;
impl_name++) {
if (vdev_raidz_impl_set(*impl_name) != 0)
continue;
run_gen_bench_impl(*impl_name);
}
}
static void
run_rec_bench_impl(const char *impl)
{
int fn, ncols, nbad;
uint64_t ds, iter_cnt, iter, disksize;
hrtime_t start;
double elapsed, d_bw;
static const int tgt[7][3] = {
{1, 2, 3}, /* rec_p: bad QR & D[0] */
{0, 2, 3}, /* rec_q: bad PR & D[0] */
{0, 1, 3}, /* rec_r: bad PQ & D[0] */
{2, 3, 4}, /* rec_pq: bad R & D[0][1] */
{1, 3, 4}, /* rec_pr: bad Q & D[0][1] */
{0, 3, 4}, /* rec_qr: bad P & D[0][1] */
{3, 4, 5} /* rec_pqr: bad & D[0][1][2] */
};
for (fn = 0; fn < RAIDZ_REC_NUM; fn++) {
for (ds = MIN_CS_SHIFT; ds <= MAX_CS_SHIFT; ds++) {
/* create suitable raidz_map */
ncols = rto_opts.rto_dcols + PARITY_PQR;
zio_bench.io_size = 1ULL << ds;
/*
* raidz block is too short to test
* the requested method
*/
if (zio_bench.io_size / rto_opts.rto_dcols <
(1ULL << BENCH_ASHIFT))
continue;
if (rto_opts.rto_expand) {
rm_bench = vdev_raidz_map_alloc_expanded(
&zio_bench,
BENCH_ASHIFT, ncols+1, ncols,
PARITY_PQR,
rto_opts.rto_expand_offset, 0, B_FALSE);
} else {
rm_bench = vdev_raidz_map_alloc(&zio_bench,
BENCH_ASHIFT, ncols, PARITY_PQR);
}
/* estimate iteration count */
iter_cnt = (REC_BENCH_MEMORY);
iter_cnt /= zio_bench.io_size;
/* calculate how many bad columns there are */
nbad = MIN(3, raidz_ncols(rm_bench) -
raidz_parity(rm_bench));
start = gethrtime();
for (iter = 0; iter < iter_cnt; iter++)
vdev_raidz_reconstruct(rm_bench, tgt[fn], nbad);
elapsed = NSEC2SEC((double)(gethrtime() - start));
disksize = (1ULL << ds) / rto_opts.rto_dcols;
d_bw = (double)iter_cnt * (double)(disksize);
d_bw /= (1024.0 * 1024.0 * elapsed);
LOG(D_ALL, "%10s, %8s, %zu, %10llu, %lf, %lf, %u\n",
impl,
raidz_rec_name[fn],
rto_opts.rto_dcols,
(1ULL<<ds),
d_bw,
d_bw * (double)ncols,
(unsigned)iter_cnt);
vdev_raidz_map_free(rm_bench);
}
}
}
static void
run_rec_bench(void)
{
char **impl_name;
LOG(D_INFO, DBLSEP "\nBenchmarking data reconstruction...\n\n");
LOG(D_ALL, "impl, math, dcols, iosize, disk_bw, total_bw, iter\n");
for (impl_name = (char **)raidz_impl_names; *impl_name != NULL;
impl_name++) {
if (vdev_raidz_impl_set(*impl_name) != 0)
continue;
run_rec_bench_impl(*impl_name);
}
}
void
run_raidz_benchmark(void)
{
bench_init_raidz_map();
run_gen_bench();
run_rec_bench();
bench_fini_raidz_maps();
}