Hi,
El 26/07/16 a las 17:28, Alexandre DERUMIER escribió:
I wonder if this couldn't be fixed directly in rbd.c block driver
I have send a patch, can you test ?
I got it, will be testing this morning and will report back, this really
seems the correct thing to do (fix the rbd block "bug").
----- Mail original -----
De: "aderumier" <aderum...@odiso.com>
À: "pve-devel" <pve-devel@pve.proxmox.com>
Envoyé: Mardi 26 Juillet 2016 16:46:58
Objet: Re: [pve-devel] [PATCH] Add patch to improve qmrestore to RBD,
activating writeback cache.
I wonder if this couldn't be fixed directly in rbd.c block driver
currently:
block/rbd.c
if (flags & BDRV_O_NOCACHE) {
rados_conf_set(s->cluster, "rbd_cache", "false");
} else {
rados_conf_set(s->cluster, "rbd_cache", "true");
}
and in block.c
int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
{
*flags &= ~BDRV_O_CACHE_MASK;
if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
*writethrough = false;
*flags |= BDRV_O_NOCACHE;
} else if (!strcmp(mode, "directsync")) {
*writethrough = true;
*flags |= BDRV_O_NOCACHE;
} else if (!strcmp(mode, "writeback")) {
*writethrough = false;
} else if (!strcmp(mode, "unsafe")) {
*writethrough = false;
*flags |= BDRV_O_NO_FLUSH;
} else if (!strcmp(mode, "writethrough")) {
*writethrough = true;
} else {
return -1;
}
return 0;
}
as in qemu-img convert we don't send flush and in vma restore too, we use
BDRV_O_NO_FLUSH.
I think we should add in rbd.c something like
if (flags & BDRV_O_NOCACHE) {
rados_conf_set(s->cluster, "rbd_cache", "false");
} else {
rados_conf_set(s->cluster, "rbd_cache", "true");
}
+ if (flags & BDRV_O_NO_FLUSH) {
+ rados_conf_set(s->cluster, "rbd_cache_writethrough_until_flush", "false");
+ }
I really think it's the right way (or it's impossible to use unsafe cache
option) and could be pushed to qemu upsteam.
----- Mail original -----
De: "Eneko Lacunza" <elacu...@binovo.es>
À: "pve-devel" <pve-devel@pve.proxmox.com>
Envoyé: Mardi 26 Juillet 2016 16:05:52
Objet: Re: [pve-devel] [PATCH] Add patch to improve qmrestore to RBD,
activating writeback cache.
Hi,
I'm unsure about wether it would be better to have one patch or two
independent patches?
El 26/07/16 a las 16:02, Alexandre DERUMIER escribió:
Hi,
I think that qemu-img convert have the same problem
I have found a commit from 2015
https://git.greensocs.com/fkonrad/mttcg/commit/80ccf93b884a2edab5ec62634758e942bba81b7c
By default it don't send flush (cache=unsafe), and the commit add a flush on
image closing, because some storage like sheepdog,
can't do the flush by themself.
maybe can we add the same flush just after the opening in convert.
----- Mail original -----
De: "Eneko Lacunza" <elacu...@binovo.es>
À: "pve-devel" <pve-devel@pve.proxmox.com>
Cc: "Eneko Lacunza" <elacu...@pve-test.binovo.net>
Envoyé: Mardi 26 Juillet 2016 15:18:55
Objet: [pve-devel] [PATCH] Add patch to improve qmrestore to RBD, activating
writeback cache.
From: Eneko Lacunza <elacu...@pve-test.binovo.net>
Signed-off-by: Eneko Lacunza <elacu...@pve-test.binovo.net>
---
.../0054-vma-force-enable-rbd-cache-for-qmrestore.patch | 17 +++++++++++++++++
debian/patches/series | 1 +
2 files changed, 18 insertions(+)
create mode 100644
debian/patches/pve/0054-vma-force-enable-rbd-cache-for-qmrestore.patch
diff --git
a/debian/patches/pve/0054-vma-force-enable-rbd-cache-for-qmrestore.patch
b/debian/patches/pve/0054-vma-force-enable-rbd-cache-for-qmrestore.patch
new file mode 100644
index 0000000..d9722c7
--- /dev/null
+++ b/debian/patches/pve/0054-vma-force-enable-rbd-cache-for-qmrestore.patch
@@ -0,0 +1,17 @@
+Issue a bogus flush so that Ceph activates rbd cache, accelerating qmrestore
to RBD.
+---
+Index: b/vma.c
+===================================================================
+--- a/vma.c
++++ b/vma.c
+@@ -335,6 +335,9 @@ static int extract_content(int argc, cha
+
+ BlockDriverState *bs = blk_bs(blk);
+
++ /* This is needed to activate rbd cache (writeback/coalesce) */
++ bdrv_flush(bs);
++
+ if (vma_reader_register_bs(vmar, i, bs, write_zero, &errp) < 0) {
+ g_error("%s", error_get_pretty(errp));
+ }
+
diff --git a/debian/patches/series b/debian/patches/series
index 3614309..c858a30 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -51,6 +51,7 @@ pve/0050-fix-possible-unitialised-return-value.patch
pve/0051-net-NET_CLIENT_OPTIONS_KIND_MAX-changed.patch
pve/0052-vnc-refactor-to-QIOChannelSocket.patch
pve/0053-vma-use-BlockBackend-on-extract.patch
+pve/0054-vma-force-enable-rbd-cache-for-qmrestore.patch
#see https://bugs.launchpad.net/qemu/+bug/1488363?comments=all
extra/0001-Revert-target-i386-disable-LINT0-after-reset.patch
extra/0001-i386-kvmvapic-initialise-imm32-variable.patch
--
Zuzendari Teknikoa / Director Técnico
Binovo IT Human Project, S.L.
Telf. 943493611
943324914
Astigarraga bidea 2, planta 6 dcha., ofi. 3-2; 20180 Oiartzun (Gipuzkoa)
www.binovo.es
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