Re: 2 drives failed, one "active", one with wrong event count
From: Neil Brown <hidden>
Date: 2010-02-04 01:03:12
Subsystem:
the rest · Maintainer:
Linus Torvalds
On Mon, 1 Feb 2010 08:13:24 +0100 (CET) Mikael Abrahamsson [off-list ref] wrote:
On Mon, 1 Feb 2010, Neil Brown wrote:quoted
You might know that nothing has been written to the array since the device with the lower event count was removed, but md doesn't know that. Any device with an old event count could have old and so cannot be trusted (unless you assemble with --force meaning that you are taking responsibility).I did use --force, but it seems in the state "one drive with lower event count and another one with 0x2", the event count on the drive isn't forcably updated and since there is a 0x2 drive, the array isn't started. I had the same situation again this morning (changing controller next), but this time I had bitmaps enabled so recovery of the array with --assemble --force took just a few seconds. Really nice.
Right... I understand now.
Fixed with the following patch which will be in 3.1.2.
Thanks,
NeilBrown
commit 921d9e164fd3f6203d1b0cf2424b793043afd001
Author: NeilBrown [off-list ref]
Date: Thu Feb 4 12:02:09 2010 +1100
Assemble: fix --force assembly of v1.x arrays which are recovering.
1.x metadata allows a device to be a member of the array while it
is still recoverying. So it is a working member, but is not
completely in-sync.
mdadm/assemble does not understand this distinction and assumes that a
work member is fully in-sync for the purpose of determining if there
are enough in-sync devices for the array to be functional.
So collect the 'recovery_start' value from the metadata and use it in
assemble when determining how useful a given device is.
Reported-by: Mikael Abrahamsson [off-list ref]
Signed-off-by: NeilBrown [off-list ref]
diff --git a/Assemble.c b/Assemble.c
index 7f90048..e4d6181 100644
--- a/Assemble.c
+++ b/Assemble.c@@ -800,7 +800,8 @@ int Assemble(struct supertype *st, char *mddev, if (devices[j].i.events+event_margin >= devices[most_recent].i.events) { devices[j].uptodate = 1; - if (i < content->array.raid_disks) { + if (i < content->array.raid_disks && + devices[j].i.recovery_start == MaxSector) { okcnt++; avail[i]=1; } else
@@ -822,6 +823,7 @@ int Assemble(struct supertype *st, char *mddev, int j = best[i]; if (j>=0 && !devices[j].uptodate && + devices[j].i.recovery_start == MaxSector && (chosen_drive < 0 || devices[j].i.events > devices[chosen_drive].i.events))
diff --git a/super-ddf.c b/super-ddf.c
index 3e30229..870efd8 100644
--- a/super-ddf.c
+++ b/super-ddf.c@@ -1369,6 +1369,7 @@ static void getinfo_super_ddf(struct supertype *st, struct mdinfo *info) info->disk.state = (1 << MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE); + info->recovery_start = MaxSector; info->reshape_active = 0; info->name[0] = 0;
@@ -1427,6 +1428,7 @@ static void getinfo_super_ddf_bvd(struct supertype *st, struct mdinfo *info) info->container_member = ddf->currentconf->vcnum; + info->recovery_start = MaxSector; info->resync_start = 0; if (!(ddf->virt->entries[info->container_member].state & DDF_state_inconsistent) &&
diff --git a/super-intel.c b/super-intel.c
index 91479a2..bbdcb51 100644
--- a/super-intel.c
+++ b/super-intel.c@@ -1452,6 +1452,7 @@ static void getinfo_super_imsm_volume(struct supertype *st, struct mdinfo *info) info->data_offset = __le32_to_cpu(map->pba_of_lba0); info->component_size = __le32_to_cpu(map->blocks_per_member); memset(info->uuid, 0, sizeof(info->uuid)); + info->recovery_start = MaxSector; if (map->map_state == IMSM_T_STATE_UNINITIALIZED || dev->vol.dirty) { info->resync_start = 0;
@@ -1559,6 +1560,7 @@ static void getinfo_super_imsm(struct supertype *st, struct mdinfo *info) info->disk.number = -1; info->disk.state = 0; info->name[0] = 0; + info->recovery_start = MaxSector; if (super->disks) { __u32 reserved = imsm_reserved_sectors(super, super->disks);
diff --git a/super0.c b/super0.c
index 0485a3a..5c6b7d7 100644
--- a/super0.c
+++ b/super0.c@@ -372,6 +372,7 @@ static void getinfo_super0(struct supertype *st, struct mdinfo *info) uuid_from_super0(st, info->uuid); + info->recovery_start = MaxSector; if (sb->minor_version > 90 && (sb->reshape_position+1) != 0) { info->reshape_active = 1; info->reshape_progress = sb->reshape_position;
diff --git a/super1.c b/super1.c
index 85bb598..40fbb81 100644
--- a/super1.c
+++ b/super1.c@@ -612,6 +612,11 @@ static void getinfo_super1(struct supertype *st, struct mdinfo *info) strncpy(info->name, sb->set_name, 32); info->name[32] = 0; + if (sb->feature_map & __le32_to_cpu(MD_FEATURE_RECOVERY_OFFSET)) + info->recovery_start = __le32_to_cpu(sb->recovery_offset); + else + info->recovery_start = MaxSector; + if (sb->feature_map & __le32_to_cpu(MD_FEATURE_RESHAPE_ACTIVE)) { info->reshape_active = 1; info->reshape_progress = __le64_to_cpu(sb->reshape_position);