Skip to contentSkip to conversation

spare group

DISCUSSION Tomka Gergely 2 participants 7 messages Jun 11, 2007 – Jun 13, 2007 MD RAID

lore
Share & tools
lore

Tomka Gergely

author
#0 lore raw

Good day!

I have problems with spare-groups. The problem: spare groups dont work for me. How can i use ths function?

The test :

# mdadm26 -D /dev/md0
/dev/md0:
        Version : 01.02.03
  Creation Time : Mon Jun 11 15:25:23 2007
     Raid Level : raid5
     Array Size : 19534720 (18.63 GiB 20.00 GB)
  Used Dev Size : 19534720 (9.31 GiB 10.00 GB)
   Raid Devices : 3
  Total Devices : 3
Preferred Minor : 0
    Persistence : Superblock is persistent

Update Time : Mon Jun 11 16:05:21 2007
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 1
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 64K

Name : ursula:T1 (local to host ursula) UUID : 3e420024:281f9bb1:fd9ef39b:c18153b1
Events : 10

Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 17 1 active sync /dev/sdb1
3 8 33 2 active sync /dev/sdc1

0 8 1 - faulty spare /dev/sda1

# mdadm26 -D /dev/md1
/dev/md1:
        Version : 01.02.03
  Creation Time : Mon Jun 11 15:35:40 2007
     Raid Level : raid5
     Array Size : 19534720 (18.63 GiB 20.00 GB)
  Used Dev Size : 19534720 (9.31 GiB 10.00 GB)
   Raid Devices : 3
  Total Devices : 4
Preferred Minor : 1
    Persistence : Superblock is persistent

Update Time : Mon Jun 11 15:38:23 2007
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1

Layout : left-symmetric
Chunk Size : 64K

Name : ursula:T2 (local to host ursula) UUID : fb8ece28:9a6a31f8:700f37f6:7ee91bcf
Events : 6

Number Major Minor RaidDevice State
0 8 49 0 active sync /dev/sdd1
1 8 65 1 active sync /dev/sde1
3 8 81 2 active sync /dev/sdf1

4 8 97 - spare /dev/sdg1

# cat /etc/mdadm/mdadm.conf
DEVICE /dev/sd[a-g]1

HOMEHOST ursula

ARRAY /dev/md1 level=raid5 devices=/dev/sd[defg]1 num-devices=3 spares=1 spare-group=ubul name=ursula:T2 UUID=fb8ece28:9a6a31f8:700f37f6:7ee91bcf ARRAY /dev/md0 level=raid5 devices=/dev/sd[abc]1 num-devices=3 spare-group=ubul name=ursula:T1 UUID=3e420024:281f9bb1:fd9ef39b:c18153b1

According to the source:

* If an array has active < raid && spare == 0 && spare_group !=NULL
* Look for another array with spare > 0 and active == raid and same spare_group
* if found, choose a device and hotremove/hotadd

This is not happening. What is my mistake?

tg

#1 lore raw
Quoted 11 lines · On Monday June 11, [email protected] wrote:
# cat /etc/mdadm/mdadm.conf
DEVICE /dev/sd[a-g]1

HOMEHOST ursula

ARRAY /dev/md1 level=raid5 devices=/dev/sd[defg]1 num-devices=3 spares=1 spare-group=ubul name=ursula:T2 UUID=fb8ece28:9a6a31f8:700f37f6:7ee91bcf
ARRAY /dev/md0 level=raid5 devices=/dev/sd[abc]1 num-devices=3 spare-group=ubul name=ursula:T1 UUID=3e420024:281f9bb1:fd9ef39b:c18153b1

You don't want the "devices=" entries in there. If you leave them there, and sdg1 does get moved to md0, then on the next restart, md0 won't get assembled properly.

Quoted 9 lines

According to the source:

* If an array has active < raid && spare == 0 && spare_group !=NULL
* Look for another array with spare > 0 and active == raid and same spare_group
* if found, choose a device and hotremove/hotadd

This is not happening. What is my mistake?

Is "mdadm --monitor" running? That is required to perform spare-migration.

NeilBrown

author
#2 lore raw

Neil Brown írta:

Quoted 7 lines · On Monday June 11, [email protected] wrote:
Quoted 2 lines

ARRAY /dev/md1 level=raid5 devices=/dev/sd[defg]1 num-devices=3 spares=1 spare-group=ubul name=ursula:T2 UUID=fb8ece28:9a6a31f8:700f37f6:7ee91bcf ARRAY /dev/md0 level=raid5 devices=/dev/sd[abc]1 num-devices=3 spare-group=ubul name=ursula:T1 UUID=3e420024:281f9bb1:fd9ef39b:c18153b1

You don't want the "devices=" entries in there. If you leave them there, and sdg1 does get moved to md0, then on the next restart, md0 won't get assembled properly.

Thanks.

Quoted 10 lines
Quoted 7 lines

According to the source:

* If an array has active < raid && spare == 0 && spare_group !=NULL
* Look for another array with spare > 0 and active == raid and same spare_group
* if found, choose a device and hotremove/hotadd

This is not happening. What is my mistake?

Is "mdadm --monitor" running? That is required to perform spare-migration.

Yes, of course.

tg
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

#3 lore raw
Quoted 7 lines · On Tuesday June 12, [email protected] wrote:
Quoted 7 lines
Quoted 7 lines

According to the source:

* If an array has active < raid && spare == 0 && spare_group !=NULL
* Look for another array with spare > 0 and active == raid and same spare_group
* if found, choose a device and hotremove/hotadd

Quoted 6 lines
Quoted 4 lines
Quoted 1 line

This is not happening. What is my mistake?

Is "mdadm --monitor" running? That is required to perform spare-migration.

Yes, of course.

Good - I need to get the obvious things out of the way first :-)

(reads code).

Ahhh. You are using version-1 superblocks aren't you? That code only works for version-0.90 superblocks. That was careless of me. It shouldn't be hard to make it work more generally, but it looks like it will be slightly more than trivial. I'll try to get you a patch in the next day or so (feel free to remind me if I seem to have forgotten).

Thanks for testing and reporting this problem.

NeilBrown

author
#4 lore raw

Neil Brown írta:

Quoted 9 lines

(reads code).

Ahhh. You are using version-1 superblocks aren't you? That code only works for version-0.90 superblocks. That was careless of me. It shouldn't be hard to make it work more generally, but it looks like it will be slightly more than trivial. I'll try to get you a patch in the next day or so (feel free to remind me if I seem to have forgotten).

Quoted 3 lines

Thanks for testing and reporting this problem.

NeilBrown

# mdadm26 --detail /dev/md0
/dev/md0:
        Version : 00.90.03
  Creation Time : Tue Jun 12 10:31:08 2007
     Raid Level : raid5
     Array Size : 19534848 (18.63 GiB 20.00 GB)
  Used Dev Size : 9767424 (9.31 GiB 10.00 GB)
   Raid Devices : 3
  Total Devices : 4
Preferred Minor : 0
    Persistence : Superblock is persistent

Update Time : Tue Jun 12 10:33:35 2007
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1

Layout : left-symmetric
Chunk Size : 64K

UUID : 5fd83926:01739a55:36458d87:119f8994 (local to host
ursula)
Events : 0.4

Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
2 8 33 2 active sync /dev/sdc1

3 8 49 - spare /dev/sdd1

/dev/md1:

        Version : 00.90.03

Creation Time : Tue Jun 12 10:31:29 2007
Raid Level : raid5
Array Size : 19534848 (18.63 GiB 20.00 GB)
Used Dev Size : 9767424 (9.31 GiB 10.00 GB)
Raid Devices : 3
Total Devices : 3
Preferred Minor : 1
Persistence : Superblock is persistent

Update Time : Tue Jun 12 10:36:18 2007
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 1
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 64K

UUID : 815d6fc4:a55c2602:36458d87:119f8994 (local to host
ursula)
Events : 0.6

Number Major Minor RaidDevice State
0 8 65 0 active sync /dev/sde1
1 8 81 1 active sync /dev/sdf1
2 0 0 2 removed

3 8 97 - faulty spare /dev/sdg1

ARRAY /dev/md1 level=raid5 num-devices=3 spare-group=ubul UUID=815d6fc4:a55c2602:36458d87:119f8994 ARRAY /dev/md0 level=raid5 num-devices=3 spares=1 spare-group=ubul UUID=5fd83926:01739a55:36458d87:119f8994

I am very sorry, but it wont works with .9 superblocks also :( We missing something small, but important here. Before you start to code. mdadm was running in monitor mode, and reported a Fail. mdadm is the latest version, 2.6.2.

tg
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

#5 lore raw
Quoted 7 lines · On Tuesday June 12, [email protected] wrote:

I am very sorry, but it wont works with .9 superblocks also :( We missing something small, but important here. Before you start to code. mdadm was running in monitor mode, and reported a Fail. mdadm is the latest version, 2.6.2.

tg

Hmmm.....
[tests code]

Yes, you are right. It looks like a bug was introduced in 2.6 which broke various aspects of --monitor. I guess I need to add some --monitor tests to my regression test suite.

This patch should fix it.

Thanks again,
NeilBrown

-------------------------------
Fix spare migration and other problems with --monitor.

2.6 broke --monitor in various ways, including spare migration stopped working. This fixes it.

### Diffstat output

 ./Monitor.c |    1 +
 1 file changed, 1 insertion(+)
Monitor.c +1 -0
diff .prev/Monitor.c ./Monitor.c
@@ -328,6 +328,7 @@ int Monitor(mddev_dev_t devlist,
 			for (i=0; i<MaxDisks && i <= array.raid_disks + array.nr_disks;
 			     i++) {
 				mdu_disk_info_t disc;
+				disc.number = i;
 				if (ioctl(fd, GET_DISK_INFO, &disc) >= 0) {
 					info[i].state = disc.state;
 					info[i].major = disc.major;
author
#6 lore raw

Neil Brown írta:

Quoted 7 lines · On Tuesday June 12, [email protected] wrote:
Quoted 3 lines

I am very sorry, but it wont works with .9 superblocks also :( We missing something small, but important here. Before you start to code. mdadm was running in monitor mode, and reported a Fail. mdadm is the latest version, 2.6.2.

tg

Hmmm..... [tests code]

Quoted 8 lines

Yes, you are right. It looks like a bug was introduced in 2.6 which broke various aspects of --monitor. I guess I need to add some --monitor tests to my regression test suite.

This patch should fix it.

Thanks again,
NeilBrown

Thanks, the patch is working.

tg
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html