Raid array is not automatically detected.

My apologies if this is not the right place to ask this question. Hopefully it is.

I created a RAID5 array with:

mdadm --create /dev/md0 --level=5 --raid-devices=5 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm -D /dev/md0 verifies the devices has a persistent super-block, but upon reboot, /dev/md0 does not get automatically assembled (an hence is not a installable/bootable device).

I have created several raid1 arrays and one raid5 array this way and have never had this problem. In all fairness, this is the first time I have used mdadm for the job. Usually, I boot to something like SysRescueCD, used raidtools to create my array and then reboot with my Slackware install CD.

Anyone know why this might be happening?

Quoted 11 lines · Bryan Christ

My apologies if this is not the right place to ask this question. Hopefully it is.

I created a RAID5 array with:

mdadm --create /dev/md0 --level=5 --raid-devices=5 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm -D /dev/md0 verifies the devices has a persistent super-block, but upon reboot, /dev/md0 does not get automatically assembled (an hence is not a installable/bootable device).

I have created several raid1 arrays and one raid5 array this way and have never had this problem. In all fairness, this is the first time I have used mdadm for the job. Usually, I boot to something like SysRescueCD, used raidtools to create my array and then reboot with my Slackware install CD.

Anyone know why this might be happening?

Are you trying to boot on this raid device? I believe there is a limitation as what raid type you can boot off of (IIRC. only raid0 and raid1).

My apologies if this is not the right place to ask this question. Hopefully it is.

I created a RAID5 array with:

mdadm --create /dev/md0 --level=5 --raid-devices=5 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm -D /dev/md0 verifies the devices has a persistent super-block, but upon reboot, /dev/md0 does not get automatically assembled (an hence is not a installable/bootable device).

I have created several raid1 arrays and one raid5 array this way and have never had this problem. In all fairness, this is the first time I have used mdadm for the job. Usually, I boot to something like SysRescueCD, used raidtools to create my array and then reboot with my Slackware install CD.

Anyone know why this might be happening?

Quoted 11 lines · Bryan Christ

My apologies if this is not the right place to ask this question. Hopefully it is.

I created a RAID5 array with:

mdadm --create /dev/md0 --level=5 --raid-devices=5 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm -D /dev/md0 verifies the devices has a persistent super-block, but upon reboot, /dev/md0 does not get automatically assembled (an hence is not a installable/bootable device).

I have created several raid1 arrays and one raid5 array this way and have never had this problem. In all fairness, this is the first time I have used mdadm for the job. Usually, I boot to something like SysRescueCD, used raidtools to create my array and then reboot with my Slackware install CD.

Anyone know why this might be happening?

Old type arrays are assembled due to having the proper partition type, 0xfd "Linux auto RAID" and are assembled by the kernel. All others are assembled by mdadm running out of initrd or similar, and failures there result from not having a proper config file in the initrd image.

IIRC raidtools does set the array partitions to the auto-assemble partition type. Hope that points you in the right direction. Running
"fdisk -l"
as root will let you see all the partitions, types, etc, for everything on your system.

I may be wrong, I thought auto-assemble only worked with type 0 or 1.

Signature · 8 lines

bill davidsen <[email protected]>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979

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Quoted 26 lines · Bill Davidsen

Quoted 11 lines · Bryan Christ

My apologies if this is not the right place to ask this question. Hopefully it is.

I created a RAID5 array with:

mdadm --create /dev/md0 --level=5 --raid-devices=5 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm -D /dev/md0 verifies the devices has a persistent super-block, but upon reboot, /dev/md0 does not get automatically assembled (an hence is not a installable/bootable device).

I have created several raid1 arrays and one raid5 array this way and have never had this problem. In all fairness, this is the first time I have used mdadm for the job. Usually, I boot to something like SysRescueCD, used raidtools to create my array and then reboot with my Slackware install CD.

Anyone know why this might be happening?

Old type arrays are assembled due to having the proper partition type, 0xfd "Linux auto RAID" and are assembled by the kernel. All others are assembled by mdadm running out of initrd or similar, and failures there result from not having a proper config file in the initrd image.

IIRC raidtools does set the array partitions to the auto-assemble partition type. Hope that points you in the right direction. Running
"fdisk -l"
as root will let you see all the partitions, types, etc, for everything on your system.

I may be wrong, I thought auto-assemble only worked with type 0 or 1.

Signature · 3 lines

bill davidsen <[email protected]>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979

Quoted 5 lines

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I use auto-assemble (in conjunction with Debian's own startup scripts) and for my root RAID1 device,swap and /boot, it is automatically taken care of by the kernel. For RAID5, it seems to work the same:

[   58.919378] RAID5 conf printout:
[   58.919418]  --- rd:10 wd:10
[   58.919457]  disk 0, o:1, dev:sdc1
[   58.919498]  disk 1, o:1, dev:sdd1
[   58.919539]  disk 2, o:1, dev:sde1
[   58.919579]  disk 3, o:1, dev:sdf1
[   58.919619]  disk 4, o:1, dev:sdg1
[   58.919659]  disk 5, o:1, dev:sdh1
[   58.919719]  disk 6, o:1, dev:sdi1
[   58.919759]  disk 7, o:1, dev:sdj1
[   58.919799]  disk 8, o:1, dev:sdk1
[   58.919839]  disk 9, o:1, dev:sdl1

Justin.

Quoted 36 lines · Justin Piszcz

Quoted 31 lines · Bill Davidsen

Quoted 11 lines · Bryan Christ

My apologies if this is not the right place to ask this question. Hopefully it is.

I created a RAID5 array with:

mdadm --create /dev/md0 --level=5 --raid-devices=5 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm -D /dev/md0 verifies the devices has a persistent super-block, but upon reboot, /dev/md0 does not get automatically assembled (an hence is not a installable/bootable device).

I have created several raid1 arrays and one raid5 array this way and have never had this problem. In all fairness, this is the first time I have used mdadm for the job. Usually, I boot to something like SysRescueCD, used raidtools to create my array and then reboot with my Slackware install CD.

Anyone know why this might be happening?

Old type arrays are assembled due to having the proper partition type, 0xfd "Linux auto RAID" and are assembled by the kernel. All others are assembled by mdadm running out of initrd or similar, and failures there result from not having a proper config file in the initrd image.

IIRC raidtools does set the array partitions to the auto-assemble partition type. Hope that points you in the right direction. Running
"fdisk -l"
as root will let you see all the partitions, types, etc, for everything on your system.

I may be wrong, I thought auto-assemble only worked with type 0 or 1.

Signature · 8 lines

bill davidsen <[email protected]>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979

-
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

Quoted 2 lines

I use auto-assemble (in conjunction with Debian's own startup scripts) and for my root RAID1 device,swap and /boot, it is automatically taken care of by the kernel. For RAID5, it seems to work the same:

Are those partitions type "Linux RAID" or is the assemble being run from the init scripts? I suspect the latter.

Quoted 14 lines

[   58.919378] RAID5 conf printout:
[   58.919418]  --- rd:10 wd:10
[   58.919457]  disk 0, o:1, dev:sdc1
[   58.919498]  disk 1, o:1, dev:sdd1
[   58.919539]  disk 2, o:1, dev:sde1
[   58.919579]  disk 3, o:1, dev:sdf1
[   58.919619]  disk 4, o:1, dev:sdg1
[   58.919659]  disk 5, o:1, dev:sdh1
[   58.919719]  disk 6, o:1, dev:sdi1
[   58.919759]  disk 7, o:1, dev:sdj1
[   58.919799]  disk 8, o:1, dev:sdk1
[   58.919839]  disk 9, o:1, dev:sdl1

Justin.

Quoted 13 lines · Bill Davidsen

Quoted 11 lines · Bryan Christ

My apologies if this is not the right place to ask this question. Hopefully it is.

I created a RAID5 array with:

mdadm --create /dev/md0 --level=5 --raid-devices=5 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm -D /dev/md0 verifies the devices has a persistent super-block, but upon reboot, /dev/md0 does not get automatically assembled (an hence is not a installable/bootable device).

I have created several raid1 arrays and one raid5 array this way and have never had this problem. In all fairness, this is the first time I have used mdadm for the job. Usually, I boot to something like SysRescueCD, used raidtools to create my array and then reboot with my Slackware install CD.

Anyone know why this might be happening?

Quoted 18 lines

Old type arrays are assembled due to having the proper partition type, 0xfd "Linux auto RAID" and are assembled by the kernel. All others are assembled by mdadm running out of initrd or similar, and failures there result from not having a proper config file in the initrd image.

IIRC raidtools does set the array partitions to the auto-assemble partition type. Hope that points you in the right direction. Running
"fdisk -l"
as root will let you see all the partitions, types, etc, for everything on your system.

I may be wrong, I thought auto-assemble only worked with type 0 or 1.

Signature · 8 lines

bill davidsen <[email protected]>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979

-
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

I use auto-assemble (in conjunction with Debian's own startup scripts) and for my root RAID1 device,swap and /boot, it is automatically taken care of by the kernel. For RAID5, it seems to work the same:

[   58.919378] RAID5 conf printout:
[   58.919418]  --- rd:10 wd:10
[   58.919457]  disk 0, o:1, dev:sdc1
[   58.919498]  disk 1, o:1, dev:sdd1
[   58.919539]  disk 2, o:1, dev:sde1
[   58.919579]  disk 3, o:1, dev:sdf1
[   58.919619]  disk 4, o:1, dev:sdg1
[   58.919659]  disk 5, o:1, dev:sdh1
[   58.919719]  disk 6, o:1, dev:sdi1
[   58.919759]  disk 7, o:1, dev:sdj1
[   58.919799]  disk 8, o:1, dev:sdk1
[   58.919839]  disk 9, o:1, dev:sdl1

Justin.

I do have the type set to 0xfd. Others have said that auto-assemble only works on RAID 0 and 1, but just as Justin mentioned, I too have another box with RAID5 that gets auto assembled by the kernel (also no initrd). I expected the same behavior when I built this array--again using mdadm instead of raidtools.

Quoted 5 lines · Bryan Christ

I do have the type set to 0xfd. Others have said that auto-assemble only works on RAID 0 and 1, but just as Justin mentioned, I too have another box with RAID5 that gets auto assembled by the kernel (also no initrd). I expected the same behavior when I built this array--again using mdadm instead of raidtools.

Any md arrays with partition type 0xfd using a 0.9 superblock should be auto-assembled by a standard kernel.

Quoted 9 lines · David Greaves

Quoted 5 lines · Bryan Christ

I do have the type set to 0xfd. Others have said that auto-assemble only works on RAID 0 and 1, but just as Justin mentioned, I too have another box with RAID5 that gets auto assembled by the kernel (also no initrd). I expected the same behavior when I built this array--again using mdadm instead of raidtools.

Any md arrays with partition type 0xfd using a 0.9 superblock should be auto-assembled by a standard kernel.

no... debian (and probably ubuntu) do not build md into the kernel, they build it as a module, and the module does not auto-detect 0xfd. i don't know anything about slackware, but i just felt it worth commenting that "a standard kernel" is not really descriptive enough.

-dean

Quoted 6 lines · David Greaves

Quoted 5 lines · Bryan Christ

I do have the type set to 0xfd. Others have said that auto-assemble only works on RAID 0 and 1, but just as Justin mentioned, I too have another box with RAID5 that gets auto assembled by the kernel (also no initrd). I expected the same behavior when I built this array--again using mdadm instead of raidtools.

Quoted 2 lines

Any md arrays with partition type 0xfd using a 0.9 superblock should be auto-assembled by a standard kernel.

no... debian (and probably ubuntu) do not build md into the kernel, they build it as a module, and the module does not auto-detect 0xfd. i don't know anything about slackware, but i just felt it worth commenting that "a standard kernel" is not really descriptive enough.

Quoted 1 line · Bryan Christ

I do have the type set to 0xfd. Others have said that auto-assemble only works on RAID 0 and 1, but just as Justin mentioned, I too have another box with RAID5 that gets auto assembled by the kernel (also no initrd). I expected the same behavior when I built this array--again using mdadm instead of raidtools.

Any md arrays with partition type 0xfd using a 0.9 superblock should be auto-assembled by a standard kernel.

If you want to boot from them you must ensure the kernel image is on a partition that the bootloader can read - ie RAID 0. This is nothing to do with auto-assembly.

So some questions:
* are the partitions 0xfd ? yes.
* is the kernel standard?
* are the superblocks version 0.9? (mdadm --examine /dev/component)

David

I'm now very confused...

When I run mdadm --examine /dev/md0 I get the error message: No superblock detected on /dev/md0

However, when I run mdadm -D /dev/md0 the report clearly states "Superblock is persistent"

Quoted 1 line · David Greaves

* are the superblocks version 0.9? (mdadm --examine /dev/component)

Quoted 1 line · Bryan Christ

I'm now very confused...

It's all that top-posting...

Quoted 6 lines

When I run mdadm --examine /dev/md0 I get the error message: No superblock detected on /dev/md0

However, when I run mdadm -D /dev/md0 the report clearly states "Superblock is persistent"

Quoted 1 line · David Greaves

* are the superblocks version 0.9? (mdadm --examine /dev/component)

See where it says 'component' ? :)

I wish mdadm --detail and --examine were just aliases and the output varied according to whether you looked at a component (eg /dev/sda1) or an md device (/dev/md0)

I get that wrong *all* the time...

David

See where it says 'component' ? :)

I wish mdadm --detail and --examine were just aliases and the output varied according to whether you looked at a component (eg /dev/sda1) or an md device (/dev/md0)

I get that wrong *all* the time...

Quoted 7 lines · David Greaves

See where it says 'component' ? :)

I wish mdadm --detail and --examine were just aliases and the output varied according to whether you looked at a component (eg /dev/sda1) or an md device (/dev/md0)

Quoted 1 line

I get that wrong *all* the time...

Neil, if you will take that as a suggestion, you can take this as a second. While I have learned to use the correct option most of the time, this is a case where the software can make an unambiguous decision to avoid the human having to stop and think which option is appropriate.