Converting from Raid 5 to 6

Converting from Raid 5 to 6

[Michael Busby]

At the moment i have a raid5 setup with 5 disks, i am looking to add a
6th disk and change from raid 5 to raid 6

having looked at Neil's site i have found the following command, and
just want to double check this is still the recommend way of
converting

mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup

also would i need to add the extra disk before or after the command?

cheers
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Re: Converting from Raid 5 to 6

[Mathias Burén]

On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
> At the moment i have a raid5 setup with 5 disks, i am looking to add a
> 6th disk and change from raid 5 to raid 6
>
> having looked at Neil's site i have found the following command, and
> just want to double check this is still the recommend way of
> converting
>
> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
>
> also would i need to add the extra disk before or after the command?
>
> cheers
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Hi,

I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
partition it as required. Then add the drive to the array (I think
it'll become a spare?). Then you can grow it.

Make sure you're using the latest mdadm tools available.

Regards,
Mathias
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Re: Converting from Raid 5 to 6

[Michael Busby]

should the speed be very slow when doing this progress, its a lot
slower than a normal grow

reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec

On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
> On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
>> At the moment i have a raid5 setup with 5 disks, i am looking to add a
>> 6th disk and change from raid 5 to raid 6
>>
>> having looked at Neil's site i have found the following command, and
>> just want to double check this is still the recommend way of
>> converting
>>
>> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
>>
>> also would i need to add the extra disk before or after the command?
>>
>> cheers
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>
> Hi,
>
> I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
> partition it as required. Then add the drive to the array (I think
> it'll become a spare?). Then you can grow it.
>
> Make sure you're using the latest mdadm tools available.
>
> Regards,
> Mathias
>
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Re: Converting from Raid 5 to 6

[Mathias Burén]

On 24 October 2011 17:03, Michael Busby <michael.a.busby@gmail.com> wrote:
> should the speed be very slow when doing this progress, its a lot
> slower than a normal grow
>
> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
>
> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
>> On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
>>> At the moment i have a raid5 setup with 5 disks, i am looking to add a
>>> 6th disk and change from raid 5 to raid 6
>>>
>>> having looked at Neil's site i have found the following command, and
>>> just want to double check this is still the recommend way of
>>> converting
>>>
>>> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
>>>
>>> also would i need to add the extra disk before or after the command?
>>>
>>> cheers
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>
>>
>> Hi,
>>
>> I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
>> partition it as required. Then add the drive to the array (I think
>> it'll become a spare?). Then you can grow it.
>>
>> Make sure you're using the latest mdadm tools available.
>>
>> Regards,
>> Mathias
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

(please reply to the bottom of the email)

What CPU are you using? What are the min/max kbps settings on the md
device? What does top (or htop) show you?

/M
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Re: Converting from Raid 5 to 6

[Michael Busby]

On 24 October 2011 17:27, Mathias Burén <mathias.buren@gmail.com> wrote:
> On 24 October 2011 17:03, Michael Busby <michael.a.busby@gmail.com> wrote:
>> should the speed be very slow when doing this progress, its a lot
>> slower than a normal grow
>>
>> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
>>
>> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
>>> On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
>>>> At the moment i have a raid5 setup with 5 disks, i am looking to add a
>>>> 6th disk and change from raid 5 to raid 6
>>>>
>>>> having looked at Neil's site i have found the following command, and
>>>> just want to double check this is still the recommend way of
>>>> converting
>>>>
>>>> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
>>>>
>>>> also would i need to add the extra disk before or after the command?
>>>>
>>>> cheers
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>>
>>>
>>> Hi,
>>>
>>> I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
>>> partition it as required. Then add the drive to the array (I think
>>> it'll become a spare?). Then you can grow it.
>>>
>>> Make sure you're using the latest mdadm tools available.
>>>
>>> Regards,
>>> Mathias
>>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>
> (please reply to the bottom of the email)
>
> What CPU are you using? What are the min/max kbps settings on the md
> device? What does top (or htop) show you?
>
> /M
>

Its a AMD 1.3ghz, in a HP microserver

max = 2000000
min = 200000

top - 17:33:49 up 4 days, 18:57,  2 users,  load average: 1.19, 1.32, 1.34
Tasks: 102 total,   1 running, 101 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.3%us,  4.8%sy,  0.0%ni, 61.6%id, 32.9%wa,  0.0%hi,  0.3%si,  0.0%st
Mem:   2958840k total,  2519944k used,   438896k free,   140868k buffers
Swap:  3143676k total,   376112k used,  2767564k free,  1122084k cached
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Re: Converting from Raid 5 to 6

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 2232 bytes --]

On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
wrote:

> should the speed be very slow when doing this progress, its a lot
> slower than a normal grow

Yes.
The array is being reshaped in-place.  i.e. data is being read from part of
the array, rearranged, and written back to the same part of the array.
As you can imagine, this is risky - a crash will leave an inconsistent state.
Hence the backup file.  Everything in the array is first written to the
backup file, then back to the array.  So it is slow.

A "normal" grow is writing to somewhere where there is no valid data, so it
doesn't need the backup.

I do have a plan to make this faster.... but I have lots of plans and little
time.

NeilBrown




> 
> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
> 
> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
> > On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
> >> At the moment i have a raid5 setup with 5 disks, i am looking to add a
> >> 6th disk and change from raid 5 to raid 6
> >>
> >> having looked at Neil's site i have found the following command, and
> >> just want to double check this is still the recommend way of
> >> converting
> >>
> >> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
> >>
> >> also would i need to add the extra disk before or after the command?
> >>
> >> cheers
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>
> >
> > Hi,
> >
> > I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
> > partition it as required. Then add the drive to the array (I think
> > it'll become a spare?). Then you can grow it.
> >
> > Make sure you're using the latest mdadm tools available.
> >
> > Regards,
> > Mathias
> >
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


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Re: Converting from Raid 5 to 6

[Michael Busby]

Ok thanks, i have 1 small issue, when added the extra disk its been
maked as spare, is this normal?

Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
[raid4] [raid10]
md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1]
      7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18
[6/5] [UUUUU_]
      [>....................]  reshape =  3.0% (59244544/1953513984)
finish=11122.8min speed=2837K/sec




On 24 October 2011 21:14, NeilBrown <neilb@suse.de> wrote:
> On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
> wrote:
>
>> should the speed be very slow when doing this progress, its a lot
>> slower than a normal grow
>
> Yes.
> The array is being reshaped in-place.  i.e. data is being read from part of
> the array, rearranged, and written back to the same part of the array.
> As you can imagine, this is risky - a crash will leave an inconsistent state.
> Hence the backup file.  Everything in the array is first written to the
> backup file, then back to the array.  So it is slow.
>
> A "normal" grow is writing to somewhere where there is no valid data, so it
> doesn't need the backup.
>
> I do have a plan to make this faster.... but I have lots of plans and little
> time.
>
> NeilBrown
>
>
>
>
>>
>> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
>>
>> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
>> > On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
>> >> At the moment i have a raid5 setup with 5 disks, i am looking to add a
>> >> 6th disk and change from raid 5 to raid 6
>> >>
>> >> having looked at Neil's site i have found the following command, and
>> >> just want to double check this is still the recommend way of
>> >> converting
>> >>
>> >> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
>> >>
>> >> also would i need to add the extra disk before or after the command?
>> >>
>> >> cheers
>> >> --
>> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>> >> the body of a message to majordomo@vger.kernel.org
>> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> >>
>> >
>> > Hi,
>> >
>> > I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
>> > partition it as required. Then add the drive to the array (I think
>> > it'll become a spare?). Then you can grow it.
>> >
>> > Make sure you're using the latest mdadm tools available.
>> >
>> > Regards,
>> > Mathias
>> >
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
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Re: Converting from Raid 5 to 6

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 3397 bytes --]

On Mon, 24 Oct 2011 21:19:22 +0100 Michael Busby <michael.a.busby@gmail.com>
wrote:

> Ok thanks, i have 1 small issue, when added the extra disk its been
> maked as spare, is this normal?
> 
> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
> [raid4] [raid10]
> md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1]
>       7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18
> [6/5] [UUUUU_]
>       [>....................]  reshape =  3.0% (59244544/1953513984)
> finish=11122.8min speed=2837K/sec
> 

It looks like the extra drive was added after you started the grow.

So it is still a spare.
Once the grow finishes you will have a singly-degraded RAID6.
Then it will immediately start recovering the missing device to the spare.

Did you add the extra drive after starting the grow - or before??

NeilBrown



> 
> 
> 
> On 24 October 2011 21:14, NeilBrown <neilb@suse.de> wrote:
> > On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
> > wrote:
> >
> >> should the speed be very slow when doing this progress, its a lot
> >> slower than a normal grow
> >
> > Yes.
> > The array is being reshaped in-place.  i.e. data is being read from part of
> > the array, rearranged, and written back to the same part of the array.
> > As you can imagine, this is risky - a crash will leave an inconsistent state.
> > Hence the backup file.  Everything in the array is first written to the
> > backup file, then back to the array.  So it is slow.
> >
> > A "normal" grow is writing to somewhere where there is no valid data, so it
> > doesn't need the backup.
> >
> > I do have a plan to make this faster.... but I have lots of plans and little
> > time.
> >
> > NeilBrown
> >
> >
> >
> >
> >>
> >> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
> >>
> >> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
> >> > On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
> >> >> At the moment i have a raid5 setup with 5 disks, i am looking to add a
> >> >> 6th disk and change from raid 5 to raid 6
> >> >>
> >> >> having looked at Neil's site i have found the following command, and
> >> >> just want to double check this is still the recommend way of
> >> >> converting
> >> >>
> >> >> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
> >> >>
> >> >> also would i need to add the extra disk before or after the command?
> >> >>
> >> >> cheers
> >> >> --
> >> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> >> >> the body of a message to majordomo@vger.kernel.org
> >> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >> >>
> >> >
> >> > Hi,
> >> >
> >> > I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
> >> > partition it as required. Then add the drive to the array (I think
> >> > it'll become a spare?). Then you can grow it.
> >> >
> >> > Make sure you're using the latest mdadm tools available.
> >> >
> >> > Regards,
> >> > Mathias
> >> >
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
> >


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Re: Converting from Raid 5 to 6

[Michael Busby]

I was sure i added the device before, but when rebooted the system it
has seemed to lose the extra drive and i had already restarted the
grow command with out checking the disk was there, so more than likely
a mistake by me



On 24 October 2011 21:39, NeilBrown <neilb@suse.de> wrote:
> On Mon, 24 Oct 2011 21:19:22 +0100 Michael Busby <michael.a.busby@gmail.com>
> wrote:
>
>> Ok thanks, i have 1 small issue, when added the extra disk its been
>> maked as spare, is this normal?
>>
>> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
>> [raid4] [raid10]
>> md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1]
>>       7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18
>> [6/5] [UUUUU_]
>>       [>....................]  reshape =  3.0% (59244544/1953513984)
>> finish=11122.8min speed=2837K/sec
>>
>
> It looks like the extra drive was added after you started the grow.
>
> So it is still a spare.
> Once the grow finishes you will have a singly-degraded RAID6.
> Then it will immediately start recovering the missing device to the spare.
>
> Did you add the extra drive after starting the grow - or before??
>
> NeilBrown
>
>


>
>>
>>
>>
>> On 24 October 2011 21:14, NeilBrown <neilb@suse.de> wrote:
>> > On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
>> > wrote:
>> >
>> >> should the speed be very slow when doing this progress, its a lot
>> >> slower than a normal grow
>> >
>> > Yes.
>> > The array is being reshaped in-place.  i.e. data is being read from part of
>> > the array, rearranged, and written back to the same part of the array.
>> > As you can imagine, this is risky - a crash will leave an inconsistent state.
>> > Hence the backup file.  Everything in the array is first written to the
>> > backup file, then back to the array.  So it is slow.
>> >
>> > A "normal" grow is writing to somewhere where there is no valid data, so it
>> > doesn't need the backup.
>> >
>> > I do have a plan to make this faster.... but I have lots of plans and little
>> > time.
>> >
>> > NeilBrown
>> >
>> >
>> >
>> >
>> >>
>> >> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
>> >>
>> >> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
>> >> > On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
>> >> >> At the moment i have a raid5 setup with 5 disks, i am looking to add a
>> >> >> 6th disk and change from raid 5 to raid 6
>> >> >>
>> >> >> having looked at Neil's site i have found the following command, and
>> >> >> just want to double check this is still the recommend way of
>> >> >> converting
>> >> >>
>> >> >> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
>> >> >>
>> >> >> also would i need to add the extra disk before or after the command?
>> >> >>
>> >> >> cheers
>> >> >> --
>> >> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>> >> >> the body of a message to majordomo@vger.kernel.org
>> >> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> >> >>
>> >> >
>> >> > Hi,
>> >> >
>> >> > I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
>> >> > partition it as required. Then add the drive to the array (I think
>> >> > it'll become a spare?). Then you can grow it.
>> >> >
>> >> > Make sure you're using the latest mdadm tools available.
>> >> >
>> >> > Regards,
>> >> > Mathias
>> >> >
>> >> --
>> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>> >> the body of a message to majordomo@vger.kernel.org
>> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> >
>> >
>
>
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Re: Converting from Raid 5 to 6

[Michael Busby]

Sorry to bring up a old thread, last night i had a power cut and this
morning when the power has come back i have tried to boot the server,
but the raid will not assemble on using a live CD i have found that
one of the disk is reporting "possibly out of date" is there any way
to force this disk back in? the bigger problem i have is that my
external caddie has died so i was running a degraded raid 6 but now it
is only starting with 4 out of 6 devices. is there anyway to get this
back?

i have though about recreating the array using the --assume-clean
option but not sure if that's a good idea

any help will be much appreciated



On 24 October 2011 21:47, Michael Busby <michael.a.busby@gmail.com> wrote:
>
> I was sure i added the device before, but when rebooted the system it
> has seemed to lose the extra drive and i had already restarted the
> grow command with out checking the disk was there, so more than likely
> a mistake by me
>
>
>
> On 24 October 2011 21:39, NeilBrown <neilb@suse.de> wrote:
> > On Mon, 24 Oct 2011 21:19:22 +0100 Michael Busby <michael.a.busby@gmail.com>
> > wrote:
> >
> >> Ok thanks, i have 1 small issue, when added the extra disk its been
> >> maked as spare, is this normal?
> >>
> >> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
> >> [raid4] [raid10]
> >> md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1]
> >>       7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18
> >> [6/5] [UUUUU_]
> >>       [>....................]  reshape =  3.0% (59244544/1953513984)
> >> finish=11122.8min speed=2837K/sec
> >>
> >
> > It looks like the extra drive was added after you started the grow.
> >
> > So it is still a spare.
> > Once the grow finishes you will have a singly-degraded RAID6.
> > Then it will immediately start recovering the missing device to the spare.
> >
> > Did you add the extra drive after starting the grow - or before??
> >
> > NeilBrown
> >
> >
>
>
> >
> >>
> >>
> >>
> >> On 24 October 2011 21:14, NeilBrown <neilb@suse.de> wrote:
> >> > On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
> >> > wrote:
> >> >
> >> >> should the speed be very slow when doing this progress, its a lot
> >> >> slower than a normal grow
> >> >
> >> > Yes.
> >> > The array is being reshaped in-place.  i.e. data is being read from part of
> >> > the array, rearranged, and written back to the same part of the array.
> >> > As you can imagine, this is risky - a crash will leave an inconsistent state.
> >> > Hence the backup file.  Everything in the array is first written to the
> >> > backup file, then back to the array.  So it is slow.
> >> >
> >> > A "normal" grow is writing to somewhere where there is no valid data, so it
> >> > doesn't need the backup.
> >> >
> >> > I do have a plan to make this faster.... but I have lots of plans and little
> >> > time.
> >> >
> >> > NeilBrown
> >> >
> >> >
> >> >
> >> >
> >> >>
> >> >> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
> >> >>
> >> >> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
> >> >> > On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
> >> >> >> At the moment i have a raid5 setup with 5 disks, i am looking to add a
> >> >> >> 6th disk and change from raid 5 to raid 6
> >> >> >>
> >> >> >> having looked at Neil's site i have found the following command, and
> >> >> >> just want to double check this is still the recommend way of
> >> >> >> converting
> >> >> >>
> >> >> >> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
> >> >> >>
> >> >> >> also would i need to add the extra disk before or after the command?
> >> >> >>
> >> >> >> cheers
> >> >> >> --
> >> >> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> >> >> >> the body of a message to majordomo@vger.kernel.org
> >> >> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >> >> >>
> >> >> >
> >> >> > Hi,
> >> >> >
> >> >> > I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
> >> >> > partition it as required. Then add the drive to the array (I think
> >> >> > it'll become a spare?). Then you can grow it.
> >> >> >
> >> >> > Make sure you're using the latest mdadm tools available.
> >> >> >
> >> >> > Regards,
> >> >> > Mathias
> >> >> >
> >> >> --
> >> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> >> >> the body of a message to majordomo@vger.kernel.org
> >> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >> >
> >> >
> >
> >
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Converting from Raid 5 to 6

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 5486 bytes --]

On Sat, 30 Nov 2013 22:13:58 +0000 Michael Busby <michael.a.busby@gmail.com>
wrote:

> Sorry to bring up a old thread, last night i had a power cut and this
> morning when the power has come back i have tried to boot the server,
> but the raid will not assemble on using a live CD i have found that
> one of the disk is reporting "possibly out of date" is there any way
> to force this disk back in? the bigger problem i have is that my
> external caddie has died so i was running a degraded raid 6 but now it
> is only starting with 4 out of 6 devices. is there anyway to get this
> back?

It's really hard to know what is possible without precise details.
Output of "mdadm -E" for each member device is always a good idea.
If you are having trouble assembling, then output of the assemble command
with -vv added never goes astray.
Have you tried adding "-f" to the assemble command.  Often helps and is
unlikely to hurt.

> 
> i have though about recreating the array using the --assume-clean
> option but not sure if that's a good idea

Not a good idea except as a very last resort.

NeilBrown


> 
> any help will be much appreciated
> 
> 
> 
> On 24 October 2011 21:47, Michael Busby <michael.a.busby@gmail.com> wrote:
> >
> > I was sure i added the device before, but when rebooted the system it
> > has seemed to lose the extra drive and i had already restarted the
> > grow command with out checking the disk was there, so more than likely
> > a mistake by me
> >
> >
> >
> > On 24 October 2011 21:39, NeilBrown <neilb@suse.de> wrote:
> > > On Mon, 24 Oct 2011 21:19:22 +0100 Michael Busby <michael.a.busby@gmail.com>
> > > wrote:
> > >
> > >> Ok thanks, i have 1 small issue, when added the extra disk its been
> > >> maked as spare, is this normal?
> > >>
> > >> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
> > >> [raid4] [raid10]
> > >> md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1]
> > >>       7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18
> > >> [6/5] [UUUUU_]
> > >>       [>....................]  reshape =  3.0% (59244544/1953513984)
> > >> finish=11122.8min speed=2837K/sec
> > >>
> > >
> > > It looks like the extra drive was added after you started the grow.
> > >
> > > So it is still a spare.
> > > Once the grow finishes you will have a singly-degraded RAID6.
> > > Then it will immediately start recovering the missing device to the spare.
> > >
> > > Did you add the extra drive after starting the grow - or before??
> > >
> > > NeilBrown
> > >
> > >
> >
> >
> > >
> > >>
> > >>
> > >>
> > >> On 24 October 2011 21:14, NeilBrown <neilb@suse.de> wrote:
> > >> > On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
> > >> > wrote:
> > >> >
> > >> >> should the speed be very slow when doing this progress, its a lot
> > >> >> slower than a normal grow
> > >> >
> > >> > Yes.
> > >> > The array is being reshaped in-place.  i.e. data is being read from part of
> > >> > the array, rearranged, and written back to the same part of the array.
> > >> > As you can imagine, this is risky - a crash will leave an inconsistent state.
> > >> > Hence the backup file.  Everything in the array is first written to the
> > >> > backup file, then back to the array.  So it is slow.
> > >> >
> > >> > A "normal" grow is writing to somewhere where there is no valid data, so it
> > >> > doesn't need the backup.
> > >> >
> > >> > I do have a plan to make this faster.... but I have lots of plans and little
> > >> > time.
> > >> >
> > >> > NeilBrown
> > >> >
> > >> >
> > >> >
> > >> >
> > >> >>
> > >> >> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
> > >> >>
> > >> >> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
> > >> >> > On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
> > >> >> >> At the moment i have a raid5 setup with 5 disks, i am looking to add a
> > >> >> >> 6th disk and change from raid 5 to raid 6
> > >> >> >>
> > >> >> >> having looked at Neil's site i have found the following command, and
> > >> >> >> just want to double check this is still the recommend way of
> > >> >> >> converting
> > >> >> >>
> > >> >> >> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
> > >> >> >>
> > >> >> >> also would i need to add the extra disk before or after the command?
> > >> >> >>
> > >> >> >> cheers
> > >> >> >> --
> > >> >> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> > >> >> >> the body of a message to majordomo@vger.kernel.org
> > >> >> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > >> >> >>
> > >> >> >
> > >> >> > Hi,
> > >> >> >
> > >> >> > I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
> > >> >> > partition it as required. Then add the drive to the array (I think
> > >> >> > it'll become a spare?). Then you can grow it.
> > >> >> >
> > >> >> > Make sure you're using the latest mdadm tools available.
> > >> >> >
> > >> >> > Regards,
> > >> >> > Mathias
> > >> >> >
> > >> >> --
> > >> >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> > >> >> the body of a message to majordomo@vger.kernel.org
> > >> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > >> >
> > >> >
> > >
> > >


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Re: Converting from Raid 5 to 6

[Michael Busby]

Using -f seems to have worked just running e2fsck now

When running a command like mdadm --assemble -- force --verbose
/dev/md0 /dev/sa[abcde] how important it the drive order?


Sent from my iPad

> On 2 Dec 2013, at 05:51 am, NeilBrown <neilb@suse.de> wrote:
>
> On Sat, 30 Nov 2013 22:13:58 +0000 Michael Busby <michael.a.busby@gmail.com>
> wrote:
>
>> Sorry to bring up a old thread, last night i had a power cut and this
>> morning when the power has come back i have tried to boot the server,
>> but the raid will not assemble on using a live CD i have found that
>> one of the disk is reporting "possibly out of date" is there any way
>> to force this disk back in? the bigger problem i have is that my
>> external caddie has died so i was running a degraded raid 6 but now it
>> is only starting with 4 out of 6 devices. is there anyway to get this
>> back?
>
> It's really hard to know what is possible without precise details.
> Output of "mdadm -E" for each member device is always a good idea.
> If you are having trouble assembling, then output of the assemble command
> with -vv added never goes astray.
> Have you tried adding "-f" to the assemble command.  Often helps and is
> unlikely to hurt.
>
>>
>> i have though about recreating the array using the --assume-clean
>> option but not sure if that's a good idea
>
> Not a good idea except as a very last resort.
>
> NeilBrown
>
>
>>
>> any help will be much appreciated
>>
>>
>>
>>> On 24 October 2011 21:47, Michael Busby <michael.a.busby@gmail.com> wrote:
>>>
>>> I was sure i added the device before, but when rebooted the system it
>>> has seemed to lose the extra drive and i had already restarted the
>>> grow command with out checking the disk was there, so more than likely
>>> a mistake by me
>>>
>>>
>>>
>>>> On 24 October 2011 21:39, NeilBrown <neilb@suse.de> wrote:
>>>> On Mon, 24 Oct 2011 21:19:22 +0100 Michael Busby <michael.a.busby@gmail.com>
>>>> wrote:
>>>>
>>>>> Ok thanks, i have 1 small issue, when added the extra disk its been
>>>>> maked as spare, is this normal?
>>>>>
>>>>> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
>>>>> [raid4] [raid10]
>>>>> md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1]
>>>>>      7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18
>>>>> [6/5] [UUUUU_]
>>>>>      [>....................]  reshape =  3.0% (59244544/1953513984)
>>>>> finish=11122.8min speed=2837K/sec
>>>>
>>>> It looks like the extra drive was added after you started the grow.
>>>>
>>>> So it is still a spare.
>>>> Once the grow finishes you will have a singly-degraded RAID6.
>>>> Then it will immediately start recovering the missing device to the spare.
>>>>
>>>> Did you add the extra drive after starting the grow - or before??
>>>>
>>>> NeilBrown
>>>
>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>>> On 24 October 2011 21:14, NeilBrown <neilb@suse.de> wrote:
>>>>>> On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> should the speed be very slow when doing this progress, its a lot
>>>>>>> slower than a normal grow
>>>>>>
>>>>>> Yes.
>>>>>> The array is being reshaped in-place.  i.e. data is being read from part of
>>>>>> the array, rearranged, and written back to the same part of the array.
>>>>>> As you can imagine, this is risky - a crash will leave an inconsistent state.
>>>>>> Hence the backup file.  Everything in the array is first written to the
>>>>>> backup file, then back to the array.  So it is slow.
>>>>>>
>>>>>> A "normal" grow is writing to somewhere where there is no valid data, so it
>>>>>> doesn't need the backup.
>>>>>>
>>>>>> I do have a plan to make this faster.... but I have lots of plans and little
>>>>>> time.
>>>>>>
>>>>>> NeilBrown
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
>>>>>>>
>>>>>>>> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
>>>>>>>>> On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
>>>>>>>>> At the moment i have a raid5 setup with 5 disks, i am looking to add a
>>>>>>>>> 6th disk and change from raid 5 to raid 6
>>>>>>>>>
>>>>>>>>> having looked at Neil's site i have found the following command, and
>>>>>>>>> just want to double check this is still the recommend way of
>>>>>>>>> converting
>>>>>>>>>
>>>>>>>>> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
>>>>>>>>>
>>>>>>>>> also would i need to add the extra disk before or after the command?
>>>>>>>>>
>>>>>>>>> cheers
>>>>>>>>> --
>>>>>>>>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>>>>>>>>> the body of a message to majordomo@vger.kernel.org
>>>>>>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
>>>>>>>> partition it as required. Then add the drive to the array (I think
>>>>>>>> it'll become a spare?). Then you can grow it.
>>>>>>>>
>>>>>>>> Make sure you're using the latest mdadm tools available.
>>>>>>>>
>>>>>>>> Regards,
>>>>>>>> Mathias
>>>>>>> --
>>>>>>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>>>>>>> the body of a message to majordomo@vger.kernel.org
>>>>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Converting from Raid 5 to 6

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 6009 bytes --]

On Mon, 2 Dec 2013 15:07:57 +0000 Michael Busby <michael.a.busby@gmail.com>
wrote:

> Using -f seems to have worked just running e2fsck now

Excellent.

> 
> When running a command like mdadm --assemble -- force --verbose
> /dev/md0 /dev/sa[abcde] how important it the drive order?

Not at all.  The order is only important for --create.

NeilBrown

> 
> 
> Sent from my iPad
> 
> > On 2 Dec 2013, at 05:51 am, NeilBrown <neilb@suse.de> wrote:
> >
> > On Sat, 30 Nov 2013 22:13:58 +0000 Michael Busby <michael.a.busby@gmail.com>
> > wrote:
> >
> >> Sorry to bring up a old thread, last night i had a power cut and this
> >> morning when the power has come back i have tried to boot the server,
> >> but the raid will not assemble on using a live CD i have found that
> >> one of the disk is reporting "possibly out of date" is there any way
> >> to force this disk back in? the bigger problem i have is that my
> >> external caddie has died so i was running a degraded raid 6 but now it
> >> is only starting with 4 out of 6 devices. is there anyway to get this
> >> back?
> >
> > It's really hard to know what is possible without precise details.
> > Output of "mdadm -E" for each member device is always a good idea.
> > If you are having trouble assembling, then output of the assemble command
> > with -vv added never goes astray.
> > Have you tried adding "-f" to the assemble command.  Often helps and is
> > unlikely to hurt.
> >
> >>
> >> i have though about recreating the array using the --assume-clean
> >> option but not sure if that's a good idea
> >
> > Not a good idea except as a very last resort.
> >
> > NeilBrown
> >
> >
> >>
> >> any help will be much appreciated
> >>
> >>
> >>
> >>> On 24 October 2011 21:47, Michael Busby <michael.a.busby@gmail.com> wrote:
> >>>
> >>> I was sure i added the device before, but when rebooted the system it
> >>> has seemed to lose the extra drive and i had already restarted the
> >>> grow command with out checking the disk was there, so more than likely
> >>> a mistake by me
> >>>
> >>>
> >>>
> >>>> On 24 October 2011 21:39, NeilBrown <neilb@suse.de> wrote:
> >>>> On Mon, 24 Oct 2011 21:19:22 +0100 Michael Busby <michael.a.busby@gmail.com>
> >>>> wrote:
> >>>>
> >>>>> Ok thanks, i have 1 small issue, when added the extra disk its been
> >>>>> maked as spare, is this normal?
> >>>>>
> >>>>> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
> >>>>> [raid4] [raid10]
> >>>>> md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1]
> >>>>>      7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18
> >>>>> [6/5] [UUUUU_]
> >>>>>      [>....................]  reshape =  3.0% (59244544/1953513984)
> >>>>> finish=11122.8min speed=2837K/sec
> >>>>
> >>>> It looks like the extra drive was added after you started the grow.
> >>>>
> >>>> So it is still a spare.
> >>>> Once the grow finishes you will have a singly-degraded RAID6.
> >>>> Then it will immediately start recovering the missing device to the spare.
> >>>>
> >>>> Did you add the extra drive after starting the grow - or before??
> >>>>
> >>>> NeilBrown
> >>>
> >>>
> >>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>> On 24 October 2011 21:14, NeilBrown <neilb@suse.de> wrote:
> >>>>>> On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby <michael.a.busby@gmail.com>
> >>>>>> wrote:
> >>>>>>
> >>>>>>> should the speed be very slow when doing this progress, its a lot
> >>>>>>> slower than a normal grow
> >>>>>>
> >>>>>> Yes.
> >>>>>> The array is being reshaped in-place.  i.e. data is being read from part of
> >>>>>> the array, rearranged, and written back to the same part of the array.
> >>>>>> As you can imagine, this is risky - a crash will leave an inconsistent state.
> >>>>>> Hence the backup file.  Everything in the array is first written to the
> >>>>>> backup file, then back to the array.  So it is slow.
> >>>>>>
> >>>>>> A "normal" grow is writing to somewhere where there is no valid data, so it
> >>>>>> doesn't need the backup.
> >>>>>>
> >>>>>> I do have a plan to make this faster.... but I have lots of plans and little
> >>>>>> time.
> >>>>>>
> >>>>>> NeilBrown
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>
> >>>>>>> reshape =  1.2% (25006080/1953513984) finish=12481.8min speed=2574K/sec
> >>>>>>>
> >>>>>>>> On 24 October 2011 15:11, Mathias Burén <mathias.buren@gmail.com> wrote:
> >>>>>>>>> On 24 October 2011 14:11, Michael Busby <michael.a.busby@gmail.com> wrote:
> >>>>>>>>> At the moment i have a raid5 setup with 5 disks, i am looking to add a
> >>>>>>>>> 6th disk and change from raid 5 to raid 6
> >>>>>>>>>
> >>>>>>>>> having looked at Neil's site i have found the following command, and
> >>>>>>>>> just want to double check this is still the recommend way of
> >>>>>>>>> converting
> >>>>>>>>>
> >>>>>>>>> mdadm --grow /dev/md0 --level=6 --raid-disks=6 --backup-file=/home/md.backup
> >>>>>>>>>
> >>>>>>>>> also would i need to add the extra disk before or after the command?
> >>>>>>>>>
> >>>>>>>>> cheers
> >>>>>>>>> --
> >>>>>>>>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> >>>>>>>>> the body of a message to majordomo@vger.kernel.org
> >>>>>>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>>>>>>>
> >>>>>>>> Hi,
> >>>>>>>>
> >>>>>>>> I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive. Then
> >>>>>>>> partition it as required. Then add the drive to the array (I think
> >>>>>>>> it'll become a spare?). Then you can grow it.
> >>>>>>>>
> >>>>>>>> Make sure you're using the latest mdadm tools available.
> >>>>>>>>
> >>>>>>>> Regards,
> >>>>>>>> Mathias
> >>>>>>> --
> >>>>>>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> >>>>>>> the body of a message to majordomo@vger.kernel.org
> >>>>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >


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