Add disks to RAID5 array

Add disks to RAID5 array

[robin-lists]

Hi,

I had intended to build a RAID5 array using 6 x 250GB drives. However, 3 of
6 drives have proven to be faulty and have been RMA'd.

I've successfully built the array using the remaining 3 x 250GB drives
(details below)

Now, when I get the other three disks back, how do I add them to this array
and increase the size of the array? Is this possible?

Thanks,

R.



[root@dude root]# mdadm --detail /dev/md5
/dev/md5:
        Version : 00.90.01
  Creation Time : Thu Jul 22 14:13:50 2004
     Raid Level : raid5
     Array Size : 487283200 (464.71 GiB 498.98 GB)
    Device Size : 243641600 (232.35 GiB 249.49 GB)
   Raid Devices : 3
  Total Devices : 3
Preferred Minor : 5
    Persistence : Superblock is persistent

    Update Time : Thu Jul 22 17:00:18 2004
          State : clean
 Active Devices : 3
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 128K

    Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       8       18        1      active sync   /dev/sdb2
       2       8       34        2      active sync   /dev/sdc2
           UUID : dde32a88:4b9bf7c1:1a634922:efbac4b0
         Events : 0.448136

--
http://robinbowes.com 

Re: Add disks to RAID5 array

[TJ Harrell]

Check out the "raidreconf" utility. It will grow RAID 5 arrays onto new
disks. It will not expand the partitions on the raid, though. For that
you'll need a utility like resize2fs.

----- Original Message ----- 
From: <robin-lists@robinbowes.com>
To: <linux-raid@vger.kernel.org>
Sent: Thursday, July 22, 2004 12:20 PM
Subject: Add disks to RAID5 array


> Hi,
>
> I had intended to build a RAID5 array using 6 x 250GB drives. However, 3
of
> 6 drives have proven to be faulty and have been RMA'd.
>
> I've successfully built the array using the remaining 3 x 250GB drives
> (details below)
>
> Now, when I get the other three disks back, how do I add them to this
array
> and increase the size of the array? Is this possible?
>
> Thanks,
>
> R.
>
>
>
> [root@dude root]# mdadm --detail /dev/md5
> /dev/md5:
>         Version : 00.90.01
>   Creation Time : Thu Jul 22 14:13:50 2004
>      Raid Level : raid5
>      Array Size : 487283200 (464.71 GiB 498.98 GB)
>     Device Size : 243641600 (232.35 GiB 249.49 GB)
>    Raid Devices : 3
>   Total Devices : 3
> Preferred Minor : 5
>     Persistence : Superblock is persistent
>
>     Update Time : Thu Jul 22 17:00:18 2004
>           State : clean
>  Active Devices : 3
> Working Devices : 3
>  Failed Devices : 0
>   Spare Devices : 0
>
>          Layout : left-symmetric
>      Chunk Size : 128K
>
>     Number   Major   Minor   RaidDevice State
>        0       8        2        0      active sync   /dev/sda2
>        1       8       18        1      active sync   /dev/sdb2
>        2       8       34        2      active sync   /dev/sdc2
>            UUID : dde32a88:4b9bf7c1:1a634922:efbac4b0
>          Events : 0.448136
>
> --
> http://robinbowes.com
>
> -
> 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: Add disks to RAID5 array

[Guy]

A tool called Raidreconf can do what you want.
I have never used it.
I don't know how much risk there is in data loss.
I would backup my data first!

Find it, read about it, and understand it.

Maybe someone else can comment on the risks?

Guy

-----Original Message-----
From: linux-raid-owner@vger.kernel.org
[mailto:linux-raid-owner@vger.kernel.org] On Behalf Of
robin-lists@robinbowes.com
Sent: Thursday, July 22, 2004 12:20 PM
To: linux-raid@vger.kernel.org
Subject: Add disks to RAID5 array

Hi,

I had intended to build a RAID5 array using 6 x 250GB drives. However, 3 of
6 drives have proven to be faulty and have been RMA'd.

I've successfully built the array using the remaining 3 x 250GB drives
(details below)

Now, when I get the other three disks back, how do I add them to this array
and increase the size of the array? Is this possible?

Thanks,

R.



[root@dude root]# mdadm --detail /dev/md5
/dev/md5:
        Version : 00.90.01
  Creation Time : Thu Jul 22 14:13:50 2004
     Raid Level : raid5
     Array Size : 487283200 (464.71 GiB 498.98 GB)
    Device Size : 243641600 (232.35 GiB 249.49 GB)
   Raid Devices : 3
  Total Devices : 3
Preferred Minor : 5
    Persistence : Superblock is persistent

    Update Time : Thu Jul 22 17:00:18 2004
          State : clean
 Active Devices : 3
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 128K

    Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       8       18        1      active sync   /dev/sdb2
       2       8       34        2      active sync   /dev/sdc2
           UUID : dde32a88:4b9bf7c1:1a634922:efbac4b0
         Events : 0.448136

--
http://robinbowes.com 

-
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: Add disks to RAID5 array

[TJ Harrell]

I've used raidreconf to convert from RAID 1 to RAID 5 and to grow RAID 5
arrays. I would recommend a UPS. If the power blips, the array will be lost.
Other then that, I've never had any trouble whatsoever with it. IMO,
resize2fs is more dangerous than using raidreconf. I have had resize2fs
corrupt file systems badly before. It's important to run fsck -f both before
and after resize2fs. It catches a lot of minor, fixable problems after the
resize2fs is run. Doing this, I have successfully grown RAID 5 arrays many
times without any trouble.

In any case, backing up is highly recommended if you value the data!

----- Original Message ----- 
From: "Guy" <bugzilla@watkins-home.com>
To: <robin-lists@robinbowes.com>; <linux-raid@vger.kernel.org>
Sent: Thursday, July 22, 2004 2:07 PM
Subject: RE: Add disks to RAID5 array


> A tool called Raidreconf can do what you want.
> I have never used it.
> I don't know how much risk there is in data loss.
> I would backup my data first!
>
> Find it, read about it, and understand it.
>
> Maybe someone else can comment on the risks?
>
> Guy

RE: Add disks to RAID5 array

[Robin Bowes]

> -----Original Message-----
> From: linux-raid-owner@vger.kernel.org 
> [mailto:linux-raid-owner@vger.kernel.org] On Behalf Of TJ Harrell
> Sent: 22 July 2004 18:33
> To: linux-raid@vger.kernel.org
> Subject: Re: Add disks to RAID5 array
> 
> I've used raidreconf to convert from RAID 1 to RAID 5 and to 
> grow RAID 5 arrays. I would recommend a UPS. If the power 
> blips, the array will be lost.
> Other then that, I've never had any trouble whatsoever with 
> it. IMO, resize2fs is more dangerous than using raidreconf. I 
> have had resize2fs corrupt file systems badly before. It's 
> important to run fsck -f both before and after resize2fs. It 
> catches a lot of minor, fixable problems after the resize2fs 
> is run. Doing this, I have successfully grown RAID 5 arrays 
> many times without any trouble.
> 
> In any case, backing up is highly recommended if you value the data!

TJ,

I didn't say, but I've been using mdadm to create/manage my RAID so far. Do
you know if it's possible to achieve this using just mdadm?

That actually prompts me to ask another question...which I'll save for
another thread!

R.
--
http://robinbowes.com