Reshaping the length of devices
I am wondering... is it possible to reshape the length of the underlying devices with MD raid?
I mean like in the case one buys larger disks: after moving the raid partitions to the new disks half of them is still free. So one might want to extend the raid partitions to the end of the disks instead of creating another array in the free space.
I have searched the linux-raid mailing list history but I couldn't find this topic.
Thanks in advance
Quoted 13 lines · Asdo
From: Asdo <[email protected]>
Subject: Reshaping the length of devices
To: "linux-raid" <[email protected]>
Date: Friday, 12 March, 2010, 15:15
I am wondering... is it possible to
reshape the length of the underlying devices with MD raid?I mean like in the case one buys larger disks: after moving the raid partitions to the new disks half of them is still free. So one might want to extend the raid partitions to the end of the disks instead of creating another array in the free space.
Quoted 4 lines
I have searched the linux-raid mailing list history but I couldn't find this topic.
Thanks in advance
As long as the size of ALL underlying devices have increased you can --grow=MAX to the a multiple of the now smallest drive.
From:
http://linux.die.net/man/8/mdadm
This value can be set with --grow for RAID level 1/4/5/6. If the array was created with a size smaller than the currently active drives, the extra space can be accessed using --grow. The size can be given as max which means to choose the largest size that fits on all current drives.
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N: Jon Hardcastle
E: [email protected]
'Do not worry about tomorrow, for tomorrow will bring worries of its own.'
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I think it depends on how you migrate to the new disks. The best option would be to have one partition use all the space on the new (larger) disks, and replace a disk in the array with the new disk & wait for it to sync. Do the same for all disks.
You'll end up with a working array, where each disk has 1 partition but the total size of the array is only consuming half the capacity.
After that just use --growth and it'll expand the array to the max available capacity from the disks.
Quoted 17 lines · Asdo
I am wondering... is it possible to reshape the length of the underlying devices with MD raid?
I mean like in the case one buys larger disks: after moving the raid partitions to the new disks half of them is still free. So one might want to extend the raid partitions to the end of the disks instead of creating another array in the free space.
I have searched the linux-raid mailing list history but I couldn't find this topic.
Thanks in advance
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Signature · 5 lines
Majed B. -- 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 17 lines · Jon Hardcastle
Quoted 13 lines · Asdo
From: Asdo <[email protected]>
Subject: Reshaping the length of devices
To: "linux-raid" <[email protected]>
Date: Friday, 12 March, 2010, 15:15
I am wondering... is it possible to
reshape the length of the underlying devices with MD raid?I mean like in the case one buys larger disks: after moving the raid partitions to the new disks half of them is still free. So one might want to extend the raid partitions to the end of the disks instead of creating another array in the free space.
Quoted 6 lines
Quoted 4 lines
I have searched the linux-raid mailing list history but I couldn't find this topic.
Thanks in advance
As long as the size of ALL underlying devices have increased you can --grow=MAX to the a multiple of the now smallest drive.
Hmm, that reminds me I was meaning to ask - before I have to go to a customer's premises and try it - if I have a CentOS 5 system with 0.90 metadata and type fd partitions with RAID-5 over 3 discs, and I want to grow it by replacing the drives, if I dd small partitions onto larger ones and reboot, will the system recognise the RAID-5 - which now has its metadata somewhere in the middle of the paritions not at the end - so that I can then --grow?
Cheers,
John.
John, don't hijack the thread.
Post your question in a separate email.
Quoted 42 lines · John Robinson
Quoted 17 lines · Jon Hardcastle
Quoted 13 lines · Asdo
From: Asdo <[email protected]>
Subject: Reshaping the length of devices
To: "linux-raid" <[email protected]>
Date: Friday, 12 March, 2010, 15:15
I am wondering... is it possible to
reshape the length of the underlying devices with MD raid?I mean like in the case one buys larger disks: after moving the raid partitions to the new disks half of them is still free. So one might want to extend the raid partitions to the end of the disks instead of creating another array in the free space.
Quoted 7 lines
Quoted 4 lines
I have searched the linux-raid mailing list history but I couldn't find this topic.
Thanks in advance
As long as the size of ALL underlying devices have increased you can --grow=MAX to the a multiple of the now smallest drive.
Hmm, that reminds me I was meaning to ask - before I have to go to a customer's premises and try it - if I have a CentOS 5 system with 0.90 metadata and type fd partitions with RAID-5 over 3 discs, and I want to grow it by replacing the drives, if I dd small partitions onto larger ones and reboot, will the system recognise the RAID-5 - which now has its metadata somewhere in the middle of the paritions not at the end - so that I can then --grow?
Cheers,
John.
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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
Signature · 5 lines
Majed B. -- 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 3 lines · Majed B.
John, don't hijack the thread.
Post your question in a separate email.
Well, I didn't think I was wildly off-topic for the thread, but OK.
Cheers,
John.