not able to resize/grow RAID-1 (beyond 1 TB?)
Hi,
I have mdadm RAID-1 array which is 1 TB big.
I would like to increase it to ~3 TB, since this is what the new partition size is - however, mdadm doesn't want to do it and stays with the old size.
Here, mdadm -D output showing the array is 1024 GB:
# mdadm -D /dev/md2
/dev/md2:
Version : 1.2
Creation Time : Fri Jan 13 07:02:29 2012
Raid Level : raid1
Array Size : 1073740800 (1024.00 GiB 1099.51 GB)
Used Dev Size : 1073740800 (1024.00 GiB 1099.51 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent Update Time : Fri Jan 13 21:25:09 2012
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Name : rescue:2
UUID : 9fc28b3f:7b91d523:8aa20629:5f5bd029
Events : 6699
Number Major Minor RaidDevice State
0 8 3 0 active sync /dev/sda3
1 8 19 1 active sync /dev/sdb3
Here, we can see the partitions used by /dev/md2 are ~3 TB big:
# parted /dev/sda GNU Parted 2.3 Using /dev/sda Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) p Model: ATA ST3000DM001-9YN1 (scsi) Disk /dev/sda: 3001GB Sector size (logical/physical): 512B/4096B Partition Table: gpt
Number Start End Size File system Name Flags 5 1049kB 2097kB 1049kB bios_grub 1 2097kB 34.4GB 34.4GB raid 2 34.4GB 34.9GB 537MB raid 3 34.9GB 3001GB 2966GB raid
(parted) q
# parted /dev/sdb GNU Parted 2.3 Using /dev/sdb Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) p Model: ATA ST3000DM001-9YN1 (scsi) Disk /dev/sdb: 3001GB Sector size (logical/physical): 512B/4096B Partition Table: gpt
Number Start End Size File system Name Flags 5 1049kB 2097kB 1049kB bios_grub 1 2097kB 34.4GB 34.4GB raid 2 34.4GB 34.9GB 537MB raid 3 34.9GB 3001GB 2966GB raid
(parted) q
Now, let's try to grow - it stays unchanged at 1024 GB:
# mdadm --grow /dev/md2 --size=max mdadm: component size of /dev/md2 has been set to 1073740800K
What am I doing wrong here?
Signature · 2 lines
Tomasz Chmielewski http://wpkg.org
Quoted 8 lines · On 01/14/2012 09:26 PM, Stefan /*St0fF*/ Hübner wrote:
Hi Tomasz,
at first: if you had 1TB drives before, dd'ed them to the new 3TB drives and changed the partitioning scheme accordingly - that all looks OK. The weird thing here is that 1TB disks never had 1024GiB, but 931GiB. So the reshape has already happened to "the system's maximum".
I do suspect you have a 32bit system and mdadm is not the latest version?
No, the system was 64 bit from the very beginning; mdadm may not be the latest one, but is far from being obsoletes, too (Debian Squeeze).
The issue is actually solved now.
What I had to do was:
mdadm /dev/md2 -f /dev/sdb3
mdadm /dev/md2 -r /dev/sdb3
# not necessarily 10 MB needs cleaning, but it's a small number... dd if=/dev/zero of=/dev/sdb3 bs=1M count=10 mdadm /dev/md2 -a /dev/sdb3 # wait till it syncs, and do the same for /dev/sda3 reboot
If I did the same without dd if=/dev/zero, it somehow didn't want to work and /dev/md2 was still only 1 TB big. Unless I've messed up somewhere!
Signature · 8 lines
Tomasz Chmielewski http://wpkg.org -- 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