How to increase size of RAID1 in Linux !

in linux •  7 years ago  (edited)

How to increase size of RAID1 in Linux !

This summer I had to raise a raid partition from 1 TB to 2 TB.
I found some information, put link down.
This video explain how to increase size:

A good start for information:
https://www.howtoforge.com/how-to-resize-raid-partitions-shrink-and-grow-software-raid-p2
https://raid.wiki.kernel.org/index.php/A_guide_to_mdadm

I will show my steps:
Details

[root@dc ~]# mdadm --detail /dev/md2
/dev/md2:
Version : 1.1
Creation Time : Wed Jul 16 16:28:06 2014
Raid Level : raid1
Array Size : 972009280 (926.98 GiB 995.34 GB)
Used Dev Size : 972009280 (926.98 GiB 995.34 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Wed Jul 19 17:15:01 2017
      State : active

Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

       Name : serverp0.probiting.ro:2
       UUID : 20c27ff9:81cb1db1:91f3d123:77844d9c
     Events : 82177

Number   Major   Minor   RaidDevice State
   3       8       19        0      active sync   /dev/sdb3
   2       8        3        1      active sync   /dev/sda3

Partition /dev/sda3
<co[root@dc ~]# fdisk -l /dev/sda3

Disk /dev/sda3: 995.5 GB, 995471917056 bytes
255 heads, 63 sectors/track, 121025 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0xfffefffede>

Partition /dev/sdb3
[root@dc ~]# fdisk -l /dev/sdb3

Disk /dev/sdb3: 995.5 GB, 995471917056 bytes
255 heads, 63 sectors/track, 121025 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0xfffefffe

Fist step: fail one partition and remove, afther this grow partition.
[root@dc ~]# mdadm --manage /dev/md2 --fail /dev/sdb3
[root@dc ~]# mdadm --manage /dev/md2 --remove /dev/sdb3

Result:

[root@dc ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda1[2] sdb1[3]
524224 blocks super 1.0 [2/2] [UU]

md2 : active raid1 sda3[2]
972009280 blocks super 1.1 [2/1] [_U]
bitmap: 5/8 pages [20KB], 65536KB chunk

md1 : active raid1 sdb2[3] sda2[2]
4093888 blocks super 1.1 [2/2] [UU]

Remove raid block
[root@dc ~]# mdadm --zero-superblock /dev/sdb3
Now change size on /dev/sdb3
[root@dc ~]# fdisk /dev/sdb

The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').

Command (m for help): p

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 66 524288 fd Linux raid autodetect
Partition 1 does not end on cylinder boundary.
/dev/sdb2 66 576 4096000 fd Linux raid autodetect
Partition 2 does not end on cylinder boundary.
/dev/sdb3 576 121602 972140544 fd Linux raid autodetect

Command (m for help): d
Partition number (1-4): 3

Command (m for help): p

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 66 524288 fd Linux raid autodetect
Partition 1 does not end on cylinder boundary.
/dev/sdb2 66 576 4096000 fd Linux raid autodetect
Partition 2 does not end on cylinder boundary.

Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (576-243201, default 576):
Using default value 576
Last cylinder, +cylinders or +size{K,M,G} (576-243201, default 243201):
Using default value 243201

Command (m for help): p

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 66 524288 fd Linux raid autodetect
Partition 1 does not end on cylinder boundary.
/dev/sdb2 66 576 4096000 fd Linux raid autodetect
Partition 2 does not end on cylinder boundary.
/dev/sdb3 576 243201 1948890720+ 83 Linux

Command (m for help): t
Partition number (1-4): 3
Hex code (type L to list codes): fd
Changed system type of partition 3 to fd (Linux raid autodetect)

Command (m for help): p

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 66 524288 fd Linux raid autodetect
Partition 1 does not end on cylinder boundary.
/dev/sdb2 66 576 4096000 fd Linux raid autodetect
Partition 2 does not end on cylinder boundary.
/dev/sdb3 576 243201 1948890720+ fd Linux raid autodetect

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

Now add new raid device.
[root@dc ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda1[2] sdb1[3]
524224 blocks super 1.0 [2/2] [UU]

md2 : active raid1 sda3[2]
972009280 blocks super 1.1 [2/1] [_U]
bitmap: 5/8 pages [20KB], 65536KB chunk

md1 : active raid1 sdb2[3] sda2[2]
4093888 blocks super 1.1 [2/2] [UU]

[root@dc ~]# mdadm -a /dev/md2 /dev/sdb3
mdadm: added /dev/sdb3
[root@dc ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda1[2] sdb1[3]
524224 blocks super 1.0 [2/2] [UU]

md2 : active raid1 sdb3[3] sda3[2]
972009280 blocks super 1.1 [2/1] [_U]
[>....................] recovery = 0.0% (295168/972009280) finish=109.7min speed=147584K/sec
bitmap: 5/8 pages [20KB], 65536KB chunk

md1 : active raid1 sdb2[3] sda2[2]
4093888 blocks super 1.1 [2/2] [UU]

We wait until the next day when it ends in sync.

Day 2. We do the same with the other hard drive, /dev/sda3 but first we restart!

Warning After you change your hard drive and increase partitions you may have problems with grub because it changes the hardships.

I will put a short video with my steps în other post !


@luciancovaci
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Created on 20170918 at 10:52 EET

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