Hello everyone. In anticipation of the launch of a new group of the Linux Administrator course , we are publishing useful material written by our student, as well as the course mentor, REG.RU corporate product technical support specialist Roman Travin.
This article will discuss 2 cases of replacing disks and transferring information to new disks of a larger volume with further expansion of the array and file system. The first case will concern the replacement of disks with the same MBR / MBR or GPT / GPT markup, the second case will concern the replacement of disks with MBR marking by disks with a capacity of more than 2 TB, on which GPT markup with the biosboot partition will be required. In both cases, the disks to which we transfer data are already installed on the server. The file system used for the root partition is ext4.
Case 1: Replacing smaller drives with larger drives (up to 2TB)
Task: Replace current drives with larger drives (up to 2 TB) with information transfer. In this case, we have 2 x 240 GB SSD (RAID-1) disks with the installed system and 2 x 1 TB SATA disks on which you need to transfer the system.Consider the current disk layout.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sda2 8:2 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdb2 8:18 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdc 8:32 0 931,5G 0 disk
sdd 8:48 0 931,5G 0 disk
Check the current file system space used.[root@localhost ~]
% C
devtmpfs 32G 0 32G 0% /dev
tmpfs 32G 0 32G 0% /dev/shm
tmpfs 32G 9,6M 32G 1% /run
tmpfs 32G 0 32G 0% /sys/fs/cgroup
/dev/mapper/vg0-root 204G 1,3G 192G 1% /
/dev/md126 1007M 120M 837M 13% /boot
tmpfs 6,3G 0 6,3G 0% /run/user/0
The file system size before replacing the disks is 204 GB, 2 md126 program arrays are used, which is mounted in /bootand md127which is used as physical volume for the VG group vg0 .1. Removing disk partitions from arrays
Check the state of the array[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sda1[0] sdb1[1]
1047552 blocks super 1.2 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sda2[0] sdb2[1]
233206784 blocks super 1.2 [2/2] [UU]
bitmap: 0/2 pages [0KB], 65536KB chunk
unused devices: <none>
The system uses 2 arrays: md126(mount point /boot) - consists of a partition /dev/sda1and /dev/sdb1, md127(LVM for swap and the root of the file system) - consists of /dev/sda2and /dev/sdb2.We mark the partitions of the first disk that are used in each array as bad.mdadm /dev/md126 --fail /dev/sda1
mdadm /dev/md127 --fail /dev/sda2
We remove sections of the block device / dev / sda from arrays.mdadm /dev/md126 --remove /dev/sda1
mdadm /dev/md127 --remove /dev/sda2
After we removed the disk from the array, information about block devices will look like this.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdb2 8:18 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdc 8:32 0 931,5G 0 disk
sdd 8:48 0 931,5G 0 disk
The state of arrays after removing disks.[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sdb1[1]
1047552 blocks super 1.2 [2/1] [_U]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sdb2[1]
233206784 blocks super 1.2 [2/1] [_U]
bitmap: 1/2 pages [4KB], 65536KB chunk
unused devices: <none>
2. Copying the partition table to a new disk
You can check the partition table used on the disk with the following command.fdisk -l /dev/sdb | grep 'Disk label type'
The output for the MBR will be:Disk label type: dos
for GPT:Disk label type: gpt
Copy markup table for MBR:
sfdisk -d /dev/sdb | sfdisk /dev/sdc
In this command , the disk from which the markup is copied is indicated first , the second is where to copy. NOTE : For GPT first specified disk on which to copy the layout, the second disk drive is specified from which to copy the markup. If you mix up the disks, then the initially healthy markup will be overwritten and destroyed.
Copying the markup table for the GPT:
sgdisk -R /dev/sd /dev/sdb
Next, assign a random UUID to the disk (for GPT).
sgdisk -G /dev/sdc
After the command is executed, partitions should appear on the disk /dev/sdc.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdb2 8:18 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
└─sdc2 8:34 0 222,5G 0 part
sdd 8:48 0 931,5G 0 disk
If after the performed action the partitions in the system on the disk are /dev/sdcnot defined, then we execute the command to re-read the partition table.sfdisk -R /dev/sdc
If the current disks use the MBR table and the information needs to be transferred to disks larger than 2 TB, then new disks will need to manually create GPT markup using the biosboot partition. This case will be considered in part 2 of this article.3. Adding partitions of the new disk to the array
Add disk partitions to the corresponding arrays.mdadm /dev/md126 --add /dev/sdc1
mdadm /dev/md127 --add /dev/sdc2
Check that sections have been added.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdb2 8:18 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc2 8:34 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 931,5G 0 disk
After that we wait for the synchronization of arrays.[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sdc1[2] sdb1[1]
1047552 blocks super 1.2 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sdc2[2] sdb2[1]
233206784 blocks super 1.2 [2/1] [_U]
[==>..................] recovery = 10.6% (24859136/233206784) finish=29.3min speed=118119K/sec
bitmap: 2/2 pages [8KB], 65536KB chunk
unused devices: <none>
You can continuously monitor the synchronization process using the utility watch.watch -n 2 cat /proc/mdstat
The parameter -nindicates at what intervals in seconds it is necessary to execute a command to check progress.Repeat steps 1 - 3 for the next replacement drive.We mark the partitions of the second disk, which are used in each array, as bad.mdadm /dev/md126 --fail /dev/sdb1
mdadm /dev/md127 --fail /dev/sdb2
We delete sections of the block device /dev/sdbfrom arrays.mdadm /dev/md126 --remove /dev/sdb1
mdadm /dev/md127 --remove /dev/sdb2
After we removed the disk from the array, information about block devices will look like this.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 222,5G 0 part
sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc2 8:34 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 931,5G 0 disk
The state of arrays after removing disks.[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sdc1[2]
1047552 blocks super 1.2 [2/1] [U_]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sdc2[2]
233206784 blocks super 1.2 [2/1] [U_]
bitmap: 1/2 pages [4KB], 65536KB chunk
unused devices: <none>
Copy the MBR markup table from disk /dev/sd to disk /dev/sdd.sfdisk -d /dev/sd | sfdisk /dev/sdd
After the command is executed, partitions should appear on the disk /dev/sdd.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 222,5G 0 part
sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc2 8:34 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 931,5G 0 disk
├─sdd1 8:49 0 1G 0 part
└─sdd2 8:50 0 222,5G 0 part
Add disk partitions to arrays.mdadm /dev/md126 --add /dev/sdd1
mdadm /dev/md127 --add /dev/sdd2
Check that sections have been added.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 222,5G 0 part
sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc2 8:34 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 931,5G 0 disk
├─sdd1 8:49 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdd2 8:50 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
After that we wait for the synchronization of arrays.[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sdd1[3] sdc1[2]
1047552 blocks super 1.2 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sdd2[3] sdc2[2]
233206784 blocks super 1.2 [2/1] [U_]
[>....................] recovery = 0.5% (1200000/233206784) finish=35.4min speed=109090K/sec
bitmap: 2/2 pages [8KB], 65536KB chunk
unused devices: <none>
5. Install GRUB on new drives
For CentOS:grub2-install /dev/sdX
For Debian / Ubuntu:grub-install /dev/sdX
where Xis the letter of the block device. In this case, install GRUB on /dev/sdcand /dev/sdd.6. Extension of the file system (ext4) of the root partition
On new disks /dev/sdcand /dev/sddavailable 931.5 GB. Due to the fact that the partition table is a smaller volume is copied from CDs, on the sections /dev/sdc2and /dev/sdd2are available 222.5 GB.sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc2 8:34 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 931,5G 0 disk
├─sdd1 8:49 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdd2 8:50 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
It is necessary:- Extend section 2 on each drive,
- Extend the md127 array,
- Expand PV (physical volume),
- Extend LV (logical-volume) vg0-root,
- Extend the file system.
Using the parted utility , we expand the section /dev/sdc2to the maximum value. We execute command parted /dev/sdc(1) and view the current partition table with command p(2).
As you can see, the end of section 2 ends with 240 GB. Let's expand the section with the command resizepart 2, where 2 is the section number (3). We indicate the value in digital format, for example 1000 GB, or we use the indication of the disk share - 100%. Again we check that the section has a new size (4).Repeat the above steps for the disk /dev/sdd. After the expansion of the sections, /dev/sdc2they /dev/sdd2became equal to 930.5 GB.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 222,5G 0 part
sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc2 8:34 0 930,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 931,5G 0 disk
├─sdd1 8:49 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdd2 8:50 0 930,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
After that, we expand the md127 array to the maximum.mdadm --grow /dev/md127 --size=max
Check that the array has expanded. Now its size has become 930.4 GB.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 222,5G 0 part
sdc 8:32 0 931,5G 0 disk
├─sdc1 8:33 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc2 8:34 0 930,5G 0 part
└─md127 9:127 0 930,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 931,5G 0 disk
├─sdd1 8:49 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdd2 8:50 0 930,5G 0 part
└─md127 9:127 0 930,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
We perform the expansion of physical volume . Before expansion, check the current state of PV.[root@localhost ~]
PV /dev/md127 VG vg0 lvm2 [222,40 GiB / 0 free]
Total: 1 [222,40 GiB] / in use: 1 [222,40 GiB] / in no VG: 0 [0 ]
As you can see, PV /dev/md127uses 222.4 GB of space.Expand PV with the following command.pvresize /dev/md127
Check the result of the PV extension.[root@localhost ~]
PV /dev/md127 VG vg0 lvm2 [930,38 GiB / 707,98 GiB free]
Total: 1 [930,38 GiB] / in use: 1 [930,38 GiB] / in no VG: 0 [0 ]
Expanding logical volume . Before the extension, check the current status of LV (1).[root@localhost ~]
ACTIVE '/dev/vg0/swap' [<16,00 GiB] inherit
ACTIVE '/dev/vg0/root' [<206,41 GiB] inherit
LV /dev/vg0/rootuses 206.41 GB.We expand LV with the following command (2).lvextend -l +100%FREE /dev/mapper/vg0-root
Check the performed action (3).[root@localhost ~]
ACTIVE '/dev/vg0/swap' [<16,00 GiB] inherit
ACTIVE '/dev/vg0/root' [<914,39 GiB] inherit
As you can see, after expanding LV, the amount of disk space occupied became 914.39 GB.
LV volume has increased (4), but the file system still occupies 204 GB (5).1. Perform the file system extension.resize2fs /dev/mapper/vg0-root
Check after the executed command the size of the file system.[root@localhost ~]
% C
devtmpfs 32G 0 32G 0% /dev
tmpfs 32G 0 32G 0% /dev/shm
tmpfs 32G 9,5M 32G 1% /run
tmpfs 32G 0 32G 0% /sys/fs/cgroup
/dev/mapper/vg0-root 900G 1,3G 860G 1% /
/dev/md126 1007M 120M 837M 13% /boot
tmpfs 6,3G 0 6,3G 0% /run/user/0
The size of the root file system will increase to 900 GB. After completing the steps, you can remove the old discs.Case 2: Replacing smaller drives with larger drives (more than 2TB)
Task: Replace current disks with larger disks (2 x 3TB) with saving information. In this case, we have 2 x 240 GB SSD (RAID-1) disks with the installed system and 2 x 3 TB SATA disks to which you need to transfer the system. Current drives use the MBR partition table. Since new disks have a capacity of more than 2 TB, they will need to use the GPT table, since MBR cannot work with disks larger than 2TB.View the current disk layout.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sda2 8:2 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdb2 8:18 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdc 8:32 0 2,7T 0 disk
sdd 8:48 0 2,7T 0 disk
Check the partition table used on the disk /dev/sda.[root@localhost ~]
Disk label type: dos
The disk /dev/sdbuses a similar partition table. Check the used disk space in the system.[root@localhost ~]
% C
devtmpfs 16G 0 16G 0% /dev
tmpfs 16G 0 16G 0% /dev/shm
tmpfs 16G 9,5M 16G 1% /run
tmpfs 16G 0 16G 0% /sys/fs/cgroup
/dev/mapper/vg0-root 204G 1,3G 192G 1% /
/dev/md126 1007M 120M 837M 13% /boot
tmpfs 3,2G 0 3,2G 0% /run/user/0
As you can see, the root of the file system is 204 GB. Check the current state of the software RAID.1. Install GPT partition table and disk partitioning
Check disk layout by sector.[root@localhost ~]
: ATA KINGSTON SVP200S (scsi)
/dev/sda: 240GB
(./.): 512B/512B
: msdos
Disk Flags:
1 1049kB 1076MB 1075MB primary , raid
2 1076MB 240GB 239GB primary raid
On the new 3TB drive, we will need to create 3 partitions:- CATEGORY
bios_grub2MiB GPT size for compatibility with the BIOS, - The partition for the RAID array to be mounted on
/boot. - The partition for the RAID array, on which will be LV root and LV swap .
Install the parted utility with the command yum install -y parted(for CentOS), apt install -y parted(for Debian / Ubuntu).Using parted, execute the following commands to partition the disk.We execute the command parted /dev/sdcand go into edit mode for disk layout.Create a GPT partition table.(parted) mktable gpt
We create 1 section bios_grubsection and set a flag for it.(parted) mkpart primary 1MiB 3MiB
(parted) set 1 bios_grub on
Create a 2 section and set a flag for it. The partition will use as a block for the RAID array and mount it in /boot.(parted) mkpart primary ext2 3MiB 1028MiB
(parted) set 2 boot on
We create a 3 section, which will also be used as an array block in which there will be LVM.(parted) mkpart primary 1028MiB 100%
In this case, setting the flag is not necessary, but if necessary, it is possible to set it with the following command.(parted) set 3 raid on
Check the created table.(parted) p
: ATA TOSHIBA DT01ACA3 (scsi)
/dev/sdc: 3001GB
(./.): 512B/4096B
: gpt
Disk Flags:
1 1049kB 3146kB 2097kB primary bios_grub
2 3146kB 1077MB 1074MB primary
3 1077MB 3001GB 3000GB primary
Assign the drive a new random GUID.sgdisk -G /dev/sdd
2. Removing partitions of the first disk from arrays
Check the state of the array[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sda1[0] sdb1[1]
1047552 blocks super 1.2 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sda2[0] sdb2[1]
233206784 blocks super 1.2 [2/2] [UU]
bitmap: 0/2 pages [0KB], 65536KB chunk
unused devices: <none>
The system uses 2 arrays: md126 (mount point / boot) - consists of /dev/sda1and /dev/sdb1, md127(LVM for swapand the root of the file system) - consists of /dev/sda2and /dev/sdb2.We mark the partitions of the first disk that are used in each array as bad.mdadm /dev/md126 --fail /dev/sda1
mdadm /dev/md127 --fail /dev/sda2
We delete sections of the block device /dev/sdafrom arrays.mdadm /dev/md126 --remove /dev/sda1
mdadm /dev/md127 --remove /dev/sda2
Check the state of the array after removing the disk.[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sdb1[1]
1047552 blocks super 1.2 [2/1] [_U]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sdb2[1]
233206784 blocks super 1.2 [2/1] [_U]
bitmap: 2/2 pages [8KB], 65536KB chunk
unused devices: <none>
3. Adding partitions of the new disk to the array
The next step is to add the partitions of the new disk to the arrays for synchronization. We look at the current state of the disk layout.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdb2 8:18 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdc 8:32 0 2,7T 0 disk
├─sdc1 8:33 0 2M 0 part
├─sdc2 8:34 0 1G 0 part
└─sdc3 8:35 0 2,7T 0 part
sdd 8:48 0 2,7T 0 disk
A section /dev/sdc1is a bios_grubsection and is not involved in creating arrays. In arrays, only /dev/sdc2and will be involved /dev/sdc3. Add these sections to the corresponding arrays.mdadm /dev/md126 --add /dev/sdc2
mdadm /dev/md127 --add /dev/sdc3
Then we wait for the synchronization of the array.[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sdc2[2] sdb1[1]
1047552 blocks super 1.2 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md127 : active raid1 sdc3[2] sdb2[1]
233206784 blocks super 1.2 [2/1] [_U]
[>....................] recovery = 0.2% (619904/233206784) finish=31.2min speed=123980K/sec
bitmap: 2/2 pages [8KB], 65536KB chunk
unused devices: <none>
Partitioning disks after adding partitions to an array.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdb2 8:18 0 222,5G 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdc 8:32 0 2,7T 0 disk
├─sdc1 8:33 0 2M 0 part
├─sdc2 8:34 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc3 8:35 0 2,7T 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 2,7T 0 disk
4. Removing partitions of the second disk from arrays
We mark the partitions of the second disk, which are used in each array, as bad.mdadm /dev/md126 --fail /dev/sdb1
mdadm /dev/md127 --fail /dev/sdb2
We delete sections of the block device /dev/sdafrom arrays.mdadm /dev/md126 --remove /dev/sdb1
mdadm /dev/md127 --remove /dev/sdb2
5. Copy the GPT markup table and synchronize the array
To copy the GPT markup table, we will use the utility sgdiskthat is included in the package for working with disk partitions and the GPT table gdisk.Installation gdiskfor CentOS:yum install -y gdisk
Installation gdiskfor Debian / Ubuntu:apt install -y gdisk
ATTENTION : For GPT , the disk to which the markup is copied is first indicated , the second disk is the disk from which the markup is copied. If you mix up the disks, then the initially healthy markup will be overwritten and destroyed.
Copy the GPT markup table.sgdisk -R /dev/sdd /dev/sdc
Partitioning disks after transferring a table to disk /dev/sdd.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 222,5G 0 part
sdc 8:32 0 2,7T 0 disk
├─sdc1 8:33 0 2M 0 part
├─sdc2 8:34 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc3 8:35 0 2,7T 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 2,7T 0 disk
├─sdd1 8:49 0 2M 0 part
├─sdd2 8:50 0 1G 0 part
└─sdd3 8:51 0 2,7T 0 part
Next, we add each of the partitions participating in the software RAID arrays.mdadm /dev/md126 --add /dev/sdd2
mdadm /dev/md127 --add /dev/sdd3
We are waiting for the synchronization of the array.[root@localhost ~]
Personalities : [raid1]
md126 : active raid1 sdd2[3] sdc2[2]
1047552 blocks super 1.2 [2/2] [UU]
bitmap: 1/1 pages [4KB], 65536KB chunk
md127 : active raid1 sdd3[3] sdc3[2]
233206784 blocks super 1.2 [2/1] [U_]
[>....................] recovery = 0.0% (148224/233206784) finish=26.2min speed=148224K/sec
bitmap: 2/2 pages [8KB], 65536KB chunk
unused devices: <none>
After copying the GPT markup to a second new disk, the markup will look like this.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 222,5G 0 part
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 222,5G 0 part
sdc 8:32 0 2,7T 0 disk
├─sdc1 8:33 0 2M 0 part
├─sdc2 8:34 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdc3 8:35 0 2,7T 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 2,7T 0 disk
├─sdd1 8:49 0 2M 0 part
├─sdd2 8:50 0 1G 0 part
│ └─md126 9:126 0 1023M 0 raid1 /boot
└─sdd3 8:51 0 2,7T 0 part
└─md127 9:127 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
Next, install GRUB on the new drives.Installation for CentOS:grub2-install /dev/sdX
Installation for Debian / Ubuntu:grub-install /dev/sdX
where Xis the drive letter, in our case, the drives /dev/sdcand /dev/sdd.Updating the information about the array.For CentOS:mdadm --detail --scan --verbose > /etc/mdadm.conf
For Debian / Ubuntu:echo "DEVICE partitions" > /etc/mdadm/mdadm.conf
mdadm --detail --scan --verbose | awk '/ARRAY/ {print}' >> /etc/mdadm/mdadm.conf
Update image initrd:For CentOS:dracut -f -v --regenerate-all
For Debian / Ubuntu:update-initramfs -u -k all
Updating the GRUB configuration.For CentOS:grub2-mkconfig -o /boot/grub2/grub.cfg
For Debian / Ubuntu:update-grub
After the completed steps, the old discs can be removed.6. Extension of the file system (ext4) of the root partition
Partitioning disks before expanding the file system after moving the system to 2 x 3TB (RAID-1) disks.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
sdb 8:16 0 223,6G 0 disk
sdc 8:32 0 2,7T 0 disk
├─sdc1 8:33 0 2M 0 part
├─sdc2 8:34 0 1G 0 part
│ └─md127 9:127 0 1023M 0 raid1 /boot
└─sdc3 8:35 0 2,7T 0 part
└─md126 9:126 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 2,7T 0 disk
├─sdd1 8:49 0 2M 0 part
├─sdd2 8:50 0 1G 0 part
│ └─md127 9:127 0 1023M 0 raid1 /boot
└─sdd3 8:51 0 2,7T 0 part
└─md126 9:126 0 222,4G 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
Now sections /dev/sdc3and /dev/sdd3occupy 2.7 TB. Since we created a new partitioning of disks with a GPT table, the size of the 3 partitions was immediately set to the maximum possible disk space, in this case we do not need to expand the partition.It is necessary:- Extend the md126 array,
- Expand PV (physical volume),
- Extend LV (logical-volume) vg0-root,
- Extend the file system.
1. Expand the array md126to the maximum.mdadm --grow /dev/md126 --size=max
After expanding the array, the md126size of the occupied space increased to 2.7 TB.[root@localhost ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 223,6G 0 disk
sdb 8:16 0 223,6G 0 disk
sdc 8:32 0 2,7T 0 disk
├─sdc1 8:33 0 2M 0 part
├─sdc2 8:34 0 1G 0 part
│ └─md127 9:127 0 1023M 0 raid1 /boot
└─sdc3 8:35 0 2,7T 0 part
└─md126 9:126 0 2,7T 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
sdd 8:48 0 2,7T 0 disk
├─sdd1 8:49 0 2M 0 part
├─sdd2 8:50 0 1G 0 part
│ └─md127 9:127 0 1023M 0 raid1 /boot
└─sdd3 8:51 0 2,7T 0 part
└─md126 9:126 0 2,7T 0 raid1
├─vg0-root 253:0 0 206,4G 0 lvm /
└─vg0-swap 253:1 0 16G 0 lvm [SWAP]
Expanding physical volume .Before expansion, we check the current value of the occupied space PV / dev/md126.[root@localhost ~]
PV VG Fmt Attr PSize PFree
/dev/md126 vg0 lvm2 a-- 222,40g 0
Expand PV with the following command.pvresize /dev/md126
Check the completed action.[root@localhost ~]
PV VG Fmt Attr PSize PFree
/dev/md126 vg0 lvm2 a-- <2,73t 2,51t
Expanding class logical volume vg0-root .After expanding PV, we check the occupied space of VG.[root@localhost ~]
VG
vg0 1 2 0 wz--n- <2,73t 2,51t
Check the space occupied by LV.[root@localhost ~]
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root vg0 -wi-ao---- <206,41g
swap vg0 -wi-ao---- <16,00g
The vg0-root volume takes up 206.41 GB.Expand LV to maximum disk space.lvextend -l +100%FREE /dev/mapper/vg0-root
Checking the LV space after expansion.[root@localhost ~]
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root vg0 -wi-ao---- 2,71t
swap vg0 -wi-ao---- <16,00g
Extending the file system (ext4).Check the current file system size.[root@localhost ~]
% C
devtmpfs 16G 0 16G 0% /dev
tmpfs 16G 0 16G 0% /dev/shm
tmpfs 16G 9,6M 16G 1% /run
tmpfs 16G 0 16G 0% /sys/fs/cgroup
/dev/mapper/vg0-root 204G 1,4G 192G 1% /
/dev/md127 1007M 141M 816M 15% /boot
tmpfs 3,2G 0 3,2G 0% /run/user/0
The / dev / mapper / vg0-root volume takes up 204 GB after the LV extension.Expanding the file system.resize2fs /dev/mapper/vg0-root
Check the size of the file system after its expansion.[root@localhost ~]
% C
devtmpfs 16G 0 16G 0% /dev
tmpfs 16G 0 16G 0% /dev/shm
tmpfs 16G 9,6M 16G 1% /run
tmpfs 16G 0 16G 0% /sys/fs/cgroup
/dev/mapper/vg0-root 2,7T 1,4G 2,6T 1% /
/dev/md127 1007M 141M 816M 15% /boot
tmpfs 3,2G 0 3,2G 0% /run/user/0
The file system size is increased by the entire volume of the volume.