Adding the new drives to the RAID array
This section covers the steps required to add the new drives to the RAID array.
Ensure that the set of eight (8) drives is properly installed according to the Installing the drives section.
Procedure performed by: Customer or field service
To add the newly installed drives to the RAID array, follow these steps:
- Create the RAID5 device for the eight drives:
#/usr/share/tacp/lenovo/add_disks_lenovo.py
Following is an example output:
all disks are attached correctly to this controller.
Raid device created /dev/md123
Congratulations. You have successfully created the raid device
Please run the following command to continue: mdadm --grow /dev/md/md50 --raid-device=2 --add /dev/md123
SuccessThe script provides a -verbose option if you want to know details of how the RAID5 device is created.
- Grow the RAID50 device
mdadm --grow /dev/md/md50 --raid-device=2 --add /dev/md123
Following is an example output:
mdadm: level of /dev/md/md50 changed to raid4
mdadm: added /dev/md123NoteThis step is not scripted because this may take up to a few hours depending on how much data is stored in the RAID array.
- Check the RAID rebuild status:
cat /proc/mdstat
Following is an example output:
Personalities : [raid1] [raid6] [raid5] [raid4] [raid0]
md123 : active raid5 dm-22[7](S) dm-21[6] dm-20[5] dm-19[4] dm-18[3] dm-17[2] dm-16[1] dm-15[0]
4657379328 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 1/6 pages [4KB], 65536KB chunk
md124 : active raid4 md123[2] md125[0]
4657247232 blocks super 1.2 level 4, 512k chunk, algorithm 5 [3/2] [U__]
[>....................] reshape = 1.3% (62142976/4657247232) finish=424.9min speed=180210K/sec
md125 : active raid5 dm-7[7](S) dm-6[6] dm-5[5] dm-4[4] dm-3[3] dm-2[2] dm-1[1] dm-0[0]
4657379328 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 1/6 pages [4KB], 65536KB chunk
md126 : active raid1 sda[1] sdb[0]
118778880 blocks super external:/md127/0 [2/2] [UU]
md127 : inactive sdb[1](S) sda[0](S)
6306 blocks super external:imsm
unused devices: <none> - Check and calculate the completion time of the process.
As displayed in the example output from the previous step, the reshape process has a completion time of 424.9 minutes (finish=424.9min). In hours, this is a little over seven (7) hours (424.9 minutes / 60 = 7.08 hours).
- Wait until the completion time is up (in this example, more than seven (7) hours), and then check that the process has indeed finished:
cat /proc/mdstat
Following is an example output:
Personalities : [raid1] [raid6] [raid5] [raid4] [raid0]
md123 : active raid5 dm-22[7](S) dm-21[6] dm-20[5] dm-19[4] dm-18[3] dm-17[2] dm-16[1] dm-15[0]
4657379328 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 0/6 pages [0KB], 65536KB chunk
md124 : active raid0 md123[2] md125[0]
9314494464 blocks super 1.2 512k chunks
md125 : active raid5 dm-7[7](S) dm-6[6] dm-5[5] dm-4[4] dm-3[3] dm-2[2] dm-1[1] dm-0[0]
4657379328 blocks super 1.2 level 5, 16k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 0/6 pages [0KB], 65536KB chunk
md126 : active raid1 sda[1] sdb[0]
118778880 blocks super external:/md127/0 [2/2] [UU]
md127 : inactive sdb[1](S) sda[0](S)
6306 blocks super external:imsm
unused devices: <none> - Calculate new size of the RAID50 device:
nvme list
Following is an example output:
Node SN Namespace Usage Format FW Rev
---------------- ------------------ ... --------- ------------------------- -------------- --------
/dev/nvme0n1 S3HCNX0JC02194 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme10n1 S3HCNX0K100055 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme11n1 S3HCNX0K100061 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme12n1 S3HCNX0K100046 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme13n1 S3HCNX0K100092 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme14n1 S3HCNX0K100076 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme15n1 S3HCNX0K100015 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme1n1 S3HCNX0JC02193 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme2n1 S3HCNX0JC02233 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme3n1 S3HCNX0JC02191 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme4n1 S3HCNX0JC02189 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme5n1 S3HCNX0JC02198 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme6n1 S3HCNX0JC02188 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme7n1 S3HCNX0JC02195 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme8n1 S3HCNX0K100085 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3Q
/dev/nvme9n1 S3HCNX0K100072 1 795.00 GB / 795.00 GB 512 B + 0 B GPNA9B3QIn the example output, 16 drives can be observed as part of RADI50 device. Each drive has a capacity of 795 GB.
The RAID setup is organized by grouping eight (8) drives in a RAID5 device. Then all RAID5 devices form a RAID0 device.
NoteFor each RAID5 device there is a spare drive.
The total capacity of the RAID50 device is given by the following formula:
total capacity = (size of a single drive) X (number of drives in the RAID5 configuration — 2) X (number of RAID5 devices)
Replacing the terms in the formula with the values from our example, the total capacity of the RAID50 device is:
total capacity = 795 GB X (8 — 2) X 2 = 9540 GB
- Check the calculated size of the RAID50 device against the size shown by the following command:
mdadm --detail /dev/md/md50
Following is an example output:
/dev/md/md50:
Version : 1.2
Creation Time : Thu Aug 16 19:35:39 2018
Raid Level : raid0
Array Size : 9314494464 (8882.99 GiB 9538.04 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Fri Aug 17 04:23:27 2018
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Chunk Size : 512K
Consistency Policy : none
Name : any:md50
UUID : d35a4763:b4b9b490:b85614db:6aeb696a
Events : 2986
Number Major Minor RaidDevice State
0 9 125 0 active sync /dev/md/md5
2 9 123 1 active sync /dev/md/md5_2The calculated size is almost the size displayed in the example output: 9538.04 GB.
- Check the RAID level:
mdadm --detail /dev/md/md50
In the example output from the previous step, the RAID level is 0.
NoteIf the RAID level is RAID4, then change the RAID4 level to RAID0:
mdadm --grow --level 0 --raid-devices=2 /dev/md/md50
mdadm: level of /dev/md/md50 changed to raid0AttentionThe new RAID0 array needs to be reshaped a second time. This can take up to several hours to complete, depending on the size of the array. For example, expanding from 16 TB to 32 TB takes 11-12 hours.
Ensure the Array Size has increased to the correct amount and that all the RAID5 devices are included. If not, stop and do not continue! You may need to reshape to RAID4 and then back to RAID0.
Each set of eight (8) drives has one (1) parity drive and one (1) spare drive.
The total Array Size for eight (8) drives is:
total array size = 6 X (size of a single drive)
The total Array Size for 16 drives is:
total array size = (6+6) X (size of a single drive)
When the reshape process is completed it look similar to the following example:
mdadm --detail /dev/md/md50
/dev/md/md50:
Version : 1.2
Creation Time : Thu Aug 16 19:35:39 2018
Raid Level : raid0
Array Size : 9314494464 (8882.99 GiB 9538.04 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Fri Aug 17 04:23:27 2018
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Chunk Size : 512K
Consistency Policy : none
Name : any:md50
UUID : d35a4763:b4b9b490:b85614db:6aeb696a
Events : 2986
Number Major Minor RaidDevice State
0 9 125 0 active sync /dev/md/md5
2 9 123 1 active sync /dev/md/md5_2
- Check the size of the RAID50 device in 512–byte sectors:
blockdev --getsz /dev/md/md50
18,628,988,928
The first 2048 512– byte sectors are used to store the internal ThinkAgile CP VDO-specific metadata.
The RAID50 device now includes the new storage drives.
After including the new drives in the RAID array, increase the size of the VDO data. See Increasing the size of the VDO.