Downsize a RAID Partition
Here you will find out:
- why you may need to resize RAID
- how to downsize RAID array
- when DiskInternals can help you
Are you ready? Let's read!
So, when you need to resize RAID?
RAID is a pretty good option for storing and using data.
It increases productivity, storage capacity, reliability, and security for this data. For various reasons, you may need to resize (reduce or expand) a RAID partition. At first glance, this is not easy: what will happen to the information?
This article will help you learn all the pitfalls of the procedure of shrinking a RAID partition and provide incredibly useful tips!
Before you start downsizing a RAID partition
Note that before you start shrinking your RAID partition, it is best to have a backup of your data or create a disk image using DiskInternals RAID Recovery. Reducing the RAID partition is a safe procedure, but anything can happen, so you should take care of the safety of the files in advance.
DiskInternals RAID Recovery automatically restores files from RAID arrays connected to the controller, such as Adaptec, Dell, DDF-compatible devices, HP, MegaRaid, and Silicon RAID controllers. Different file systems like ZFS with RAIDZ and RAIDZ2 are also supported. In addition, data can be returned from Microsoft RAID software (dynamic disks), including JBOD and RAID 5, 0, 1 and others.
Your virtual disks can be mounted as local disks available through Windows Explorer, etc. The whole process will be supervised by the Recovery Wizard, so there’s nothing to worry about. After scanning, all found files will be available; select any of them and view them for free. After checking for their integrity, you will have no doubt about purchasing this product.
Here are instructions for recovering files using DiskInternals RAID Recovery:
Open RAID Recovery after downloading it to your computer. Then, in the new window, enable the Recovery Wizard and select the desired array to scan.
Then decide on the scanning mode:
- Fast recovery mode: takes less time, more superficial
- Full recovery mode: takes more time, but more thorough scanning
Now the program checks the status of the RAID array and controller and restores data where possible.
Preview your files for free.
The last step is to buy a license for RAID Recovery here and export the recovered files.
If you need help, the licensed version of the program gives you access to our support specialists for a year.
How to shrink a RAID array
So, how do you downsize a RAID partition?
First, boot into the system in safe mode. Then activate all the necessary modules.
After this, make active your RAID arrays:
e2fsck -f /dev/md2
After this, check the file system.
For example, let’s say /dev/md2 has a size of 30 GB, and you need a size of 20 GB. In this case, initially using resize2fs compresses the file system.
First, we need to compress the file system using resize2fs; in this case, it is better to reduce it to 15 GB, so that there is a small margin of security:
resize2fs /dev/md2 15G
Now let’s reduce /dev/md2 to 20 GB. The --size value should be in kilobytes (20 x 1024 x 1024 = 20971520):
mdadm --grow /dev/md2 --size=20971520
After that, the file system should be increased to the maximum possible value. (By default, resize2fs will use the maximum possible value.)
Run the file system check again, and after that, you can boot the system in normal mode.