When setting up CentOS 7 on RAID6 storage for research purposes, the partitioning scheme becomes critical. While a single 1.3TB partition offers simplicity, it introduces several operational risks for multi-user scientific environments.

Scientific computing environments present unique storage challenges:

• Rapid growth in /usr/local from bioinformatics tools and custom software builds
• Unpredictable /home usage patterns from multiple researchers
• Critical system files competing with user data for space

A balanced approach using LVM (Logical Volume Manager) provides flexibility:

# Sample partitioning using LVM
pvcreate /dev/md0
vgcreate research_vg /dev/md0
lvcreate -L 50G -n root_lv research_vg
lvcreate -L 200G -n home_lv research_vg
lvcreate -L 500G -n usr_local_lv research_vg
lvcreate -l 100%FREE -n scratch_lv research_vg

Implement proactive monitoring with a simple bash script:

#!/bin/bash
THRESHOLD=85
PARTITIONS=("/" "/home" "/usr/local")

for part in ${PARTITIONS[@]}; do
  USAGE=$(df -h $part | awk 'NR==2 {print $5}' | cut -d'%' -f1)
  if [ $USAGE -ge $THRESHOLD ]; then
    echo "ALERT: Partition $part usage at ${USAGE}%" | mail -s "Storage Alert" admin@example.com
  fi
done

For research environments, consider these strategies:

• Implement disk quotas for /home directories
• Schedule monthly cleanup of /tmp and /var/tmp
• Use symbolic links for large datasets pointing to external storage

When /usr/local needs more space, dynamically expand it:

# Check free space in volume group
vgs research_vg

# Extend the logical volume
lvextend -L +100G /dev/research_vg/usr_local_lv

# Resize the filesystem
resize2fs /dev/research_vg/usr_local_lv

When setting up our new CentOS 7 server with 6x300GB drives in RAID6 (yielding ~1.3TB), we're facing a fundamental architectural decision: whether to implement a single large partition or follow traditional multi-partition schemes. As a computational biology lab, our usage patterns involve:

• Frequent software installations in /usr/local (mostly bioinformatics tools)
• User-generated data accumulating in /home directories
• Potential database growth in /var
• Regular system updates consuming / space

While the simplicity of a single partition is tempting, consider these technical impacts:

# Example of potential issues with full root partition
$ df -h /
Filesystem      Size  Used Avail Use% Mounted on
/dev/md0        1.3T  1.2T   50G  96% /

At 96% capacity, system performance degrades significantly. Critical operations like package updates may fail:

# Failed yum transaction due to lack of space
$ sudo yum update
Error: Transaction check error:
  installing package kernel-3.10.0-1160.92.1.el7.x86_64 needs 120MB on the /boot filesystem

A balanced approach might look like this:

# Suggested partition layout using LVM
$ sudo pvcreate /dev/md0
$ sudo vgcreate vg0 /dev/md0
$ sudo lvcreate -L 50G -n lv_root vg0
$ sudo lvcreate -L 100G -n lv_home vg0
$ sudo lvcreate -L 200G -n lv_usr_local vg0
$ sudo lvcreate -L 50G -n lv_var vg0
$ sudo lvcreate -L 50G -n lv_tmp vg0
$ sudo lvcreate -l 100%FREE -n lv_overflow vg0

This provides:

• Isolation of critical system directories
• Dedicated space for user software (/usr/local)
• Emergency expansion pool (lv_overflow)

Implement this bash script to monitor partition usage:

#!/bin/bash
THRESHOLD=80
PARTITIONS="/ /home /usr/local /var"

for part in $PARTITIONS; do
  USAGE=$(df -h $part | awk '{print $5}' | tail -1 | tr -d '%')
  if [ $USAGE -ge $THRESHOLD ]; then
    echo "WARNING: $part at ${USAGE}% capacity" | mail -s "Storage Alert" admin@lab.org
    # Auto-expand from overflow pool if needed
    if [ "$part" == "/usr/local" ]; then
      lvextend -r -L +20G /dev/vg0/lv_usr_local
    fi
  fi
done

For large partitions, XFS often outperforms ext4:

# Formatting commands for optimal performance
sudo mkfs.xfs -f -l size=64m -d agcount=32 /dev/vg0/lv_usr_local
sudo mkfs.xfs -f -i size=512 /dev/vg0/lv_home

# Add to /etc/fstab
/dev/vg0/lv_usr_local /usr/local xfs defaults,noatime,nodiratime 0 0
/dev/vg0/lv_home     /home      xfs defaults,noatime,nodiratime 0 0

Prevent home directory bloat with quotas:

# Enable quotas in /etc/fstab
/dev/vg0/lv_home /home xfs defaults,usrquota,grpquota 0 0

# Initialize and set quotas
sudo quotacheck -cug /home
sudo edquota -u username
# Set soft/hard limits in the editor