When you initially configured a single disk as RAID 0 (which technically isn't RAID at all), you now face a critical situation with a failing drive. The P410i controller presents unique challenges for this migration scenario.
HP Smart Array controllers typically require these conditions for RAID migration:
1. Sufficient physical disks available
2. Supported migration path (RAID 0→1 is valid)
3. Controller cache module (BBWC/FBWC) for safer operations
4. No pending drive failures during the process
Using hpacucli, here's the exact procedure:
# First check current array configuration:
hpacucli ctrl slot=0 ld all show
# Verify the new physical disk is detected:
hpacucli ctrl slot=0 pd all show
# Begin the migration (example for logical drive 1):
hpacucli ctrl slot=0 ld 1 modify raid=1 drives=1I:1:3,1I:1:4
# Monitor rebuild progress:
hpacucli ctrl slot=0 ld 1 show
- Always have verified backups before attempting migration
- The system will be I/O intensive during rebuild
- HP recommends BBWC/FBWC for migration operations
- Monitor SMART status on both disks post-migration
If controller limitations prevent migration, consider this software approach:
# Create a degraded RAID 1 array:
mdadm --create /dev/md0 --level=1 --raid-devices=2 missing /dev/sdb1
# Copy data from RAID 0:
dd if=/dev/sda1 of=/dev/md0 bs=1M status=progress
# After copy completes, add the original disk:
mdadm --manage /dev/md0 --add /dev/sda1
Common error messages and solutions:
Error: "The requested operation is not supported with the current configuration"
Solution: Ensure you have the latest firmware (P410i minimum 6.64)
Error: "Insufficient resources to complete request"
Solution: Clear controller cache or reboot into HP BIOS configuration
After migration to RAID 1, expect:
- ~20-30% write performance decrease
- Identical read performance to single disk
- Higher IOPS for read-intensive workloads
Many administrators (myself included) have made the mistake of configuring single disks as RAID 0 arrays, particularly on HP Smart Array controllers like the P410i. While this might have seemed like a good idea for consistency at the time, it creates serious redundancy issues when drives fail.
The fundamental issue is that RAID 0 provides no redundancy, while RAID 1 requires at least two disks. When your single-disk "RAID 0" starts failing, you're in a race against time to establish redundancy.
Here's how to convert your failing single-disk RAID 0 to a proper RAID 1 array using the P410i controller:
# First, identify your current array configuration hpacucli ctrl all show config detail # Example output: # logicaldrive 1 (136.7 GB, RAID 0, OK) # physicaldrive 1I:1:1 (port 1I:box 1:bay 1, SAS, 146 GB, Failed) # Prepare your new drive (assuming bay 2 is empty) hpacucli ctrl slot=0 physicaldrive 1I:1:2 insert drives=1I:1:2 # Convert the array (this is the critical step) hpacucli ctrl slot=0 logicaldrive 1 modify raid=1 drives=1I:1:1,1I:1:2 forced
Note that the forced flag is required because we're modifying a degraded array. The controller will:
- Preserve all existing data on the original drive
- Initialize the new drive
- Begin mirroring the data
You can monitor the progress with:
hpacucli ctrl slot=0 show status # Look for "Rebuilding (x%)" status # Typical rebuild time for a 146GB drive: 2-4 hours
After completion, verify the new configuration:
hpacucli ctrl slot=0 show config detail # Should show: # logicaldrive 1 (136.7 GB, RAID 1, OK) # physicaldrive 1I:1:1 (port 1I:box 1:bay 1, SAS, 146 GB, OK) # physicaldrive 1I:1:2 (port 1I:box 1:bay 2, SAS, 146 GB, OK)
If your original drive fails during this process, you'll need to:
- Replace the failed drive
- Create a new RAID 1 array using your backup
- Restore from backup
If the HP utility fails, you can try Linux software RAID (mdadm):
# Install mdadm if not present sudo apt-get install mdadm # Create a new RAID 1 array sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda /dev/sdb # Copy data from the original single-disk RAID 0 sudo dd if=/dev/sda of=/dev/md0 bs=4M status=progress