RAID 4 Data Recovery
RAID 4 stripes data across several drives and stores all parity on one dedicated disk. It is less common than RAID 5, but it is still used by some NetApp systems (and as the basis for NetApp RAID-DP) and by certain NAS products.
Because every write updates the parity disk, that drive works harder than the others and can fail first. A second failure before the array is rebuilt leads to data loss.
Common RAID 4 Failures
- Failure of the dedicated parity drive followed by a data drive
- Two data drives failing at once
- Parity inconsistency after a power cut
- Controller or storage system failure
- Accidental volume deletion
How We Recover a RAID 4 Array
Because RAID 4 keeps all parity on one dedicated disk, any single missing data disk can be regenerated by XOR calculation from the others plus the parity disk. We establish the block size and disk order, rebuild the missing member virtually, and then read the file system – for NetApp systems this means interpreting WAFL aggregates, volumes and snapshots, which we can export as ordinary files.
Before You Do Anything
If your array has failed: do not force a rebuild, re-initialise the array, run CHKDSK/fsck, or swap drives between slots. Label every disk with its slot number, shut the system down cleanly if you can, and call us on 020 7064 4996. Most unrecoverable RAID cases we see were made worse by a rebuild attempted on the wrong disk.
See RAID & server data recovery for the servers, controllers and NAS systems we support.
Frequently asked questions
Do you recover NetApp systems?
Yes. We recover NetApp WAFL volumes built on RAID 4 and RAID-DP, working from images of the individual disks.
Free assessment, no obligation. Call 020 7064 4996 or use the form on this page – an engineer will tell you what can be recovered and what it will cost. Book online · Pricing · Locations