Exadata Storage Server (Cell Node)
Exadata Storage Servers, also called Cell Servers, are specialized storage nodes in Oracle Exadata.
Unlike traditional storage, Exadata storage performs database-aware processing such as Smart Scan, Storage Index filtering, and Flash Cache acceleration.
1. What is an Exadata Storage Server?
| Component | Description |
|---|
| Storage Server (Cell) | Physical server storing database data |
| Cell Server Software | Software running on storage nodes to manage I/O operations |
| Smart Scan | Offloads SQL processing to storage layer |
| Flash Cache | High-speed flash storage used for caching data |
2. Exadata Rack Storage Components
| Component | Typical Full Rack Count |
|---|
| Database Servers | 8 |
| Storage Servers | 14 |
| Network Switches | 2 |
3. Storage Server Processes
| Process | Purpose |
|---|
| CELLSRV | Main process handling I/O operations |
| MS (Management Server) | Monitors storage server health |
| RS (Restart Server) | Restarts failed services automatically |
4. Smart Scan Feature
Smart Scan allows Exadata to filter rows and columns directly on the storage servers.
Instead of sending full data blocks to the database server, only required rows are returned.
Traditional Storage:
Database Server → Reads full blocks → Filters rows
Exadata Smart Scan:
Database Server → Storage Server filters rows → Sends only required data
5. Storage Index
Storage Index is an in-memory structure maintained by storage servers.
It helps avoid unnecessary disk reads by tracking minimum and maximum column values in storage regions.
6. Flash Cache
| Flash Usage | Description |
|---|
| Read Cache | Caches frequently accessed data blocks |
| Write Back Cache | Improves write performance |
| Smart Flash Cache | Automatically manages hot data |
7. Exadata Disk Architecture
Physical Disk
↓
LUN
↓
Cell Disk
↓
Grid Disk
↓
ASM Disk
↓
Database Files
8. Useful Storage Server Commands
cellcli -e list cell detail
cellcli -e list celldisk
cellcli -e list griddisk
cellcli -e list flashcache
9. Advantages of Exadata Storage Servers
| Feature | Benefit |
|---|
| Smart Scan | Reduces data transfer and improves query performance |
| Storage Index | Avoids unnecessary disk reads |
| Flash Cache | High-speed data access |
| RDMA Network | Ultra-low latency communication |
Caution: Your use of any information or materials on this website is entirely at your own risk. It is provided for educational purposes only. It has been tested internally, however, we do not guarantee that it will work for you. Ensure that you run it in your test environment before using.
Thank you,
Rajasekhar Amudala
Email: br8dba@gmail.com
Linkedin: https://www.linkedin.com/in/rajasekhar-amudala/
Oracle Exadata Rack Size
| Rack Size | DB Servers | Storage Servers | Typical Use |
|---|
| Eighth Rack | 2 | 3 | Dev / Test / DR |
| Quarter Rack | 2 | 5 | Small–Medium Production |
| Half Rack | 4 | 7 | Medium–Large Production |
| Full Rack | 8 | 14 | Large / Mission Critical |
Exadata Interconnect Network / Bond Speed (X5 – X11M)
| Exadata Model | Network Type | Speed Per Port | Bonded Speed |
| X5 | InfiniBand (FDR) | 56 Gbps | 56 Gbps × 2 = 112 Gbps |
| X6 | InfiniBand (FDR) | 56 Gbps | 56 Gbps × 2 = 112 Gbps |
| X7 | InfiniBand (EDR) | 100 Gbps | 100 Gbps × 2 = 200 Gbps |
| X8 | InfiniBand (EDR) | 100 Gbps | 100 Gbps × 2 = 200 Gbps |
| X8M | RoCE (RDMA over Converged Ethernet) | 100 Gbps | 100 Gbps × 2 = 200 Gbps |
| X9M | RoCE | 100 Gbps | 100 Gbps × 2 = 200 Gbps |
| X10M | RoCE | 100 Gbps | 100 Gbps × 2 = 200 Gbps |
| X11M | RoCE | 100 Gbps | 100 Gbps × 2 = 200 Gbps |
Exadata Networking Overview
Oracle Exadata uses a high-speed low-latency internal network connecting
Database Servers, Storage Servers (Cells), and Switches.
This network enables features like Smart Scan, ASM rebalance, RAC cache fusion, and high-speed data transfer.
1. Client Network
| Feature | Description |
|---|
| Purpose | Application connections to the database |
| Traffic | SQL queries, application requests |
| Network Type | Standard Ethernet (10Gb / 25Gb / 40Gb / 100Gb) |
| Example Flow | Application → Client Network → SCAN Listener → RAC Node |
2. RAC Private Interconnect
The private interconnect network is used for communication between RAC database nodes.
| Usage | Description |
|---|
| Cache Fusion | Transfer blocks between RAC nodes |
| Cluster Heartbeat | Maintains RAC node communication |
| Parallel Query | Data exchange between nodes |
| Exadata Model | Networking Technology |
|---|
| X2 – X6 | InfiniBand (40–56 Gb) |
| X7 – X8 | InfiniBand (100 Gb) |
| X8M and Later | RoCE (RDMA over Converged Ethernet) |
3. Storage Network (Database → Storage Cells)
Database nodes communicate with Exadata storage servers using a high-speed RDMA network.
| Feature | Description |
|---|
| Smart Scan | Query processing pushed to storage servers |
| Block Reads | Fast data retrieval from storage cells |
| ASM Rebalance | High-speed disk rebalance operations |
| Flash Cache Reads | Access flash storage with very low latency |
Exadata Network Architecture
| Component | Typical Full Rack Count |
|---|
| Database Servers | 8 |
| Storage Servers | 12 |
| Network Switches | 2 (Redundant) |
Important Exadata Networking Commands
cat /proc/net/bonding/bondib0
ip addr
rdma link
ibstat
Key Advantages of Exadata Networking
| Feature | Benefit |
|---|
| RDMA | Ultra low latency communication |
| High Bandwidth | Faster query processing |
| Redundant Switches | High availability |
| Bonded Interfaces | Network failover and load balancing |
Caution: Your use of any information or materials on this website is entirely at your own risk. It is provided for educational purposes only. It has been tested internally, however, we do not guarantee that it will work for you. Ensure that you run it in your test environment before using.
Thank you,
Rajasekhar Amudala
Email: br8dba@gmail.com
Linkedin: https://www.linkedin.com/in/rajasekhar-amudala/
Oracle Exadata Rack Size
| Rack Size | DB Servers | Storage Servers | Typical Use |
|---|
| Eighth Rack | 2 | 3 | Dev / Test / DR |
| Quarter Rack | 2 | 5 | Small–Medium Production |
| Half Rack | 4 | 7 | Medium–Large Production |
| Full Rack | 8 | 14 | Large / Mission Critical |
Oracle Exadata DB Server (Compute Node) – Memory (X5 to X11M)
| Exadata Model | Memory / DB Server | Quarter Rack (2 DB) | Half Rack (4 DB) | Full Rack (8 DB) |
|---|
| X5 | 256 GB | 256 GB × 2 = 512 GB | 256 GB × 4 = 1 TB | 256 GB × 8 = 2 TB |
| X6 | 1.5 TB | 1.5 TB × 2 = 3 TB | 1.5 TB × 4 = 6 TB | 1.5 TB × 8 = 12 TB |
| X7 | 1.5 TB | 1.5 TB × 2 = 3 TB | 1.5 TB × 4 = 6 TB | 1.5 TB × 8 = 12 TB |
| X8 | 1.5 TB | 1.5 TB × 2 = 3 TB | 1.5 TB × 4 = 6 TB | 1.5 TB × 8 = 12 TB |
| X8M | 1.5 TB | 1.5 TB × 2 = 3 TB | 1.5 TB × 4 = 6 TB | 1.5 TB × 8 = 12 TB |
| X9M | 2 TB | 2 TB × 2 = 4 TB | 2 TB × 4 = 8 TB | 2 TB × 8 = 16 TB |
| X10M | 3 TB | 3 TB × 2 = 6 TB | 3 TB × 4 = 12 TB | 3 TB × 8 = 24 TB |
| X11M | 3 TB | 3 TB × 2 = 6 TB | 3 TB × 4 = 12 TB | 3 TB × 8 = 24 TB |
Caution: Your use of any information or materials on this website is entirely at your own risk. It is provided for educational purposes only. It has been tested internally, however, we do not guarantee that it will work for you. Ensure that you run it in your test environment before using.
Thank you,
Rajasekhar Amudala
Email: br8dba@gmail.com
Linkedin: https://www.linkedin.com/in/rajasekhar-amudala/
Oracle Exadata Rack Size
| Rack Size | DB Servers | Storage Servers | Typical Use |
|---|
| Eighth Rack | 2 | 3 | Dev / Test / DR |
| Quarter Rack | 2 | 5 | Small–Medium Production |
| Half Rack | 4 | 7 | Medium–Large Production |
| Full Rack | 8 | 14 | Large / Mission Critical |
Oracle Exadata DB Server (Compute Node) – CPU (X5 to X11M)
| Exadata Model | CPU (Per DB Server) | Total (Per DB Server) | Total CPU (Quarter Rack – 2 DB Servers) | Total CPU (Half Rack – 4 DB Servers) | Total CPU (Full Rack – 8 DB Servers) |
|---|
| X5 | 2 × 18-core Intel | 36 cores | 36 × 2 = 72 cores | 36 × 4 = 144 cores | 36 × 8 = 288 cores |
| X6 | 2 × 22-core Intel | 44 cores | 44 × 2 = 88 cores | 44 × 4 = 176 cores | 44 × 8 = 352 cores |
| X7 | 2 × 24-core Intel | 48 cores | 48 × 2 = 96 cores | 48 × 4 = 192 cores | 48 × 8 = 384 cores |
| X8 | 2 × 24-core Intel | 48 cores | 48 × 2 = 96 cores | 48 × 4 = 192 cores | 48 × 8 = 384 cores |
| X8M | 2 × 24-core Intel | 48 cores | 48 × 2 = 96 cores | 48 × 4 = 192 cores | 48 × 8 = 384 cores |
| X9M | 2 × 32-core Intel | 64 cores | 64 × 2 = 128 cores | 64 × 4 = 256 cores | 64 × 8 = 512 cores |
| X10M | 2 × 96-core AMD | 192 cores | 192 × 2 = 384 cores | 192 × 4 = 768 cores | 192 × 8 = 1536 cores |
| X11M | 2 × 96-core AMD | 192 cores | 192 × 2 = 384 cores | 192 × 4 = 768 cores | 192 × 8 = 1536 cores |
Caution: Your use of any information or materials on this website is entirely at your own risk. It is provided for educational purposes only. It has been tested internally, however, we do not guarantee that it will work for you. Ensure that you run it in your test environment before using.
Thank you,
Rajasekhar Amudala
Email: br8dba@gmail.com
Linkedin: https://www.linkedin.com/in/rajasekhar-amudala/
Exadata Part Replacement – Quick Notes
Hot Swappable Components
| Component | Replacement Type |
|---|
| LUN / Disk | Hot Swappable |
| Fan | Hot Swappable |
| Single Power Supply | Hot Swappable |
| Flash Disk (From X7) | Hot Swappable |
| DIMM | Shutdown Required |
| Motherboard | Shutdown Required |
Before Replacement (If Shutdown Required)
**** Always verify ASM rebalance activity before making grid disks inactive.
select * from gv$asm_operation;
cellcli -e list griddisk attributes name, asmmodestatus, asmdeactivationoutcome, status
cellcli -e alter griddisk all inactive
cellcli -e list griddisk attributes name, asmmodestatus, asmdeactivationoutcome, status
service celld status
service celld stop
shutdown -h now
After Replacement
service celld status
cellcli -e list griddisk attributes name, asmmodestatus, asmdeactivationoutcome
cellcli -e alter griddisk all active
cellcli -e list griddisk attributes name, asmmodestatus, asmdeactivationoutcome
select * from gv$asm_operation;
Caution: Your use of any information or materials on this website is entirely at your own risk. It is provided for educational purposes only. It has been tested internally, however, we do not guarantee that it will work for you. Ensure that you run it in your test environment before using.
Thank you,
Rajasekhar Amudala
Email: br8dba@gmail.com
Linkedin: https://www.linkedin.com/in/rajasekhar-amudala/