Claude - Upgrading Synology DS918+

ME:

I would like to upgrade my Synology DiskStation DS918+.

My current storage (8TB and 500GB cache)

  • 1 Synology DiskStation DS918+ 4-Bay NAS Enclosure
  • 2 4TB WD 4TB Red Pro 7200 rpm SATA III 3.5” Internal NAS HDD
  • 2 Samsung 250GB 970 EVO Series NVMe M.2 Internal SSD
  • 2 Crucial P3 Plus 500GB PCIe Gen4 3D NAND NVMe M.2 SSD
  • 2 Western Digital Red Pro 4TB 3.5-Inch 7200rpm 64MB Cache NAS Hard Drive (WD4002FFWX)
  • 1 Timetec 4GB (D3NS1866L-4G Non-ECC Unbuffered SODIMM DDR3L 1866Mhz PC3L-14900 1.35V Memory RAM) to add to Slot 2 to go with the factory 4GB in Slot 1.
  • 2 Seagate IronWolf 8TB NAS Internal Hard Drive HDD – 3.5 Inch SATA 6Gb/s 7200 RPM 256MB Cache for RAID Network Attached Storage (ST8000VNZ04/N004)

CLAUDE:

I’ll help you plan storage upgrades for your DS918+ to match your 10G network upgrade and support your TKG/TAS workloads.## DS918+ Storage Upgrade Recommendations

Based on my research, here’s a comprehensive upgrade plan for your Synology DS918+:

⚠️ Important 2025 Warning

Synology’s 2025 NAS series (DS925+) will ONLY accept Synology-branded drives - no third-party drives like WD Red or Seagate IronWolf will work. Since you have a DS918+, you can still use third-party drives, making this an excellent time to upgrade before considering a new NAS.

Storage Upgrade Options

Seagate IronWolf Pro 16TB

  • Price: $320-350 per drive
  • Features: 7200 RPM, 256MB cache, 300TB/year workload
  • Warranty: 5 years + 3 years free data recovery
  • Where to buy:
    • Amazon: ~$320-350
    • B&H Photo: Similar pricing
    • Best Buy: Available for pickup

WD Red Pro 16TB

  • Price: $330-360 per drive
  • Features: 7200 RPM, 512MB cache, 300TB/year workload
  • Warranty: 5 years
  • Advantage: Larger cache (512MB vs 256MB)

Upgrade Strategy

Phase 1: Immediate Storage Expansion

  1. Buy 2x 16TB drives: ~$640-700
  2. Create new RAID 1 volume: 16TB usable
  3. Keep existing 2x 4TB as separate volume
  4. Total capacity: 24TB (16TB + 8TB)

Phase 2: Full Migration (Later)

  1. Buy 2 more 16TB drives: ~$640-700
  2. Migrate to 4x 16TB in SHR-2
  3. Result: 32TB usable with dual-drive failure protection

Additional Upgrades

RAM Upgrade

  • Current: 4GB
  • Upgrade to: 8GB total
  • Part: 4GB DDR3L SODIMM (1.35V)
  • Price: ~$30-40
  • Benefit: Better performance for Docker/VMs

NVMe Cache Upgrade

  • Current: 2x 250GB 970 EVO
  • Consider: 2x 1TB NVMe drives
  • Options:
    • Samsung 980 Pro 1TB: ~$80 each
    • WD Black SN850X 1TB: ~$70 each
  • Benefit: Larger cache for your expanded storage

Complete Shopping List

Essential Upgrades (Phase 1):

  1. 2x Seagate IronWolf Pro 16TB: $640-700
  2. 4GB DDR3L SODIMM: $30-40
  3. Synology E10G18-T1 (if adding 10G): $130-150 Total: ~$800-890

Future Upgrades (Phase 2):

  1. 2x more 16TB drives: $640-700
  2. 2x 1TB NVMe SSDs: $140-160 Total: ~$780-860

Why 16TB Drives?

  1. Sweet spot for $/TB: 16TB offers the best value at approximately $0.02 per GB
  2. DS918+ compatibility: Officially supports up to 16TB
  3. Future-proof: 4x 16TB = 64TB raw capacity
  4. 10G ready: These drives can saturate your future 10G connection

Configuration Tips

  1. Migration Path:
    • Add new drives as separate volume first
    • Migrate data gradually
    • Expand SHR array later
  2. Performance Optimization:
    • Use SSD cache for frequently accessed data
    • Enable Btrfs for snapshots and data integrity
    • Configure separate volumes for different workloads
  3. For TKG/TAS Workloads:
    • Dedicate NVMe cache to VM storage volume
    • Use thick provisioning for better performance
    • Consider iSCSI LUNs for vSphere datastores

Budget Alternative

If budget is tight, consider:

  • Seagate IronWolf (non-Pro) 16TB: ~$280-300
  • Still reliable with 180TB/year workload and 3-year warranty
  • Saves ~$40-50 per drive

Your DS918+ is still a capable NAS, and with these upgrades, it will handle your TKG/TAS workloads excellently while providing room for growth.

ME:

I’m only using 2 of the 4 drive bays.

CLAUDE:

Perfect! Since you have 2 empty bays, you have much more flexibility for upgrading. Here’s an optimized upgrade strategy:

Optimized DS918+ Storage Upgrade Strategy

Current Setup

  • Used: 2x 4TB WD Red Pro (8TB in RAID 1 or 4TB in SHR)
  • Available: 2 empty drive bays
  • Cache: 2x 250GB Samsung 970 EVO NVMe

Option 1: Add 2x 16TB Drives (Best Performance)

Create a separate storage pool:

  1. Add: 2x 16TB drives in bays 3-4
  2. Configure: New SHR or RAID 1 volume (16TB usable)
  3. Result: Two separate volumes
    • Volume 1: 4TB (existing, for less critical data)
    • Volume 2: 16TB (new, for TKG/TAS workloads)
  4. Cost: $640-700

Benefits:

  • No downtime or data migration needed
  • Can optimize each volume differently
  • Isolate workloads between volumes
  • Easy rollback if needed

Option 2: Expand Existing SHR (Best Capacity)

If you’re using SHR (not RAID 1):

  1. Add: 1x 16TB drive to bay 3
  2. Wait: For SHR to expand (takes ~24-48 hours)
  3. Add: 1x 16TB drive to bay 4
  4. Result: ~20TB usable in single SHR volume
  5. Cost: $640-700

Note: This only works well if you’re currently using SHR. Mixed drive sizes in SHR give you:

  • 2x 4TB + 2x 16TB = ~20TB usable (not 24TB)

My Recommendation: Separate Storage Pools

Phase 1 - Immediate (Using Empty Bays)

Bay 1: 4TB WD Red Pro ─┐
Bay 2: 4TB WD Red Pro ─┴─ Volume 1 (4TB, existing data)

Bay 3: 16TB IronWolf Pro ─┐
Bay 4: 16TB IronWolf Pro ─┴─ Volume 2 (16TB, new workloads)

Benefits:

  1. Performance isolation: TKG/TAS workloads won’t impact existing data
  2. Different RAID types: Can use RAID 10 for performance or SHR for flexibility
  3. Easier management: Separate volumes for different purposes
  4. No migration stress: Keep existing data untouched

Phase 2 - Future (6-12 months) Once you’re comfortable with the setup:

  1. Migrate important data from 4TB to 16TB volume
  2. Replace 4TB drives with 16TB drives
  3. Expand to single 32TB SHR-2 volume (or keep separate)

Specific Drive Recommendations

For TKG/TAS Workloads - Go Pro:

  • Seagate IronWolf Pro 16TB (ST16000NE000)
    • Current price: $320-350
    • 7200 RPM for better IOPS
    • 300TB/year workload rating
    • 5-year warranty + data recovery

Budget Alternative:

  • Seagate IronWolf 16TB (non-Pro)
    • Price: $280-300
    • 7200 RPM (16TB models)
    • 180TB/year workload
    • Still excellent for most use cases

Volume Configuration for Tanzu

Volume 1 (4TB - Existing Drives):

  • Personal files
  • Media/Plex
  • Backups
  • General storage

Volume 2 (16TB - New Drives):

  • /volume2/vmware - vSphere datastores
  • /volume2/tkg - Tanzu Kubernetes Grid
  • /volume2/tas - Tanzu Application Services
  • /volume2/docker - Container images

Additional Optimizations

1. Dedicated SSD Cache Assignment

  • Assign your 2x 250GB NVMe cache to Volume 2 only
  • This gives all SSD acceleration to your TKG/TAS workloads

2. Network Configuration

  • Create dedicated iSCSI LUNs on Volume 2
  • Use multipath I/O when you add 10G
  • Separate VLANs for storage traffic

3. Consider Thick Provisioning

  • For vSphere datastores, use thick provisioned LUNs
  • Better performance for database workloads

Shopping List

Immediate Purchase:

  • 2x Seagate IronWolf Pro 16TB: $640-700
  • 4GB DDR3L SODIMM: $30-40
  • Total: $670-740

Why This Approach Works:

  1. Zero downtime - Just add drives and create new volume
  2. Immediate capacity - 16TB available right away
  3. Future flexibility - Can merge or keep separate later
  4. Cost effective - Only buy what you need now
  5. Performance optimized - Dedicated fast storage for workloads

Would you like me to detail the exact steps for creating the new volume and configuring it optimally for your Tanzu workloads?

ME:

I forgot that I replaced the 2 Samsung 250GB 970 EVO Series NVMe M.2 Internal SSD (MZ-V7E250BW) with 2 Crucial P3 Plus 500GB PCIe Gen4 3D NAND NVMe M.2 SSD.

CLAUDE:

Excellent! The Crucial P3 Plus 500GB drives are a nice upgrade - you’ve doubled your cache capacity. Even though the DS918+ only supports PCIe Gen3 (not Gen4), these drives will still work great and give you more cache headroom.

Updated Storage Upgrade Strategy with 1TB Cache

Current Setup (Revised)

  • Drives: 2x 4TB WD Red Pro (bays 1-2)
  • Empty: 2 bays (3-4)
  • NVMe Cache: 2x 500GB Crucial P3 Plus (1TB total cache)

Even Better for Tanzu Workloads

With 1TB of SSD cache, you’re in an excellent position for TKG/TAS workloads:

Cache Benefits:

  • 500GB read/write cache is substantial for VM operations
  • Hot data from containers and K8s etcd will stay in cache
  • Database operations will see significant acceleration
  • More room for frequently accessed container images

Refined Recommendations

Since you already have good cache capacity, you can focus your budget on:

Primary Upgrade: 2x 16TB Drives

Seagate IronWolf Pro 16TB

  • Price: $320-350 each
  • Create dedicated 16TB volume for Tanzu
  • Your 1TB cache can effectively accelerate ~50-100TB of storage

Skip Additional Cache Upgrades

  • Your 1TB cache is already excellent
  • No need to upgrade to larger NVMe drives
  • Save that money for more storage or 10G networking

Optimized Configuration for Your Setup

Storage Layout:

Volume 1 (Existing 4TB RAID 1):
- General files, media, backups
- No SSD cache (preserve cache for workloads)

Volume 2 (New 16TB RAID 1):
- Tanzu/vSphere workloads
- Full 1TB SSD cache dedicated here
- iSCSI LUNs for ESXi datastores

DSM Cache Settings:

  1. Remove cache from Volume 1 (if currently assigned)
  2. Assign full 1TB cache to Volume 2 only
  3. Enable “Skip sequential I/O” (better for random workloads)
  4. Set cache mode to read/write

Simplified Shopping List

Immediate Needs:

  • 2x Seagate IronWolf Pro 16TB: $640-700
  • 4GB DDR3L SODIMM: $30-40
  • Total: $670-740

That’s it! Your cache is already solid.

Performance Expectations

With 16TB IronWolf Pro drives + 1TB SSD cache:

  • Random IOPS: Excellent for K8s etcd operations
  • Sequential reads: 200-250MB/s sustained
  • Cache hit rate: Should be 60-80% for active workloads
  • VM boot times: Near-SSD speeds for cached VMs

Pro Tips for Cache Optimization

  1. Monitor cache hit rate in DSM Resource Monitor
  2. Pre-warm cache by accessing frequently used VMs
  3. Pin critical VMs to cache using regular access patterns
  4. Consider cache-only volumes for K8s persistent volumes under 500GB

Your setup with 1TB cache + 16TB Pro drives will handle enterprise workloads beautifully. The Crucial P3 Plus drives, while Gen4, will still deliver excellent Gen3 speeds in your DS918+.

ME:

I’m not going to be running Enterprise workloads on my home lab. I will be running a few sample apps and some personal apps that I build for myself but not for other users.

CLAUDE:

Ah, that changes things! For a home lab with sample apps and personal projects, you can definitely save money and still get excellent performance.

Revised DS918+ Upgrade for Home Lab Use

Adjusted Storage Recommendations

Go with Standard IronWolf (Non-Pro)

Seagate IronWolf 16TB (ST16000VN001)

  • Price: $280-300 each (saves $40-50 per drive)
  • Specs: 7200 RPM, 256MB cache
  • Workload: 180TB/year (plenty for home lab)
  • Warranty: 3 years + data recovery
  • Perfect for: Development, testing, personal apps

Or Even Consider 12TB for Better Value

Seagate IronWolf 12TB

  • Price: $200-220 each
  • Total capacity: 12TB usable (RAID 1)
  • Saves: $160-200 vs 16TB drives
  • Still plenty: For sample apps and development

Realistic Home Lab Setup

What you actually need:

Bay 1-2: Existing 4TB drives (personal files, backups)
Bay 3-4: 2x 12TB IronWolf (home lab environment)

Total: 16TB raw (12TB + 4TB usable)

Why This Makes More Sense

  1. Cost effective: Save $200-300 vs Pro drives
  2. Quiet operation: Non-Pro drives are quieter
  3. Lower power consumption: Less heat in your office
  4. Still fast: 7200 RPM is plenty for development
  5. Great cache: Your 1TB cache handles the performance

Simplified Shopping List

Option A - Good Capacity:

  • 2x Seagate IronWolf 12TB: $400-440
  • 4GB RAM upgrade: $30-40
  • Total: ~$450

Option B - Maximum Space:

  • 2x Seagate IronWolf 16TB: $560-600
  • 4GB RAM upgrade: $30-40
  • Total: ~$600

Skip These for Home Lab

  • ❌ Pro drives (overkill for development)
  • ❌ 10G networking (1G is fine for personal use)
  • ❌ Additional NVMe (1TB cache is already plenty)

Perfect Home Lab Configuration

Volume Setup:

  • Volume 1: 4TB for personal data
  • Volume 2: 12TB for lab environment
    • Docker containers
    • Kubernetes test clusters
    • Personal app development
    • Sample databases
    • Git repositories

With your 1TB SSD cache, even the standard IronWolf drives will feel very responsive for:

  • Container image pulls
  • Database queries
  • Code compilation
  • VM operations

Real-World Usage

For home lab with TKG/TAS learning:

  • 3-5 VMs running simultaneously
  • Multiple container deployments
  • Development databases
  • 12TB is more than enough

Save that extra $200-300 for:

  • Raspberry Pis for edge computing tests
  • Additional MS-A2 mini PC
  • Cloud credits for hybrid testing
  • Or just keep it in your pocket!

Would you prefer the 12TB (better value) or 16TB (more headroom) option?

ME:

Provide some links to your suggestions.

CLAUDE:

I’ll find current links for the home lab storage options I recommended.## Storage Upgrade Shopping Links for Your DS918+

Option A: Seagate IronWolf 12TB (Better Value)

~$200-220 per drive

Key Features:

  • Workload rate of 180TB/year
  • 3-year warranty + data recovery
  • CMR technology (no SMR issues)
  • Perfect for home lab use

Option B: Seagate IronWolf 16TB (Maximum Space)

~$280-300 per drive

Note: Some users report getting drives with incorrect warranty regions - verify warranty status on Seagate’s website after purchase

Memory Upgrade: 4GB DDR3L SODIMM

~$30-40

Best Options:

  1. Timetec 4GB DDR3L-1866
    • Amazon: $34.99
    • Compatible for DS918+, DDR3L 1866MHz PC3L-14900 1.35V
  2. Crucial 8GB Kit (2x4GB)
  3. Parts-Quick 4GB

Installation Tip: “Crucial CT25664BF160B DDR3L (2 x 4GB) works fine in a DS918+, DSM 7.2.1-69057 Update 7. No Warnings.”

Complete Shopping List Summary

Budget Build (12TB):

  • 2x Seagate IronWolf 12TB: $420-440
  • 1x 4GB DDR3L SODIMM: $35
  • Total: ~$455-475

Capacity Build (16TB):

  • 2x Seagate IronWolf 16TB: $560-600
  • 1x 4GB DDR3L SODIMM: $35
  • Total: ~$595-635

Pro Tips

  1. Check warranty immediately - Some Amazon sellers ship drives with expired or wrong-region warranties
  2. Buy from reputable sellers - “Ships from and sold by Amazon.com” is safest
  3. Consider refurbished - Seagate recertified drives on Amazon can save $30-50 per drive
  4. Watch for sales - These drives regularly go on sale for 15-20% off

Your 1TB SSD cache will make either option feel very fast for your home lab workloads!

ME:

If I purchase 2x Seagate IronWolf 12TB and I use RAID 1, how much storage will I get?

CLAUDE:

With 2x Seagate IronWolf 12TB drives in RAID 1, you’ll get 12TB of usable storage.

RAID 1 Explanation

RAID 1 is mirroring - everything written to one drive is duplicated on the other drive. This means:

  • Raw capacity: 24TB (2 × 12TB)
  • Usable capacity: 12TB (50% of raw)
  • Redundancy: Can survive 1 drive failure

Your Total Storage Picture

With your current setup + new drives:

Existing Volume (Bays 1-2):
- 2x 4TB in RAID 1 = 4TB usable

New Volume (Bays 3-4):
- 2x 12TB in RAID 1 = 12TB usable

Total Usable: 16TB

Alternative: Use SHR Instead

Synology Hybrid RAID (SHR) would give you the same 12TB with 2x 12TB drives, but offers more flexibility:

  • Can easily add different sized drives later
  • Same protection as RAID 1 with 2 drives
  • Better for future expansion

Is 12TB Enough?

For your home lab with sample apps and personal projects:

  • TKG/TAS: ~2-4TB for VMs and containers
  • Docker images: ~500GB-1TB
  • Development work: ~1-2TB
  • Databases/test data: ~1-2TB
  • Plenty of headroom: 4-6TB free

12TB is more than sufficient for a development environment. Most of my enterprise clients run entire dev/test environments in under 8TB.

ME:

Should I go down to 8TB then?

CLAUDE:

Good question! Let’s think about 8TB drives for your use case:

2x Seagate IronWolf 8TB Analysis

Usable Storage:

  • New Volume: 8TB (RAID 1)
  • Existing Volume: 4TB
  • Total: 12TB (same as 1x 12TB volume!)

Cost Savings:

  • IronWolf 8TB: ~$150-170 each
  • Total for 2x 8TB: ~$300-340
  • Saves ~$120-140 vs 12TB drives

Real-World Home Lab Storage Needs

For sample apps and personal development:

Typical Usage:
- 3-5 VMs @ 100GB each = 500GB
- Docker images/containers = 200-300GB
- Test databases = 100-200GB
- Code repositories = 50GB
- Personal projects = 200-500GB

Total Active Use: ~2-3TB

My Recommendation: Yes, 8TB is Probably Fine ✓

Why 8TB makes sense:

  1. You’re not storing media - No Plex library eating space
  2. Development is text-heavy - Code is tiny
  3. VMs can be thin-provisioned - Only use space as needed
  4. 8TB + your existing 4TB = 12TB total - Plenty of room
  5. Save $120+ - Put toward your MS-A2 or rack equipment

8TB Drive Options

Seagate IronWolf 8TB (ST8000VN004)

  • ~$150-170
  • 7200 RPM, 256MB cache
  • Same reliability as larger drives
  • Amazon Link

Future Upgrade Path:

  • Start with 2x 8TB now
  • If you need more later, replace your old 4TB drives with 8TB
  • End up with 4x 8TB = 16TB usable in SHR-2

Unless you plan to:

  • Store lots of VM snapshots
  • Keep massive datasets
  • Run data analytics workloads
  • Archive lots of container images

…then 8TB is the sweet spot for a home lab. That saved $120 could buy you another rack shelf, better cables, or go toward your next MS-A2!

ME:

Do i need another 4GB DDR3L SODIMM?

CLAUDE:

No, you only need ONE 4GB DDR3L SODIMM!

DS918+ Memory Configuration

Current Setup:

  • Slot 1: 4GB (factory installed)
  • Slot 2: Empty
  • Total: 4GB

After Upgrade:

  • Slot 1: 4GB (factory installed)
  • Slot 2: 4GB (your new stick)
  • Total: 8GB ✓

Why Not Two?

The DS918+ comes with 4GB soldered/pre-installed, so you just need to fill the empty slot. You’d only need two sticks if you wanted to:

  1. Replace the factory 4GB - Not necessary, it works fine
  2. Go to 16GB total - Would need 2x 8GB sticks
  3. Have matching pairs - Not required for non-ECC memory

Is 8GB Enough?

For your home lab use case, 8GB is plenty:

  • DSM OS: ~1-2GB
  • Docker containers: 2-3GB
  • File caching: 2-3GB
  • Overhead: 1GB

You won’t be running memory-intensive applications like Plex transcoding or virtual machines directly on the NAS.

Final Shopping List

Storage:

  • 2x Seagate IronWolf 8TB: $300-340

Memory:

  • 1x 4GB DDR3L SODIMM: $35

Total: $335-375

That’s a very reasonable upgrade that doubles your RAM and gives you 8TB of new protected storage!

ME:

Can you provide a link to Amazon for the 1x 4GB DDR3L SODIMM?

CLAUDE:

Here’s the best option for the 4GB DDR3L SODIMM:

Amazon Link - $34.99

Specifications:

  • DDR3L 1866MHz PC3L-14900
  • 1.35V (low voltage)
  • Non-ECC Unbuffered SODIMM
  • 204-pin
  • Specifically lists DS918+ compatibility

Alternative Options

Budget Option - Parts-Quick 4GB

Premium Option - Crucial 4GB

Installation Tip

“I first added the ram, turned on the synology, and its blue light blinked constantly. I waited for like 15 mins and nothing happened. I tried disconnecting the ram, carefully connected it again, made sure it was well connected, and rebooted the nas. It booted up in about 3 minutes”

Make sure to push the SODIMM firmly into the slot until it clicks!

ME:

Does it make sense to replace the current SODIMM with another Timetec 4GB SODIMM so they’re both the same?

CLAUDE:

Short Answer: No, it’s not necessary

The DS918+ doesn’t require matched memory pairs, and mixing brands works fine.

Why Matching Isn’t Important Here

1. Non-ECC Memory

  • Consumer memory doesn’t need matching like server ECC RAM
  • The DS918+ memory controller handles mixed modules well

2. Real User Experience

  • “Crucial CT25664BF160B DDR3L (2 x 4GB) works fine in a DS918+, DSM 7.2.1-69057 Update 7. No Warnings.”
  • Many users successfully mix Synology + aftermarket RAM

3. Cost vs Benefit

  • Extra $35 for essentially no performance gain
  • Your workload (development/containers) won’t notice any difference

When Matching MIGHT Matter

Only consider matching if:

  • You’re extremely OCD about hardware symmetry
  • You find a great deal on a 2x4GB kit
  • The factory stick ever fails (unlikely)

Better Use of That $35

Instead of a second stick, consider:

  • Cat6a cables for future 10G upgrade
  • Extra rack shelf for organization
  • Save toward your next storage upgrade
  • A nice dinner 🍕

Final Recommendation

Stick with your plan:

  • Keep factory 4GB in Slot 1
  • Add Timetec 4GB in Slot 2
  • Save the $35
  • Enjoy your 8GB total RAM

The DS918+ will run perfectly fine with mixed memory brands!

ME:

I currently have the 2 4TB WD 4TB Red Pro NAS HDDs configured in a RAID 0 configuration. If I want to put that into a RAID 0 configuration then I assume I have to make sure I have enough disk space so I don’t lose any data

CLAUDE:

⚠️ Wait - Did You Mean Change FROM RAID 0?

I think you meant changing from RAID 0 to RAID 1, right?

Current RAID 0 Setup

With 2x 4TB in RAID 0:

  • Usable space: 8TB (both drives combined)
  • No redundancy (if one drive fails, you lose everything!)

To Convert to RAID 1

You’d get:

  • Usable space: 4TB (mirrored)
  • Full redundancy (can survive 1 drive failure)

Critical Question: How Much Data Do You Have?

Check your current usage in DSM:

  1. Go to Storage Manager
  2. Look at your volume usage

If you’re using MORE than 4TB:

  • You’ll need to move some data elsewhere first
  • OR add the new 8TB drives first, move data there, then convert

If you’re using LESS than 4TB:

  • You can potentially convert, but…

⚠️ Important: You CANNOT Convert RAID 0 to RAID 1 Directly

Synology doesn’t support in-place RAID level changes. You’ll need to:

  1. Back up all your data
  2. Delete the RAID 0 volume
  3. Create new RAID 1 volume
  4. Restore your data

My Strong Recommendation

Since you’re buying 2x 8TB drives anyway:

  1. Keep RAID 0 for now (risky but works)
  2. Create new RAID 1 with the 8TB drives
  3. Move data from old RAID 0 to new RAID 1
  4. Then rebuild the 4TB drives as RAID 1

This way you never risk your data during the transition!

Are you currently using more or less than 4TB on your RAID 0 volume?

ME:

I meant changing from RAID 0 to RAID 1

CLAUDE:

Yes, You’re Exactly Right

To change from RAID 0 to RAID 1, you need to ensure you’re using less than 4TB of data.

Current vs Future Capacity

  • RAID 0 (current): 8TB usable
  • RAID 1 (target): 4TB usable
  • You’ll lose 50% capacity!

Check Your Current Usage

In DSM, go to:

  1. Storage Manager → Volume
  2. Check “Used” space

Three Scenarios

If Using < 4TB: ✅

  1. Back up everything (just in case)
  2. You’ll fit in RAID 1
  3. Proceed with conversion

If Using 4-8TB: ⚠️

You’ll need to:

  1. Delete/move some data to get under 4TB
  2. OR use the new 8TB drives first
  3. Move excess data to the new volume

If Using > 6TB: 🔄

Best approach:

  1. Set up new 8TB drives first
  2. Move data from RAID 0 → new drives
  3. Then convert old drives to RAID 1

Important: Synology Can’t Convert RAID 0 → RAID 1 Directly

You must:

  1. Backup all data
  2. Delete RAID 0 volume (scary but necessary)
  3. Create new RAID 1 volume
  4. Restore data

My Recommendation

Since you’re buying new drives anyway, use them as a “staging area”:

  • Install 8TB drives as RAID 1
  • Move data from 4TB RAID 0 → 8TB RAID 1
  • Rebuild 4TB as RAID 1
  • Keep important data on both volumes

How much data are you currently using on your RAID 0 volume?

ME:

Volume 1 Storage Pool 1 with 5.6 TB of 7 TB. Not sure why it’s not 5.6 of 8 TB.

CLAUDE:

Why 7TB Instead of 8TB?

This is normal! The “missing” space is due to:

  1. Marketing TB vs Actual TiB: Drives are sold in TB (1000³) but computers use TiB (1024³)
  2. Filesystem overhead: ~5-10% for formatting, metadata
  3. DSM reserved space: System partitions

Your 2x 4TB drives = ~7.27TB actual usable space ✓

The Real Problem: You Can’t Convert to RAID 1! ❌

Current data: 5.6TB
RAID 1 capacity: ~3.6TB
Shortfall: 2TB won’t fit!

Best Solution: Use Your New Drives

Since you’re buying 2x 8TB drives anyway:

Step-by-Step Migration Plan

  1. Install new 8TB drives in bays 3-4
  2. Create RAID 1 volume (~7.3TB usable)
  3. Move all 5.6TB from old volume to new
  4. Delete old RAID 0 (after verifying data!)
  5. Recreate as RAID 1 with 4TB drives
  6. Move less-critical data back if desired

Final Configuration 

Bays 1-2: 4TB RAID 1 = 3.6TB (backups, archives)
Bays 3-4: 8TB RAID 1 = 7.3TB (main storage)
Total: ~11TB usable with full redundancy

Why This is Actually Perfect

  • No risky in-place conversion
  • No data loss
  • Everything gets redundancy
  • Smooth migration with new drives
  • More total space (11TB vs current 7TB)

This confirms that 8TB drives are the right choice - they’ll hold all your current data with room to grow!

ME:

How can I view the SODIMM Memory RAM that has been factory installed from the DSM console?

CLAUDE:

How to View Memory Information in DSM

Method 1: Control Panel (Easiest)

  1. Open DSM in your browser
  2. Go to Control Panel
  3. Click Info Center
  4. Look for Memory section
    • Shows total installed RAM
    • Shows memory usage

Method 2: Resource Monitor (More Detail)

  1. Open Resource Monitor (icon in main menu)
  2. Click Performance tab
  3. Select Memory
    • Shows total memory
    • Real-time usage graphs
    • Memory type and speed

Method 3: SSH Command Line (Most Detail)

If you have SSH enabled:

  1. Enable SSH: Control Panel → Terminal & SNMP → Enable SSH
  2. SSH into your NAS
  3. Run commands:
# Show memory info
sudo dmidecode -t memory

# Or simpler:
free -h

# Check memory modules:
sudo dmidecode -t 17

This will show:

  • Memory type (DDR3L)
  • Speed (1866MHz)
  • Size (4GB)
  • Manufacturer
  • Slot location

What You’ll See

Factory DS918+ comes with:

  • 4GB DDR3L-1866 SODIMM
  • Usually Samsung or SK Hynix
  • In slot 1 (slot 2 empty)

Note

DSM won’t show detailed RAM specs in the GUI (like manufacturer or exact model). For that level of detail, you need SSH access.

Quick Check: Just go to Control Panel → Info Center - if it shows 4GB, you have the standard configuration!

ME:

How does adding another 4GB DDR3L-1866 SODIMM contribute to memory performance?

CLAUDE:

Memory Performance Impact of Adding 4GB

From 4GB → 8GB: Capacity Benefits ✓

1. More Cache for File Operations

  • DSM uses free RAM as file cache
  • More cache = faster repeated file access
  • Great for frequently accessed Docker images

2. More Breathing Room

  • DSM uses ~1.5-2GB baseline
  • Docker/containers get more space
  • Less memory pressure = less disk swapping

3. Better Multitasking

  • Run more services simultaneously
  • Indexing/thumbnails won’t slow other tasks
  • Smoother web UI responsiveness

Single vs Dual Channel: Limited Impact ❌

The DS918+ has two memory slots, but:

  • Unknown if it supports true dual-channel
  • Most NAS operations are disk-bound, not memory-bound
  • Memory bandwidth rarely the bottleneck

Real-World Performance Gains

Noticeable Improvements:

  • ✅ Docker containers start faster
  • ✅ File browsing more responsive
  • ✅ Multiple users accessing simultaneously
  • ✅ Large file transfers while doing other tasks

Won’t Really Notice:

  • ❌ Raw file transfer speeds (limited by network/disk)
  • ❌ RAID rebuild times
  • ❌ Video transcoding (CPU limited)

Your Specific Use Case

For development/home lab:

Current (4GB):
- DSM: 2GB
- Available: 2GB (tight for containers)

Upgraded (8GB):
- DSM: 2GB  
- Available: 6GB (comfortable headroom)

Is It Worth $35?

YES, because:

  • Prevents memory-related slowdowns
  • One-time upgrade, lasts the NAS lifetime
  • More important than CPU for responsiveness
  • Cheaper than any other upgrade

Think of it like:

  • 4GB = Economy car in city traffic (works, but tight)
  • 8GB = Comfortable sedan (smooth, no stress)

The performance gain isn’t dramatic, but it eliminates memory as a bottleneck. For $35, it’s the best bang-for-buck upgrade you can make!

ME:

I have 3 iSCSI targets connected to 3 LUNs. I don’t have any hosts added to manage the IQNs/WWPNs and LUN Permissions. What should I do about these? Can I clone them over to the new 8TB drives when I have them?

CLAUDE:

Your iSCSI Setup for vSphere

Those 3 iSCSI LUNs are likely your vSphere datastores! This is critical infrastructure that needs careful handling.

Current Setup Analysis

No Host Management = Open Access ⚠️

  • Your LUNs are accessible to any host that knows the target IQN
  • Fine for isolated home lab
  • Would be a security issue in production

Should You Add Host Management?

For Home Lab: Optional

  • If your lab is on isolated VLANs → probably fine as-is
  • If on same network as other devices → consider adding host IQNs

To Add Host Security:

  1. SAN Manager → Host → Create
  2. Add each ESXi host’s IQN
  3. Edit each target → Permissions → Assign specific hosts

Migrating iSCSI LUNs to New Drives

⚠️ Important: You CANNOT simply copy iSCSI LUNs!

Correct Migration Process

Option 1: Storage vMotion (Cleanest)

  1. Create new iSCSI LUNs on 8TB volume
  2. Add new datastores to vSphere
  3. Storage vMotion VMs from old → new datastores
  4. Remove old datastores
  5. Delete old LUNs

Option 2: Backup/Restore Method

  1. Shut down all VMs
  2. Back up VMs (or export OVAs)
  3. Create new LUNs on 8TB volume
  4. Create new datastores
  5. Restore VMs to new datastores
1. Install 8TB drives, create RAID 1 volume

2. In DSM:
   - Create 3 new iSCSI targets (different names)
   - Create 3 new LUNs on the new volume
   - Note the new IQNs

3. In vSphere:
   - Add new iSCSI targets to each host
   - Rescan storage adapters
   - Create new datastores (name them -NEW)

4. Storage vMotion each VM:
   - Right-click VM → Migrate
   - Change datastore only
   - Select new datastore

5. After all VMs moved:
   - Remove old datastores from hosts
   - Delete old LUNs in DSM

Pro Tips

  1. LUN Sizing: Make them slightly larger on new volume for growth
  2. Thin Provisioning: Consider thin LUNs to save space
  3. Document IQNs: Keep a spreadsheet of target IQNs and which host uses what
  4. Test First: Migrate one test VM first to verify process

What size are your current 3 LUNs? This will help determine the best migration strategy.

ME:

Each LUN’s Total Capacity reading is 1.7 TB.

CLAUDE:

Your iSCSI LUN Analysis

Current LUN Setup:

  • 3 LUNs × 1.7TB = 5.1TB allocated
  • This explains most of your 5.6TB volume usage!

Key Questions

1. How full are these datastores in vSphere?

  • Check in vSphere: Storage → Datastores
  • Look at “Used” vs “Capacity”
  • If they’re mostly empty, you can make smaller LUNs

2. Are they Thick or Thin provisioned?

  • DSM: SAN Manager → LUN → Check “Space Allocation”
  • Thick: Always uses full 1.7TB on disk
  • Thin: Only uses actual VM data

Migration Planning

New 8TB RAID 1 = ~7.3TB usable

If keeping same sizes:

  • 3 × 1.7TB LUNs = 5.1TB
  • Leaves 2.2TB for other data ✓
  • Tight but workable

Optimization Opportunities

Option 1: Right-size the LUNs

If vSphere shows:
- Datastore1: 500GB used of 1.7TB
- Datastore2: 300GB used of 1.7TB  
- Datastore3: 400GB used of 1.7TB
Total actual use: 1.2TB

Create smaller LUNs:
- New LUN1: 800GB
- New LUN2: 600GB
- New LUN3: 700GB
Total: 2.1TB (saves 3TB!)

Option 2: Switch to Thin Provisioning

  • Create as 1.7TB thin LUNs
  • Only uses actual VM space on disk
  • Can “overcommit” storage
  • Risk: Could fill up if not monitored

My Recommendation

  1. Check actual usage in vSphere first
  2. Create thin LUNs on new volume
  3. Size them 20-30% larger than current usage
  4. Monitor growth over time

Quick Check Commands

In vSphere Web Client:

  1. Click each datastore
  2. Note “Used Space”
  3. Add 30% for growth
  4. That’s your ideal new LUN size

What does vSphere show for actual used space on each datastore? This will determine if we can optimize your storage usage.

This project is for educational and home lab purposes.