Spare HDD. Now, what to do with it?

[PunchCardBoss]

I’ve got a DS220+ with 4Tb x2 single volume running RAID 1. DSM 7.2.2 – update 2 is running. No performance issues. Both production drives report Good. Running Data Scrubbing once a month. No snapshots (don’t really need them as the NAS is not used as the primary data source).

Packages:

• Photos
• Surveillance Station managing 6 POE cameras
• Drive Sync 2 PCs
• File Manager for all LAN device backups
• Chat (future)

All NAS data is backed up to an SSD and stored in 3 fire-resistant pouches (one inside of another) all inside a Fire Proof safe.

So, I got a spare Seagate IronWolf ST4000VN006 HDD just in case one of my (2) ST4000VN008 production units dies. This new IronWolf HDD is slightly different: 2 platters instead of 3 and 256Mb cache instead of 64Mb. The drive speed of the 006 is a bit slower at 5400 RPM, but its data density is higher. All that to say other forum posts say it is okay to mix the 2 designs.

So, what now. I could just put the spare in the closet and wait for a production HDD to fail, or…..? I think there may be some better options…..

I know I can pull one of the production drives out of my NAS and put the new 006 in its place and let my NAS create a new mirror. Then pull it out and put the 008 HDD back in. Could/should I do that every month to create a semi-hot spare?

I could also get a SADA III external enclosure for about $25 and use it as a hyper-backup destination.

Or ?????

What would you do?
What are best practices?

 

[Rusty]

Could/should I do that every month to create a semi-hot spare?

Imho, no. Each time you do that the array will rebuild stressing both drives across the board.

An external backup sounds like a better solution to me and it will still be a “hot” spare that you can attach to any device, not just the NAS (depending on how it will be configured).

 

[PunchCardBoss]

Each time you do that the array will rebuild stressing both drives across the board.

Thanks @Rusty . I thought this could be an issue. But then, I started 'second guessing' myself because this is a RAID-1 setup - the simplest of all RAIDs - writing to both drives simultaneously, essentially a mirror - not much of an "array".

I did some additional reading on other forums to get a better understanding of how a RAID-1 replacement HDD gets rebuilt. I did see some posts that suggested different systems and OSs handle things differently, but nothing definitive for Synology RAID-1.

So I am still left wondering..... If a new drive is simply Reading from the existing drive and Writing to the new drive, then the stress level doesn't seem that high (relative to a hyper-backup). Then again, I trust your IMOH more than my guess.

Perhaps others with more insight will provide some clarity.

 

[PunchCardBoss]

Well, after doing some additional research, removing a healthy drive from a Synology NAS and then adding it back into the RAID-1 array is POSSIBLE but NOT PRACTICAL.

It does appear that a healthy drive can be “deactivated” and removed. But that drive cannot just simply be re-added to the array without going through the “rebuilding” steps and time.

Here are some of the sources I found that may be helpful for others.

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Repair a Storage Pool - Repair a Storage Pool | DSM UC - Synology Knowledge Center

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“In my own experience with Synology and other raid controllers on Windows, it takes about 12-13 hours to rebuild a 2Tb drive and about the double for a 4Tb drive.” Source: Louis-S @louis_s Jan 17, 2021 - https://community.synology.com/enu/forum/1/post/140325

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“Conclusion: Adding a once removed drive into a Synology NAS with DSM worked for me, at least after removing all partitions before inserting the drive.” Source: by Cellcon Aug 23, 2021 - https://superuser.com/questions/1640640/rebuild-raid-with-old-hdd-in-synology-nas

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“The Storage Manager | Repair option (so it says) wipes the entire drive which would seem to me to be a sledge hammer approach to re-syncing a mirror set that had only been out of sync for a few minutes.” Source: Jeremy @jeremy_lloyd Jun 06, 2020 - https://community.synology.com/enu/forum/1/post/134626

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What is SHR? And what is the difference between Synology Hybrid RAID and Ordinary RAID? (Last updated on 17 Feb 2021) - https://nascompares.com/2016/07/06/what-is-shr-and-what-is-the-difference-between-synology-hybrid-raid-and-ordinary-raid/

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How to repair a RAID with a new drive by NAScompares (Nov 9, 2018) - https://youtu.be/jyyZxywRNdg?si=OMKPaBqQVdKEukZW

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Synology RAID 1 Rebuilding
Based on the provided search results, here’s a comprehensive guide on rebuilding Synology RAID 1:

Pre-requisites

1. Backup your data: Before rebuilding the RAID, ensure you have a complete backup of your data to an external drive or cloud storage.
2. Identify the failed drive: Determine which drive failed and needs replacement.

Step-by-Step Rebuilding Process

1. Remove the failed drive: Physically remove the failed drive from the Synology NAS.
2. Initialize the replacement drive: Use a disk utility (e.g., Windows Partition Manager) to wipe all partitions from the replacement drive.
3. Insert the replacement drive: Place the initialized replacement drive into the Synology NAS.
4. Start the RAID repair: Go to the Synology Storage Manager, select the degraded RAID 1 volume, and initiate the repair process.
5. Wait for the rebuild: The Synology NAS will automatically rebuild the RAID 1 volume using the remaining good drive and the new replacement drive.

Source: Brave browser AI-generated answer. Please verify critical facts. - https://search.brave.com/search?q=synology+raid+1+how+rebuilding&source=desktop&summary=1&conversation=26922c63fd543bef9b164f​

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Synology Healthy Drive Issue​

If you have deactivated a healthy drive in your Synology NAS and want to re-add it, follow these steps:

1. Ensure the drive is healthy: Before re-adding the drive, verify its health status using Synology’s Storage Manager. Go to HDD/SSD, select the drive, and check its Health Info. If the drive is still showing as healthy, proceed with re-adding it.
2. Deactivate the drive (if necessary): If the drive was previously deactivated, you’ll need to reactivate it before re-adding it. Go to Storage Manager > HDD/SSD, select the drive, and click Action > Reactivate.
3. Remove the drive (if necessary): If you previously removed the drive, reinsert it into the NAS enclosure. Make sure it’s securely seated and powered on.
4. Re-add the drive: Go to Storage Manager > HDD/SSD, and click Add. Select the reinserted drive from the list of available devices. Follow the wizard to complete the re-add process.
5. Rebuild the volume (if necessary): If the drive was previously part of a RAID configuration, you may need to rebuild the volume. Go to Volume > Manage, select the volume, and click Repair. Follow the wizard to rebuild the volume and redistribute data across the drives.

Source: Brave browser AI-generated answer. Please verify critical facts. - https://search.brave.com/search?q=synology+re-add+healthy+drive&source=web&summary=1&conversation=955732fd89738d8b6854f9​

 

[Telos]

Of course ... "any time one removes a drive from an active array, that drive is no longer in sync with the array". (excerpted from, RAID 101, lecture 4)

 

[Coop777]

Imho, no. Each time you do that the array will rebuild stressing both drives across the board.

An external backup sounds like a better solution to me and it will still be a “hot” spare that you can attach to any device, not just the NAS (depending on how it will be configured).

Agreed. The NAS itself is also not designed for continuous drive swapping - in addition to more stress on the array with rebuilds, you run the risk of possibly damaging the backplane connectors.

 

[PunchCardBoss]

The NAS itself is also not designed for continuous drive swapping

Tks @Coop777 @Telos and @Rusty . Never having played with RAID systems before my 220+, I was unaware of the implications of removing a drive.

Tks for the feedback and education.

Fortunately, I have a SADA HDD case with USB-3. So I have used the new 4Tb as a HyperBackup of the entire system and data. This one will go into the fire resistant pouches inside the fire proof safe (along with my other monthly data backups).

If/When one of my 2 NAS drives go out, I will use the new 4Tb as a replacement.