RAID1 Question

[mike_seps]

I feel like I already know the answer, but I want to check.

 

If I want to add a HDD and create a 4TB RAID1 array, my current HDD will be reformatted to add into the array, correct? So I need to move all of my plex media off, then build the array in BIOS, then move it all back onto the drive?

 

Trying to prevent a future "oh s**t" moment if/when the original drive fails.

[IBM_THINKPAD_R51]

4 minutes ago, mike_seps said:

I feel like I already know the answer, but I want to check.

 

If I want to add a HDD and create a 4TB RAID1 array, my current HDD will be reformatted to add into the array, correct? So I need to move all of my plex media off, then build the array in BIOS, then move it all back onto the drive?

 

Trying to prevent a future "oh s**t" moment if/when the original drive fails.

80% of the time when you create a new array the controller will initialize the array meaning that the data will be lost. ive had some random raid controllers here or there be able to copy over from one drive to another but thats an edge-case...id recommend backup up your data.

[mike_seps]

Follow up - I know that matching things is best, but I'm trying not to spend another $120 on a WD Black 4TB. I am looking at the Red or Blue variants. I know red is better for NAS and, and the blue is a pretty basic desktop drive. Would the blue suffice since it's in a RAID array and not my only home for data? And would the 7200 rpm (black) paired with a 5400 rpm (red or blue) be an issue, or would it just slow the whole array down to the R/W speeds of the 5400rpm disk?

[Rivettz]

The raid 1 will fall back onto the lower speed much like how RAM does. It will be the same 5400RPM Speeds for accessing as well so you'll definitely be losing out on the speed side of the Black Drive. In my humble opinion I would scrape up the money required for a pair of Black drives to benefit from the higher speeds. Unless, You are okay with slower speeds of the Red NAS Drive 

[mike_seps]

I don't think the speed drop will hurt me that much, since it's just storage for my plex server. Originally go the black because that was where my steam library was going to live, then I decided to put that on NVMe, figured the spinny boi would be fine for streaming a movie

[BiotechBen]

13 minutes ago, mike_seps said:

I don't think the speed drop will hurt me that much, since it's just storage for my plex server. Originally go the black because that was where my steam library was going to live, then I decided to put that on NVMe, figured the spinny boi would be fine for streaming a movie

Can verify, 5400 blue is fine for Plex direct stream dvd quality. In theory it should be fine up to blu-ray quality, mine usually maxes out at about 112-125MB/S

[Electronics Wizardy]

1 hour ago, mike_seps said:

Trying to prevent a future "oh s**t" moment if/when the original drive fails.

Then you probably don't want raid, you want a backup. Much simpler to setup and use. Just get any other hdd, and setup a backup job.

[IBM_THINKPAD_R51]

1 hour ago, Rivettz said:

The raid 1 will fall back onto the lower speed much like how RAM does. It will be the same 5400RPM Speeds for accessing as well so you'll definitely be losing out on the speed side of the Black Drive. In my humble opinion I would scrape up the money required for a pair of Black drives to benefit from the higher speeds. Unless, You are okay with slower speeds of the Red NAS Drive 

that being said most hard drives cant variably change their rpm so the HDD would just access the platters less often.

[mike_seps]

15 hours ago, Electronics Wizardy said:

Then you probably don't want raid, you want a backup. Much simpler to setup and use. Just get any other hdd, and setup a backup job.

Isn't raid 1essentially a backup since its a mirror copy?

[Blue4130]

3 hours ago, mike_seps said:

Isn't raid 1essentially a backup since its a mirror copy?

No, raid is about uptime, not a backup. Take this as an example... You accidentally delete an important file. With raid, it's gone. If you had a proper backup such as a second drive either on another machine or an external drive only plugged in whe the doing the backup job, or any other valid backup such as tape, DVD or cloud, you'd be able to recover the deleted file. 

 

That's probably the most common scenario, but there are many others like ransomware or viruses. 

[cmndr]

On 9/14/2022 at 11:59 AM, mike_seps said:

Follow up - I know that matching things is best, but I'm trying not to spend another $120 on a WD Black 4TB. I am looking at the Red or Blue variants. I know red is better for NAS and, and the blue is a pretty basic desktop drive. Would the blue suffice since it's in a RAID array and not my only home for data? And would the 7200 rpm (black) paired with a 5400 rpm (red or blue) be an issue, or would it just slow the whole array down to the R/W speeds of the 5400rpm disk?

Be warned that some of the WD Red drives use SMR instead of CMR to store their data - the upshot is that it's cheaper to make but write performance can be catastrophically impacted, especially in RAID arrays.

My own strategy was to drop $35ish on 4TB drives on ebay. 2x4TB for the array and 1x4TB as a cold spare/backup. I figure this is cheaper overall and has more redundancy.

For NASes, I try to go for 5400RPM drives as they're on basically all the time and the power savings adds up. My NAS caches the most used data on the HDDs though so 99% of data requests don't even come off the HDDs so I don't care about the performance differential.