Configuring a RAID 5

[lukesterboy]

Can you configure raid 5 and keep files currently on one of the drives so that the second disk inserted just mirrors the current disk with files or is this not possible and both disks have to be empty when configuring a raid?

[scottyseng]

3 hours ago, lukesterboy said:

Can you configure raid 5 and keep files currently on one of the drives so that the second disk inserted just mirrors the current disk with files or is this not possible and both disks have to be empty when configuring a raid?

Yeah, the drives have to be empty. Any RAID array needs to be initialized, so all data is lost in order to create the array.

 

Sadly if you have a lot of data like I did, I had to buy several external drives to use as a temp storage as my array got built.

 

Also, RAID5 needs at least 3 drives. RAID6 or 10 needs four. If you want full mirroring, that's RAID1 (Only need two disks).

[lukesterboy]

13 hours ago, scottyseng said:

Yeah, the drives have to be empty. Any RAID array needs to be initialized, so all data is lost in order to create the array.

 

Sadly if you have a lot of data like I did, I had to buy several external drives to use as a temp storage as my array got built.

 

Also, RAID5 needs at least 3 drives. RAID6 or 10 needs four. If you want full mirroring, that's RAID1 (Only need two disks).

 

Ah ok, thank you very helpful information. Also could i get like 1tb and 2 x 500gb for raid 5? What was this give me in total 2tb or 1tb?

[scottyseng]

Just now, lukesterboy said:

Ah ok, thank you very helpful information. Also could i get like 1tb and 2 x 500gb for raid 5? What was this give me in total 2tb or 1tb?

No, RAID limits you to the drive of the smallest size / slowest speed. So if you used those three in a RAID5 array, you'd be limited to 500GB to match the other 500GB drives.

 

It should give you around 1TB since the RAID5 would only use 1.5TB in total.

[lukesterboy]

Just now, scottyseng said:

No, RAID limits you to the drive of the smallest size / slowest speed. So if you used those three in a RAID5 array, you'd be limited to 500GB to match the other 500GB drives.

 

It should give you around 1TB since the RAID5 would only use 1.5TB in total.

 

Oh so usable data in that array is 500gb?

[scottyseng]

Just now, lukesterboy said:

Oh so usable data in that array is 500gb?

Useable data should be around 1TB. With the RAID5 / 6, it's a bit hard to tell, but usually the norm is 66% is useable.

 

Though I'd probably push you towards using something like Windows Storage Spaces...or some software RAID that lets you use the full space of all of your drive. Losing 500GB of the 1TB drive kind of sucks to be honest.

 

Also, what model and brand are these drives? Not all drives will work with RAID.

[lukesterboy]

2 minutes ago, scottyseng said:

Useable data should be around 1TB. With the RAID5 / 6, it's a bit hard to tell, but usually the norm is 66% is useable.

 

Though I'd probably push you towards using something like Windows Storage Spaces...or some software RAID that lets you use the full space of all of your drive. Losing 500GB of the 1TB drive kind of sucks to be honest.

 

Also, what model and brand are these drives? Not all drives will work with RAID.

 

Oh ok I see what you mean now so if you had 1 x 500gb 1 x 150 and 1 x 250gb it would be 450gb maximum usable ruffly? I don't actually have any drives just a question wanted to ask for when i get my server soon. Planning on buying more drives for it.

[scottyseng]

2 hours ago, lukesterboy said:

Oh ok I see what you mean now so if you had 1 x 500gb 1 x 150 and 1 x 250gb it would be 450gb maximum usable ruffly? I don't actually have any drives just a question wanted to ask for when i get my server soon. Planning on buying more drives for it.

Yeah, it would be. And out of that maximum usable, RAID5 / 6 take roughly 1/3 of it (It can be more or less), so you'd be left with 300GB of usable storage (and in actual use, it's roughly 279 Gibibytes (What your PC can actually use).

 

If you can though, I would push for four drives and run RAID6. I used to run RAID10, but losing half the storage was a bit too painful.

[lukesterboy]

Just now, scottyseng said:

Yeah, it would be. And out of that maximum usable, RAID5 / 6 take roughly 1/3 of it (It can be more or less), so you'd be left with 300GB of usable storage (and in actual use, it's roughly 279 Gibibytes (What your PC can actually use).

 

If you can though, I would push for four drives and run RAID6. I used to run RAID10, but losing half the storage was a bit too painful.

 

Damn usable space really drops with all raiding and formatting. Lol. What does a raid 6 do? 2 + 2?

[Mikensan]

Your use should dictate the raid / fault tolerance. If this is going to be purely for backups then go for the simple Raid 5, as technically you should already have the data on the sources. If this is going to be a NAS where only a single copy resides then you want something more, either a Raid6 or Raid10 if you need redundancy with speed. If you absolutely cannot afford (afford being a double entendre here) to lose data be it to corruption or drive failure you want to start looking in to file systems that use checksum and offer more raid features. The reason there's no 1 real answer to which raid you should use is because they all serve different purposes.

[scottyseng]

2 hours ago, lukesterboy said:

Damn usable space really drops with all raiding and formatting. Lol. What does a raid 6 do? 2 + 2?

RAID6 is like RAID5, it spreads parity across all disks, but you can lose any two RAID6 drives, where you can only lose one drive with RAID5.

 

Yeah, tell me about the space loss...I have six 4TB WD Reds in RAID6, 24TB total capacity, and only 14.533TB is really useable. Eight 4TB WD Re drives, 32TB total, is 21.829TB useable. Each 4TB drive is roughly 3.639TB that's really useable. Just a fyi for you to make yourself some headroom when using RAID 5, 6, and especially RAID10 (Where you lose even more space).

 

That being said, RAID isn't a backup, make sure you get a proper external drive to backup your stuff to.

 

Also, depending on your RAID controller, onboard or dedicated hardware card, not all RAID cards support 5 and 6. The onboard motherboard sometimes usually only support RAID 0 and 1 on the entry boards. You have to double check or go with a software solution.

[lukesterboy]

4 hours ago, scottyseng said:

RAID6 is like RAID5, it spreads parity across all disks, but you can lose any two RAID6 drives, where you can only lose one drive with RAID5.

 

Yeah, tell me about the space loss...I have six 4TB WD Reds in RAID6, 24TB total capacity, and only 14.533TB is really useable. Eight 4TB WD Re drives, 32TB total, is 21.829TB useable. Each 4TB drive is roughly 3.639TB that's really useable. Just a fyi for you to make yourself some headroom when using RAID 5, 6, and especially RAID10 (Where you lose even more space).

 

That being said, RAID isn't a backup, make sure you get a proper external drive to backup your stuff to.

 

Also, depending on your RAID controller, onboard or dedicated hardware card, not all RAID cards support 5 and 6. The onboard motherboard sometimes usually only support RAID 0 and 1 on the entry boards. You have to double check or go with a software solution.

 

Ok thanks for all that info! As for the raid card in getting an HP ProLiant DL380 G5 tomorrow, old used one, it says it has a raid card of some sort I think it's the "HP Smart Array P400"

[lukesterboy]

5 hours ago, Mikensan said:

Your use should dictate the raid / fault tolerance. If this is going to be purely for backups then go for the simple Raid 5, as technically you should already have the data on the sources. If this is going to be a NAS where only a single copy resides then you want something more, either a Raid6 or Raid10 if you need redundancy with speed. If you absolutely cannot afford (afford being a double entendre here) to lose data be it to corruption or drive failure you want to start looking in to file systems that use checksum and offer more raid features. The reason there's no 1 real answer to which raid you should use is because they all serve different purposes.

 

Ok thanks. I didn't know raid 10 gives you more speed that's handy to know. As for how important my data is, to me it's important but it's not stuff that I can't get again. Things like music and videos I could re-download and pictures and personal videos I backup on an external drive anyway.

[scottyseng]

23 minutes ago, lukesterboy said:

Ok thanks for all that info! As for the raid card in getting an HP ProLiant DL380 G5 tomorrow, old used one, it says it has a raid card of some sort I think it's the "HP Smart Array P400"

Ah, I see. That should work fine.

 

Yeah, RAID6 will get you more sequential speeds (When dealing with large files) and RAID10 will get you more random IO speed (like tiny files for your programs / OS). I personally changed to RAID6 because you get to use 2/3 of the space only 1/2 with RAID10 or 1.

 

Yeah, definitely keep a eye on backups.

 

You do plan on putting that in a closet right? 2U servers aren't exactly quiet for the most part.

[lukesterboy]

Just now, scottyseng said:

Ah, I see. That should work fine.

 

Yeah, RAID6 will get you more sequential speeds (When dealing with large files) and RAID10 will get you more random IO speed (like tiny files for your programs / OS). I personally changed to RAID6 because you get to use 2/3 of the space only 1/2 with RAID10 or 1.

 

Yeah, definitely keep a eye on backups.

 

You do plan on putting that in a closet right? 2U servers aren't exactly quiet for the most part.

 

So is RAID 10 good to run an OS on then? And the server location. Um, I was going to put it under my desk, want to run it 24/7 but like you say I'm guessing it's going to be loud, I was hoping either I can tune down the fans or something. If not I'm going to have to put it in my loft and run power and ethernet up to it since I don't have a closet/cupboard I live in a smallish flat.

[scottyseng]

21 minutes ago, lukesterboy said:

-snip-

Yeah, but I personally wouldn't use such a large RAID for a OS (a tad overkill). The norm for a server is RAID1 with two drives...but since this is a home use server, I wouldn't bother with redundant drives for the OS since this isn't exactly a critical thing for a home server.

 

I'd just use a RAID array for the data only and be done with it. I'd just buy a single SSD for the server OS itself and run it straight off of the motherboard and leave the SSD hanging in the chassis (That's how I have mine at the moment).

 

Well, it depends on the model of server. Some do turn down, but my SuperMicro 4U...only run at 50% fan and up, and you can't override the fan speeds using software or the BIOS...

[lukesterboy]

9 hours ago, scottyseng said:

Yeah, but I personally wouldn't use such a large RAID for a OS (a tad overkill). The norm for a server is RAID1 with two drives...but since this is a home use server, I wouldn't bother with redundant drives for the OS since this isn't exactly a critical thing for a home server.

 

I'd just use a RAID array for the data only and be done with it. I'd just buy a single SSD for the server OS itself and run it straight off of the motherboard and leave the SSD hanging in the chassis (That's how I have mine at the moment).

 

Well, it depends on the model of server. Some do turn down, but my SuperMicro 4U...only run at 50% fan and up, and you can't override the fan speeds using software or the BIOS...

 

Ok. Well, maybe I'll have to get an SSD for my server and plug it inside then. I can just zip tie it down inside or something. Ok, what dB does you server run at? On hp's website it says the operating is 44 dB. That isn't that loud? Is it.

[scottyseng]

Just now, lukesterboy said:

Ok. Well, maybe I'll have to get an SSD for my server and plug it inside then. I can just zip tie it down inside or something. Ok, what dB does you server run at? On hp's website it says the operating is 44 dB. That isn't that loud? Is it.

Ah, well, I got so tired of the fan noise of my server that I actually took out all of the stock server fans and just have a bunch of be quiet fans inside of it, which dropped the noise a fair bit...My server was running at 48 dB, now it's more like 42dB. However, after all of that work, my 2U UPS runs at 48dB...and it's really noticeable.

 

Ah, it depends on your taste of loud...44dB isn't too bad though.

[leadeater]

On 8/17/2016 at 8:35 PM, lukesterboy said:

Ok. Well, maybe I'll have to get an SSD for my server and plug it inside then. I can just zip tie it down inside or something. Ok, what dB does you server run at? On hp's website it says the operating is 44 dB. That isn't that loud? Is it.

 

On 8/17/2016 at 8:39 PM, scottyseng said:

Ah, well, I got so tired of the fan noise of my server that I actually took out all of the stock server fans and just have a bunch of be quiet fans inside of it, which dropped the noise a fair bit...My server was running at 48 dB, now it's more like 42dB. However, after all of that work, my 2U UPS runs at 48dB...and it's really noticeable.

 

Ah, it depends on your taste of loud...44dB isn't too bad though.

Anything around the 40dB mark at night is actually rather loud. I built a custom wooden box for my server so its completely covered and also off the ground. It draws air in from the front bottom and blows out the back bottom so it's extremely quiet.

 

I actually used to sleep with an old 14 bay rackmount parallel SCSI disk shelf in my room and omg that was very very loud, no idea how loud but easily over 50 dB.

[scottyseng]

14 minutes ago, leadeater said:

 

Anything around the 40dB mark at night is actually rather loud. I built a custom wooden box for my server so its completely covered and also off the ground. It draws air in from the front bottom and blows out the back bottom so it's extremely quiet.

 

I actually used to sleep with an old 14 bay rackmount parallel SCSI disk shelf in my room and omg that was very very loud, no idea how loud but easily over 50 dB.

I probably should do the same with making a custom wooden box.

 

Yeah, I've think I've gotten to 48dB in my room due to the UPS / server combined. 50dB+ is getting to my sanity limits though, no idea how you managed that.

[lukesterboy]

3 hours ago, leadeater said:

 

Anything around the 40dB mark at night is actually rather loud. I built a custom wooden box for my server so its completely covered and also off the ground. It draws air in from the front bottom and blows out the back bottom so it's extremely quiet.

 

I actually used to sleep with an old 14 bay rackmount parallel SCSI disk shelf in my room and omg that was very very loud, no idea how loud but easily over 50 dB.

 

Could you attach some pictures of said wooden box so I could get an idea of what to build because I think I might do this for my server too, how much does it reduce the sound, can you sleep at night with it on its that quiet? Also do you need to vent it out through your brickwork or anything that is hassle?

[leadeater]

14 hours ago, lukesterboy said:

Could you attach some pictures of said wooden box so I could get an idea of what to build because I think I might do this for my server too, how much does it reduce the sound, can you sleep at night with it on its that quiet? Also do you need to vent it out through your brickwork or anything that is hassle?

Will get some photos when I can, also my server is a tower not rackmount (has rack option) but doesn't make much difference. Either build a wide box or put rackmount on it's side and make a taller box. Will make more sense when you see it.

 

The server is actually in an attached garage but being an IBM x3500 M4 it's fans are really noisy, even when bios is set to quiet mode. Once it's in the box and the cover is on it's near silent, you have to stop and really listen to hear it 3-4 meters away. What makes it so quiet is the air in and out face down at the ground, I have filters (rags etc ) at the front to stop dust getting sucked in.

[lukesterboy]

1 hour ago, leadeater said:

Will get some photos when I can, also my server is a tower not rackmount (has rack option) but doesn't make much difference. Either build a wide box or put rackmount on it's side and make a taller box. Will make more sense when you see it.

 

The server is actually in an attached garage but being an IBM x3500 M4 it's fans are really noisy, even when bios is set to quiet mode. Once it's in the box and the cover is on it's near silent, you have to stop and really listen to hear it 3-4 meters away. What makes it so quiet is the air in and out face down at the ground, I have filters (rags etc ) at the front to stop dust getting sucked in.

Damn, sounds awesome. All figured out with the dust extraction :D. Yep when you can,  please do share. 

 

Better leave the thread here, not really on the topic of Raids now.