What RAID level should I use?

cyclone3d

[H]F Junkie
Joined
Aug 16, 2004
Messages
13,607
I have plans to set up a public ftp site mostly for retro and vintage drivers, manuals, and other software.

I have a couple different options for servers but the specifics of those are not all that important at this point.

I will also be using this server for local backups / data sharing and will hopefully be able to back up to the cloud with my current backup plan instead of having to backup everything to one desktop and then to the cloud.. Still have to test that out.

In any case, the disks I will be starting out with will be 12x 3TB SAS drives.

I've probably only got maybe 5-6TB of data at this point so the RAID using up a few disks for parity will not be an issue.

The OS for this server will be running off of disks independent from the RAID set.

I've been looking at RAID 5, 50, 6 and 60.

Other possible relevant information is that I will be running a 10Gb network for my 2 main computers and this server. I may add a VM host connected at 10Gb as well.

For those of you who have a lot of experience with RAID setups, what would you recommend?
 

likeman

Gawd
Joined
Aug 17, 2011
Messages
708
I have plans to set up a public ftp site mostly for retro and vintage drivers, manuals, and other software.

I have a couple different options for servers but the specifics of those are not all that important at this point.

I will also be using this server for local backups / data sharing and will hopefully be able to back up to the cloud with my current backup plan instead of having to backup everything to one desktop and then to the cloud.. Still have to test that out.

In any case, the disks I will be starting out with will be 12x 3TB SAS drives.

I've probably only got maybe 5-6TB of data at this point so the RAID using up a few disks for parity will not be an issue.

The OS for this server will be running off of disks independent from the RAID set.

I've been looking at RAID 5, 50, 6 and 60.

Other possible relevant information is that I will be running a 10Gb network for my 2 main computers and this server. I may add a VM host connected at 10Gb as well.

For those of you who have a lot of experience with RAID setups, what would you recommend?
disks over 2TB in size should be RAID6 (if more then 4 disks) or RAID 10 (for 4 disks)

RAID 6 can handle 2 disk failures or 1 disk rebuilding and then a data error (it just keep on going)

with RAID 5 if you replace a disk or a failed disk you have zero redundancy when its rebuilding or waiting for replacement disk and if you get an data error when rebuilding or a second disk fail you lose the array (with dell hardware raid cards it can still keep the array up with a broken RAID array as long as the disk is still functional, but you must remake it to remove the hole punched array)

with that many disks i recommend 1 disk to be hot spare with RAID6 so it automatically rebuilds from hot spare in the event a predicted disk fail happens or a failed disk (make sure you setup email notification)

RAID5 should not be used for more than 5 years ago as there is always a chance of a double fault (software raid and hardware raid can keep up perfectly fine with RAID6 or Z2 free/truenas raid) if you getting a synology use SHR 2 raid
 

mwroobel

Supreme [H]ardness
Joined
Jul 24, 2008
Messages
4,994
Where will the box be located? Will you have easy access to replace drives? I would recommend a minimum of double parity RAID, and mirrored double parity if you will not have easy access to the box. Have a hot spare and a cold spare setup as well for the eventual failure(s). you haven't mentioned an OS so I don't know if you have Hardware or Software RAID planned.
 

cyclone3d

[H]F Junkie
Joined
Aug 16, 2004
Messages
13,607
Ok. File server hardware will probably be a Dell DL3200 / R720xd with a PERC H710P controller.

Not sure if I want/need to upgrade the CPUs. They currently have dual E5-2609 CPUs.

Edit... 2.4Ghz quads with no turbo boost... blech. I think I am going to get some faster CPUs.

I will have easy access to replace drives. I'll probably keep a couple spares on hand.
 
Last edited:

likeman

Gawd
Joined
Aug 17, 2011
Messages
708
Ok. File server hardware will probably be a Dell DL3200 / R720xd with a PERC H710P controller.

Not sure if I want/need to upgrade the CPUs. They currently have dual E5-2609 CPUs.

Edit... 2.4Ghz quads with no turbo boost... blech. I think I am going to get some faster CPUs.

I will have easy access to replace drives. I'll probably keep a couple spares on hand.
as long as the disk are not 4kn drives they will work fine with that dell server (they only work with 512 or 512 emulated disk which is most disks, 4kn is a lot rare and normally the disk itself will say 4kn on the label itself, you may have problems if they are 4kn disks) i am aware that 8TB disks work with this raid card

if you set it up as RAID 6 with 10 drives and leave the last 2 configured as hot spare whenever a drive becomes predicted fail or just flat out fails it move/rebuild to hot spare, its fully automatic no user action is required ( if its a predicted fail it will move the data off the predicted fail disk before it fails so it does not have to use parity,, But if the disk flat out fails it will have to rebuild from parity to the hot spare witch is slower and hits all disks with load)

by default unless you change it when you replace the failed disk the dell raid card will auto move the data back from the hot spare to the original slot (the new disk you replaced) and return hot spare disk back to a hot spare idle status (again this is fully automatic once you insert the new disk)

make sure you install OMSA (as that gives you whole server overview not just the raid) and megaraid as both have email options to email you in an event somthing happens the OMSA is more important as it gives you whole server warnings (you need to edit the ini settings to turn off the Non Dell Disk warning triangle or you constantly have a yellow triangle)

https://www.dell.com/community/Powe...non-critical-quot-warning/td-p/4401070/page/2

to clear the non certified dell hard drives warning go to
C:\Program Files\Dell\SysMgt\sm\stsvc.ini
and change
NonDellCertifiedFlag=no
restart server
if the dell R720xd is the 12x 3.5 bay with 2x 2.5 rear bay you got nice server there,, RAID1 for the 2 SSDs and 12 for the RAID6 10+2 (2 hotspare) do make sure you have the BBU battery for the raid card and its functional or write speeds will be slow (use megaraid to look at battery as OSMA only says battery ok or ok Learning)
 
Last edited:

cyclone3d

[H]F Junkie
Joined
Aug 16, 2004
Messages
13,607
as long as the disk are not 4kn drives they will work fine with that dell server (they only work with 512 or 512 emulated disk which is most disks, 4kn is a lot rare and normally the disk itself will say 4kn on the label itself, you may have problems if they are 4kn disks) i am aware that 8TB disks work with this raid card

if you set it up as RAID 6 with 10 drives and leave the last 2 configured as hot spare whenever a drive becomes predicted fail or just flat out fails it move/rebuild to hot spare, its fully automatic no user action is required ( if its a predicted fail it will move the data off the predicted fail disk before it fails so it does not have to use parity,, But if the disk flat out fails it will have to rebuild from parity to the hot spare witch is slower and hits all disks with load)

by default unless you change it when you replace the failed disk the dell raid card will auto move the data back from the hot spare to the original slot (the new disk you replaced) and return hot spare disk back to a hot spare idle status (again this is fully automatic once you insert the new disk)

make sure you install OMSA (as that gives you whole server overview not just the raid) and megaraid as both have email options to email you in an event somthing happens the OMSA is more important as it gives you whole server warnings (you need to edit the ini settings to turn off the Non Dell Disk warning triangle or you constantly have a yellow triangle)

https://www.dell.com/community/Powe...non-critical-quot-warning/td-p/4401070/page/2



if the dell R720xd is the 12x 3.5 bay with 2x 2.5 rear bay you got nice server there,, RAID1 for the 2 SSDs and 12 for the RAID6 10+2 (2 hotspare) do make sure you have the BBU battery for the raid card and its functional or write speeds will be slow (use megaraid to look at battery as OSMA only says battery ok or ok Learning)
I have two with almost the same exact config... The model numbers are 720xd and DL2300 (not DL3200.. that doesn't exist). They really are the same exact system... they were just sold/packaged differently.

Yes, they have the 12x drive bays up front and the 2x 2.5 bays in the back.

These were recently decommissioned and each has 6x 3TB SAS drives already.

I also have another one, the DL2200 which has 12x bays up front and 2x 2.5 bays inside the case. It is 1366 instead of 2011 though.
 

Ready4Dis

[H]ard|Gawd
Joined
Nov 4, 2015
Messages
1,761
Are you going to do backups and such or do you need mirroring? As mentioned, I would avoid RAID 5, especially with as many drives as you're talking, RAID 6 will be much safer with only a few % more in lost space. RAID 50 and 60 are way overkill if you have any sort of backups. 10gbe is easy to saturate... I can saturate it with my 6 2.5" HDD's in my R710 with RAID 10. But don't get to hung up on MB/s if you're doing a server, you want to be looking at IOPS if you're going to have multiple users. My drives are 7200rpm standard SATA drives. I imagine your SAS drives will have absolutely no problems in any configuration to saturate your network.

If you're doing a file serer, you are most likely talking about 95% reading from the disks with only uploading once in a while (or at least much less often). So, having slower write performance with RAID 6 than any X0 (mirrored) won't really have much effect most of the time, but for sure raid 10 would have better performance, but you lose 1/2 your storage. RAID 6 is a good compromise, especially for mostly sequential reads. From your requirements though, with RAID 10 you'd still have 18TB of space, which is about 3x what you said you'd need. This would be the most performance for random IO with multiple users (give you the most IOPS). I would hazzard a guess that you won't really notice a difference between them for mostly seqential read ops with a 10gbe limit.

ps. if you have a bit more information on what you think the work load will be (download vs upload, # of users, etc) it may help a bit. Right now, I would only be thinking RAID 6 and 10. 10 only has to read a single disk while rebuilding, while 6 has to read all disks to regenerate the broken disk. If you have the time, you can setup the disks both ways and then test how many IOPS you get on both and see if they will meet your needs.
 

LFaWolf

Gawd
Joined
Aug 7, 2016
Messages
674
Am I reading this right - are you setting up a publicly accessible ftp server that will also house backup of your personal data?
 
Top