Raid 6 or Raid 10 or more disks?

[TwistedHelixis]

Hi, Just ordering a new server for a primary school. Its going to be their main server (HOST, DC VM, DATA VM).

 

I normally go for Raid 10 but wondered if I should go with Raid 6. I have never used RAID 6, so a little nervous about going this direction.

 

Got a quote for a DELL T440 with 10x600gb SAS drives.

 

Current server is using 2TB of space

 

10x600gb in RAID 10 = 3TB > Not sure 1TB of space will be enough for the next 5 years, as I might also use this server for Cloud backup.

 

10x600gb in RAID 6 = 4800TB > This does give me way more space

 

So my options are, get even more disks and go with RAID 10 or just go RAID 6

Whichever option I choose I am going to need another disk as I like to also have a hot spare.

 

Any thoughts?

 

Sam

[localzuk]

600GB disks are very small these days to be honest, and overpriced.

 

We switched from SAS drives to SATA SSDs 5 years ago and have had zero issues. A Samsung PM883 1.92TB is about £290, compared to Dell's list price of more than £400 for a 600GB SAS drive!

[Mako]

I agree with @localzuk regarding size and SAS vs SSD (we also have a Hyper-V host using the PM883 drives and it's been brilliant), but that aside;

 

Given you've mentioned it's the main server, I would be inclined to opt for RAID 10. While you lose half your capacity, the performance over RAID 6 will be noticeable. You'll be needing that write performance especially if running virtual machines.

 

RAID 6 is good for non-critical general data storage, backup, archiving etc as it has greater fault tolerance but much slower write performance, and much longer rebuild times if there's a failure. Given that there should be good backups in place, the level of fault tolerance of R6 over R10 shouldn't be of *too* much concern.

[supportman]

Putting spinning rust in a new server these days is very rare. Definitely go SSD.

[PyROm]

Out of interest, what server make/model are you using that take the Samsung PM883 1.92TB ? I have been looking at replacing a server and the storage costs of Dell and HP are huge.

[Norphy]

Irrespective of storage medium, I would only use RAID6 in a backup server, where write performance doesn't matter and where storage space is paramount. If this server is a virtualisation host, use RAID 10. Storage performance will be much better and it will still be able to tolerate two disk failures.

[FragglePete]

Hi, Just ordering a new server for a primary school. Its going to be their main server (HOST, DC VM, DATA VM).

 

I normally go for Raid 10 but wondered if I should go with Raid 6. I have never used RAID 6, so a little nervous about going this direction.

 

Got a quote for a DELL T440 with 10x600gb SAS drives.

 

Current server is using 2TB of space

 

10x600gb in RAID 10 = 3TB > Not sure 1TB of space will be enough for the next 5 years, as I might also use this server for Cloud backup.

 

10x600gb in RAID 6 = 4800TB > This does give me way more space

 

So my options are, get even more disks and go with RAID 10 or just go RAID 6

Whichever option I choose I am going to need another disk as I like to also have a hot spare.

 

Any thoughts?

 

Sam

Have a look for a Dell cancelled order - usually at massively reduced prices with more storage than you'll ever need. We got one in last year and it's an absolute animal for less than configuring one ourselves. https://www.deane247.com/ get these on a regular basis.

 

Pete

[localzuk]

Out of interest, what server make/model are you using that take the Samsung PM883 1.92TB ? I have been looking at replacing a server and the storage costs of Dell and HP are huge.

We have ours in QNAP rackmount NASs. Specifically TVS-EC1580MU-SAS-RP, with 10GbE network cards. We have 2 of them, with 10 of the SSDs in each.

 

All in RAID6. The performance difference between SSD and legacy disks is considerable, that RAID10 is not necessary. We have 40+ VMs running our 6 schools from this setup without the slightest performance issue.

Edited November 3, 2020 by localzuk

[Mako]

Storage performance will be much better and it will still be able to tolerate two disk failures.

 

Up to two disks is an important point to add. It depends which disks have failed. If you have the minimum of a 4 disk array, you could lose disk 1 and 3 and be fine, but lose disk 1 and 2 and you're knackered.

 

@PyROm I have 2x SuperMicro 213A-R740LPB Server Chassis which are acting as my Hyper-V hosts.

[Jaan]

I agree with above points. I wouldn't consider "spinning rust" anymore. The performance difference is day and night.

 

We use storage spaces here (S2D in a cluster mind). But what if you had 2 ssd in raid 1 for the OS and a set of 4/6/8 SSD/nvme disks in a storage spaces group for the other stuff?

 

Just thinking out loud mind. But i would also add that RAIDs aren't a alternative to good backups, we've had controllers fail in the past which was fun.