amuck-landowner

Is it worth having multiple SSD?

ICPH

Member
Hello,

on an VPS node server, is worth to buy secondary SSD into HW/SW Raid?

im asking because im not sure how it is with failure of SSD drives when comparing to HDDs

i dont need higher speed than one SSD has and also i dont need extreme redundancy, but good one into next 18 months
 
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AMDbuilder

Active Member
Verified Provider
I would ask the question what's cheaper?  Adding another SSD in Raid or Rebuilding the server because of a drive failure?

I wouldn't call this extreme redundancy, simple time savings.
 

drmike

100% Tier-1 Gogent
Depends on what this SSD is doing and workload - particularly writes.   A single drive of any type is bound to fail at random any time.

So two in perhaps RAID-1 might make good sense in this instance.

Software RAID should suffice and most decent boards support such on built in controller hardware.  I'd do it especially considering where SSDs have dipped to cost wise.
 

Criot

Member
Verified Provider
RAID isn't a replacement for taking backups, you should take backups regardless, however, in the majority of cases RAID is used for performance improvements and/or redundancy. Having RAID 1 would make your server redundant in the fact that if one drive failed, it'd still run off the other drive(s) so yes, RAID is important if uptime during a disk failure is of importance.
 

pcan

New Member
Good SSDs fails far less often than mechanical HDD. In 2 years I had only 1 drive fail (100 deployed devices - it was a firmware related failure).
There is a popular alternative solution: install a second, independent drive and schedule a periodic rsync from the primary one. If primary drive fails, there will be some data loss and downtime. But:

  • no hw or sw RAID is involved (one less thing that can go wrong).
  • to recover the system turn off the server, pull out both drives, put the secondary drive in the first drive slot, turn on the system again and do a few post-boot adjustements. Total downtime is short. Data loss may be not so nasty afterall (most contents does not change from one rsync to the next). No sw RAID issues due to half-dead disks - after a drive starts to fail, it is removed from the system. 
  • the secondary drive doubles as "poor's man backup" solution (provided you schedule the rsync once or twice a day). It is NOT a real backup, of course, but it will catch some common issues (fat finger errors etc.)
I was sceptical of this arrangement at first, my initial thought was the same as @Munzy. But, but... It is common now on industrial control systems, and the RAID card failure rate is almost the same as a SSD drive, so putting two SSDs on HW RAID 1 to enhance reliability does not make a lot of sense anyway. 
 

Munzy

Active Member
As long as you have some sort of backup. The point of the RAID is to keep at least the server online even if a drive does fail for more critical applications.
 

kunnu

Active Member
Verified Provider
I am also going to use SSD disk for my server with RAID10 config. I hope performance will be improved and server will more stable.

If you are going to setup RAID0 or 1 then also don't forget to take a backup.
 

William

pr0
Verified Provider
Why would it make a difference in backup between RAID1 and RAID10? It is essentially the same just with a stripe in it.
 

KuJoe

Well-Known Member
Verified Provider
Is this server going to be hosting any clients? If so then you NEED some sort of RAID redundancy just to protect your clients (backups are nice, but any amount of downtime from a single hard drive failure is unacceptable in 2015).

If you can't afford at least 2 SSD drives for RAID1, then you shouldn't be in business.

If you don't want to spend money on at least 2 SSD drives for your clients, then you do not care about your clients and shouldn't be in business.

If this is just a personal use server that nobody else will be using then you're fine running a single hard drive but why would you when the price of drives is so cheap and the benefit of RAID outweighs any cost savings or additional time spent configuring your server?
 
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trueman1

New Member
Verified Provider
raid 1 will slow down your ssd,

i will go with minimum 4x ssd.

if for example you will need 256GB space - it be much better (and probably cost less) to have 4x 128GB on Raid 10.

it will be very fast, and you will get the same disk space.
 
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KuJoe

Well-Known Member
Verified Provider
A RAID1 runs at the same speed as a single SSD - The CPU is no longer a limiting factor.
I was reading that RAID1 is also faster for reads but since I never use RAID1 anywhere I don't know if that is accurate or not.
 
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Husky

Verified Dog
Verified Provider
I am also going to use SSD disk for my server with RAID10 config. I hope performance will be improved and server will more stable.

If you are going to setup RAID0 or 1 then also don't forget to take a backup.
How are you a verified provider and still not know that no matter what the RAID level you use you should always back up important data ANYWAY.

Drives have this horrible habit of failing in groups, especially if they're from the same batch.
 

lbft

New Member
I was reading that RAID1 is also faster for reads but since I never use RAID1 anywhere I don't know if that is accurate or not.
In theory, since the same data is replicated across two different drives, you should be able to read from them both at the same time to double your speed.

In practice it depends on the implementation (software or hardware). Linux mdraid will, for example, spread read requests across the two drives (but any single read will only hit one drive, so don't expect dd porn). Many implementations will not.
 

Clouvider-Dom

Member
Verified Provider
Well, it can fail tomorrow or after 5 years, as with any drive. If you host anything in production you should always have at least RAID 1
 
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