RAID6 Vs RAID5 + HotSpare?

**AtW** · 29 January 2010, 20:42

Originally posted by wxman View Post

Suggestions ....

Try Areca RAID controllers...

AFAIK RAID 6 required pretty powerful processors on RAID cards, so just because controller says it supports it does not mean it will do it quickly.

Who the heck are PERC? It is some Dell branded low end controller or something? It could be the disk you know, we mainly use 3.5'', rather than 2.5''.

**wxman** · 29 January 2010, 20:55

PERC is Dells own brand RAID contoller - not sure of the actual chip set but her it is http://search.dell.co.uk/1/2/14084-d...ctors-kit.html

The Dell R610 server is a 1U rack mount - hence the 2.5" disks

I am on the server now (remote desktop) so I am limited as to what I can do.

Truth is - this server cost £4K while my home server was £1K (based on a desktop PC if you can belive that)

I might just throw a high end Adaptc raid at it to see what happens

**stek** · 29 January 2010, 21:27

For file and print wouldn't a simple mirror be more suitable?

**Cliphead** · 29 January 2010, 22:22

I'd be looking at the RAID controller as the problem. Any chance of being able to change it even on a temp basis to test?

**wxman** · 29 January 2010, 22:39

stek

Problem I have is that this server is business critical - therefore I went for an RAID 5 + hot spare or even RAID6 array - both gave duff performance.

However all the above is a mute point - disk 3 has failed in the array AGAIN RIGHT NOW

FYI Dell replaced disk 3 which went suspect today under warrently.

As of 22:15 Friday night Dell UK warrenty support is not "Open" again until Monday 09:00am WTF

Clients Del Poweredge server R610 (£4K in price) is therefore DOA and my only recomandation to the client is to postpone this weekends server install until the hardware is proven.

FYI Client has ALWAYS purchased IBM branded servers - But I recomended Dell at 2/3 the price of IAB as the first of many server refreshes. (I have 20+ servers to replace / virutal)

Client's I.T. muppets (if is is not IBM then it is not worth shagging attitude) are loving this

**stek** · 29 January 2010, 23:19

Originally posted by wxman View Post

stek

Problem I have is that this server is business critical - therefore I went for an RAID 5 + hot spare or even RAID6 array - both gave duff performance.

However all the above is a mute point - disk 3 has failed in the array AGAIN RIGHT NOW

FYI Dell replaced disk 3 which went suspect today under warrently.

As of 22:15 Friday night Dell UK warrenty support is not "Open" again until Monday 09:00am WTF

Clients Del Poweredge server R610 (£4K in price) is therefore DOA and my only recomandation to the client is to postpone this weekends server install until the hardware is proven.

FYI Client has ALWAYS purchased IBM branded servers - But I recomended Dell at 2/3 the price of IAB as the first of many server refreshes. (I have 20+ servers to replace / virutal)

Client's I.T. muppets (if is is not IBM then it is not worth shagging attitude) are loving this

Think I would have gone for simple mirror, cron'd detach, backup the detached mirror, reattach if only a file/print, raid 5 really is for slow writes, fast reads for most DB's and LDAP in my view - not file and print. (assuming Unix-based OS for cron etc)

I might be biased but I'd always go Sun/IBM/HP for this sort of thing, I've seen Dell fall over spectacularly before, more with SAN's but still an über-fük....

Sun etc, really, one throat to choke, my mantra never let me down. Dell are for PC's and lappies...

And u can ring Sun Support 24/7...

**stek** · 29 January 2010, 23:28

And if disk3 failed why didn't the hot-swap engage?

**AtW** · 29 January 2010, 23:44

Originally posted by wxman View Post

PERC is Dells own brand RAID contoller

That's white label - "own brand" means tulip, who actually created it? My bet would be on cheap low end RAID supplier ...

**PAH** · 30 January 2010, 12:39

If you don't need masses of disk storage I'd look into SSD, particularly the Intel X25-E or OCZ Vertex drives (current market leaders performance wise afaik), especially if read performance is more important than write.

SSD access times and IOPS are untouchable by mechanical drives regardless of the raid config and also cuts out all the ballaches associated with RAID, though you can RAID SSDs too if you want to go extreme.

Many other benefits of SSD over mechanical too: lower power usage (every watt counts in a rackmount server), cooler, silent (loving the OCZ Vertex in my PC

), more reliable (no moving parts), smaller (2.5").

Only downside at the moment is lack of storage capacity and price per GB. They (or a similar solid state alternative) are the future, but why wait.

http://www.infoq.com/news/2009/12/myspace-ssd

RAID6 Vs RAID5 + HotSpare?