Best RAID for Performance? 1

[TamedTech]

Hello Chapps,

About to carry out a network install ... Its for a radio statio and the broadcast systems access all the files from the server.

I need to optimsie performance of the server for this, what are your suggestions?

I am looking to inplement a RAID system, which type offers the best read/write speeds? Redundency is not a nececity but wouold be a nice feature. I look to be using an HP ML350 server and install an array of disks running at 15,000rpm as i presume these will be faster?

Not really a hardware man and needed some advice.

Thanks,

Rob

p.s. if you have any other general performance tips i would love to hear them

 

[rliebsch]

Personallly, I would use RAID5. You will take a slight (very slight) performance hit, but the resiliency from the parity stripe is worth it.

You say redundancy isn't important, but I would rather not risk it.

If you can absolutely lose the data and performance is the key, I would go RAID0.

But I have only ever used RAID0 when mirroring entire arrays...

Extra peformance tips: you can never have too much RAM.

Robert Liebsch
Stone Yamashita Partners

http://www.stoneyamashita.com/

 

[rvnguy]

TamedTech,

I have been looking at servers and have found some interesting information. It appears that Aberdeen assembles some of the fastest accces SCSI arrays at this time for a reasonable cost. Owing to the cost of SCSI drives (the 15,000 variety) but their access is blazing. I could not locate another comparison article that explained why. They all use the Intel (there are options) processors and other like items, But in short it falls on the controller used, HP uses a proprietary card, Dell uses another, and Aberdeen uses the 3Ware controller.

You might read the comparison at this link and maybe rethink your hardware, or not:

http://www.pcmag.com/article2/0,1895,1645814,00.asp

Bottom line: for 24/7 mission critical applications go with the higher cost, time proven, SCSI drives.

Hope You Find This Helpful


rvnguy
"I know everything..I just can't remember it all

 

[mrdenny]

HP uses a co-branded Adaptec card.
Dell uses a PERC controller.

The PERC drivers can be a pain to get installed. Support for the HP cards is built directly into Windows 2003.

Since this is for the broadcast system to access the files I would assume to play the songs on the air, I'd say redundency is required. What happens if the array fails and is down for the night? Will the station be off the air until the array is rebuilt? Where will the data for the array come from?

HP makes some very fast arrays. I also looked at the Aberdeen solutions and they looked good. I never got my hands on one however. You may also want to look at a NAS solution if you are looking for a file server only. Netapp makes a good NAS. It's got very high throughput. It's a fiberchannel drive solution all running RAID4 with gigs (I think) of cache on the controller card for max speed. The whole system is optomized for serving files very fast and never crashing. At a prevous job we have 4 netapps and they all had up times of over a year.

Denny
MCSA (2003) / MCDBA (SQL 2000)

--Anything is possible. All it takes is a little research. (Me)

http://www.mrdenny.com

(Not quite so old any more.)

 

[TamedTech]

Ok .. Thanks for the info guys keep it comming.

The NAS is an intresting option .. but we are working to tight budget and the server is going to be DC aswell for the domain and the 15 or so admin PC's access files on the network ... at the moment the DC is a standard PC running windows 2000 and its keeps getting real slow and crashing ... have tried a complete re-build with no joy so it must be the massuve strain on the hardware.

 

[rvnguy]

TamedTech,

I hope you found the article interesting. I concur with mrdenny's point on redundancy if for only the reason of not losing the important data that has been compiled. (some can be retreived at great expense by Co's that provide this) But a bit of investment up front can preclude this from being necessary.

I do not know the extent of the store of information that you have to deal with, but as most things go it increases in great leaps and bounds. To that point, a NAS or SAN can be investigated, choice dependant upon if the data is to live or archival, and integrated at a later time when the need becomes more critical.

If you are experiencing a slow down that is traffic induced with only 15 users, you should most definitely consider at least a dual processor replacement.
You might want to evaluate current and project future traffic and find that it could be a wise option to purchase four processor capability with the initial purchase of only two. This would provide an easier upgrade path if you anticipate the increase that might require more horse power. These are available in 2U to 4U rack mountable packages and possibly in tower cases.

Good Luck in your endeavour.


rvnguy
"I know everything..I just can't remember it all

 

[technome]

Want to compare raid adapters, benchmarks are in English....

http://tweakers.net/benchdb/suite/13

Unless your running SQL you will see little difference between 10k and 15k scsi drives.

........................................
Chernobyl disaster..a must see pictorial

http://www.kiddofspeed.com/default.htm

 

[TamedTech]

Thanks for this guys ... if i could purlple star you all i would!

RVNGUY - Thanks for clarifying that the slowdown is likey due to traffice, one fear that i have with this project is i am going to install it and still have the exact same issues.

I think RAID5 is going to be my best option on this one, and will most definatly be settling with a DUAL processor on the server, HP are giving one away free at the moment so not a hit on the budget!

The current server setup they have is very weak ... a DELL desktop PC, P4 2.4GHz, 256Mb RAM, 80Gb IDE HDD and a 10/100 network adapter ... not sure who installed this kit but i know they are tendering agianst me on the re-build ... dont think its going to be a challenge ha!

The current specs i have on the new install are roughly as follow ... HP ML350 ... Dual Xeon 3Ghz, 2GB RAM, redundant system fan, redundant PSU ... SCSI 15,000rpm RAID5 disk aray and a dual 10/100/1000 NIC.

Think this should give it enough of a kick in the teeth .. currently they have now backup or UPS installed, they are also using a stack of switches thier "IT Consultant" got from the local Staples!

Like i say ... i you guys have any other reccomendation on things that can be done as far as routing traffic and things like that are concerned it would be greatly appreciated.

Thanks,

Rob

 

[TamedTech]

Couple more things to run past you chapps.

As I say ... the broadcast PC is reading audio files in mp3 format from the server ... on a regular basis they use one of the client to RIP music from disk on the server ... will this new setup cope with that sort of load?

I could also use some advice on setting up a RAID5 config .. never done it before, whats involved ... as i understand it will use a 4 disk array?

Thanks,

Rob

 

[rvnguy]

TamedTech,

If you are experiencing a slow down that is traffic induced with only 15 users.....You might want to evaluate current and project future traffic

I do not know what your traffic load is, and only expounded that if it high enough w/15 users to cause a slow down that you should/could evaluate what your traffic is. There are many applications available to accomplish this.

MP3 formats are relatively compact and knowing this I am surprised that you are having a slowdown. These files can/do run in the background on many desktops while the user does other things and are not intensive in resource consumption. I would venture that you have another load source or some other problem.

I would nail this down before investing in new hardware and finding out later that the problem still exists and could have been corrected with only ?????? some little thing. A 2.4GHz unit is not a slouch for a small net environ. Many orgs are still running less than 1GHz "slot 1" proessors in their servers.

Look at your network switching

also using a stack of switches

For 15 users I don't visualize "a stack of switches". Try to determine the type that you have. If they are "Hubs" this could be a bottle neck when there are mulitple/constant net requests. A higher performance/economical solution is a "switch" and one that is un-managed is fine for a small org.

As far as setup I initially thought you would be getting this configured and setup by a VAR. If you are not experienced at configuring in the server environment I would proceed carefully. Especially if you are under scrutiny and do not have full support from the organization. It is not that you cannot do this, but it can be difficult as it is not the same as a single desktop box.

According to Microsoft, the server OS cannot be installed on a RAID 5 Array, so you would have to provide another sys for the OS and RAID 5 for the files.

RAID Definition

http://www.webopedia.com/TERM/R/RAID.html

rvnguy
"I know everything..I just can't remember it all

 

[technome]

DELL desktop PC, P4 2.4GHz, 256Mb RAM, 80Gb IDE HDD"
With 256 ram and an IDE, these is a major bottlenecks.
The new setup is good

For the fastest raid 5, 5 disks would be better than 4, though 4 is not bad. For safety I would add one more disk as a hot spare drive. Do not get cheap on the raid card, the newest generation cards have high co-processor speeds needed for raid 5, make sure you get a card with a battery backup on it. Writeback should be enabled.

For the fastest raid...
Raid 10, which would require double the number of disks would created the fastest redundant array..if you have the resources this is the way to go, but if so I would definitely have a hotspare for the array. It would be faster as there is no parity overhead involved.

If your wiring has never been cat5 certified, I would definitely have them tested. One flaky wire can slow a network down. Telephone installers generally have the test equipment.

Get a UPS !!!!!

........................................
Chernobyl disaster..a must see pictorial

http://www.kiddofspeed.com/default.htm

 

[TamedTech]

Thanks for that RVN guy ... I am resonably experienced in the configuration and administration of a domain enviromne t but being focused on the small office org networking i havnt ventured into the world of RAID yet.

As for the current setup .. i havnt run any apps to accertain the network traffic but the system presents alot of slowdown when i know that traffice is high .. i.e people are shifting around large amounts of data from the server to thier desktop and such.

As for the "stack of switches" .. That came out differently to how its was meant ... they currently have no structured cabling in place .. so the cable attached to server is into one switch ... this is then connnected to a servies of cables that run to different rooms and in each room there is another switch .. each connecting to the machines in that room.

I appreciate that the MP3 files arnt very large .. but they are being read from the network server 24/7 by the two broadbast systems ... the traffic lights on the network card seem to be constantly on.

After discussions with the users on the network they describe that when transfering large files they notice a slow transmittion speed and then the server itself becomes sluggish, somtimes that loose connection to the server alltogether and they usualy re-boot the system.

I have a UPS and Back-up systems lined up for this install aswell, we are also having the place fitted with some profesional structured cabling.

Thanks Rob

 

[rvnguy]

TamedTech,

Sorry for the conservative comments about experience. It is just that while these things are Plug&Play, they also are not. Installation/enabling order is very important and poorly documented. IRQ sharing works up to a point and then one must know how to work around it.

RAID 5: As stated, MS cannot be installed (W2K3) to a RAID 5 Array. This means you will need another sys for the OS. I have and recommend, RAID 1 for the OS & application and RAID 5 for the files. You need a minium of 5 drives for this. The RAID 1 can be of the smaller SCSI capacity. The RAID 5 can be up to what your budget will allow. You might also want to investigate the newer Serial Attached SCSI(SAS) devices available.

Double check all you concentration points to insure that you are using "switches" and not "hubs". Hubs are party-line devices and can only process a single request at any one time. As you stated, they were procured at "Staples" they might be low end "hubs" & maybe 10Mb rated.

Invest in outfitting the whole network with Gb network devices. Nic's, switches and cabling. If your clients/server/switches(hubs) are 10Mb or 100Mb going to 1Gb will provide a substantial increase in throughput.

When you have the cabling installed, specify CAT-6 and not CAT-5. See IEEE.org for details.

I just have never experienced taxing a server when employed as a "fileserver" only. Server horse power is required for server side applications such as SQL or ORCALE where the actual processing occurs on the server CPU.

Unless, there are files other than MP3, (large media type) or other large format files I really think that your bottle neck lies somewhere else. Being a traffic director (fileserver) does not normally tax the server CPU greatly.


rvnguy
"I know everything..I just can't remember it all

 

[TamedTech]

Thanks for the input rvnguy ... its much appreciated.

I am on-site with the client next week so i will do a little more investigation into the current network strains .. the concept of the project is to based on a prioritised modular install ... starting with new structured cabling and switching ... the server was the last on the list but just wanted a thorough understanding of it before we began commiting.

Due to the critical 24/7 uptime of the network i will have the new system running in parralel to the old one for a period of time before we switch 100% of the rescources onto the new system, this means we can iron out any issues we come accross.

I see what you mean about the unsual high level of strain on the file server... i havnt seen it before myself ... but by trial and error think i have checked most causes ... the server OS itself apears to run slowly, so i would have thought this means its not a network issues (cabling and switching) ... but we have done a complete system re-build on the server and the issue is still present so this would indicate that its not a software issue on the server ... error logs apear pretty clear other than a couple of errors pointing towards cacheing on disk0 .. i don't have them to hand but i will dig them out and post them in the morning.

We are not looking to begin any form of rollout untill end of september or early october so have time to re-search plenty.

Dont worry about the "conservative comments on experience" i'm only 22 and only 4 years of domain infrastructure experiece so still have plenty to learn.

I Cant stress how much of a help you guys have been. Hopefully with a little more brain storming we can come to a solution.

Thanks,

Rob

 

[NickFerrar]

Make sure your server is set to full duplex (not auto) and your switch is recognising this (hopefully it displays if the connections if full duplex..).

Apart from that I'd go with Technome's advice, Raid-10 if you want the best performance or Raid-5 if you're on a tight budget

 

[jblewis]

I've noticed a couple of comments along the lines of "Windows can not be installed on a RAID 5". That statement is only true in teh case of a SOFTWARE RAID5. With an ML-series server, or a Dell PowerEdge with the RAID hardware controllers (SmartArrays and PERCs, respectively) Windows is not aware of what the hardware underlying the "drives" is.

For best performance I would not recommend installing the OS on a RAID5, but it can be done in that circumstance. My rule of thumb is to use a pair of drives in a RAID1 configuration for the OS (and paging), and a RAID5 for the data. Technome is right, RAID5 performance shows peak nodes at 5 drives and again at 7 physical disks. There are more "optimal" spindle numbers, but it doesn't sound like you are going to have that many anyway.

I have hands on experience with both the Dell Systems, and HP/Compaq. Assuming you buying this machine new, use the startup tools it comes with! Both the HP SmartStart and Dell Server Assistant tools can walk you through setting up RAID sets very easily.

Having read the thread it sounds like the server serves up the MP3 files as files for another device on the network to play into the transmitter. Most servers today are coming with gigabit capable NICs, why not take advantage of that with a switch that has even just a single gigabit port. RVN has mentioned this too, I note.

If I had to guess why the current machine is so slow, I would start with the 256 MB RAM. Windows (2000 or 2003) is going to have to do a fair amount of paging with that amount of memory even just for basic operations. With a single disk in there, IO ops are going to get terribly queued up and if they aren't processed in a resonable amount time do get dropped.

Do some basic performance monitoring (google "key performance monitor counters" for some great suggestions) to determine where it's bottlenecked right now. That's what's going to give you the confidence to say that your solution will make an improvement, and further, you'll be able to prove it with your solution by logging those same counters and comparing them.

Just throwing out some ideas for you.

 

[TamedTech]

Hello Chapps,

Thansk again for all your help ... as current plan goes i will installm some monitoring software onto the server and see how things are running, i know there are a few on the market, anyone you would reccomend?

As we are working to a budget i think RAID5 is our current option, 5 disk array, and a seperate single of twin disk aray for the OS to sit on.

I will be using one of the HP Raid cards so i imagine as stated by Jblewis this should be easier to setup and yield a couple of benefits.

Now .. the only thing that concerns me is the cost of the disks i am currently using .. i am using SCSI 15,000rpm disks ... Technome pointed out that unless i am running SQL then this will not gain much performance over the 10,000rpm SCSI which is considerably cheaper when buying a few of them... can anyone else confirm this?

Thanks again guys,

Rob

 

[mrdenny]

Yep, get the 10k disks. You won't see a difference.

Denny
MCSA (2003) / MCDBA (SQL 2000)

--Anything is possible. All it takes is a little research. (Me)

http://www.mrdenny.com

(Not quite so old any more.)

 

[1DMF]

It is worth noting that the PCI-X slots for these cards in the HP servers are only 66mhz or 100mhz so I would concider a different box to fully get the usage out of your SCSI, an adaptec SCSI U320 dual channel raid controller runs @ 64bit 133mhz! so check before you buy!

"In complete darkness we are all the same, only our knowledge and wisdom separates us, don't let your eyes deceive you.

 

[mrdenny]

Call HP when you do your ordering. They will make sure that you get the correct cards for the correct slots.

Denny
MCSA (2003) / MCDBA (SQL 2000)

--Anything is possible. All it takes is a little research. (Me)

http://www.mrdenny.com

(Not quite so old any more.)