to mirror or not to mirror... that's my question 2

[Rinnt]

Hello,

Our organization of 40+ users attatched to our Citrix server is considering a serious server upgrade (currently runninng a quad 200MHz). I have always been under the impression that RAID 5 was the best disk redundancy system, and that we should utilize it in our new Citrix Terminal server. However, after recently speaking with a vender, I was informed that we should go with disk mirroring because a Citrix server is a application server (?). So my primary question is this:

When purchasing a new Citrix Terminal server (which may run Linux or Windows 200), is it better to go with disk mirroring or RAID 5?

Also, for specs, do you think 1.5-2.0 GB of RAM, a dual 1.0 GHz processor, 30 GB of drive space and two 100 MBps cards is good enough? The server will be providing all the major services except email. We will keep the old one as a backup, but we don't intend to make that a critical component of the network. Basic server functions provide MS Office, databases, print, file and custom apps. Thanks in advace!

 

[Highland]

A nitemare question...!!! We have all our Citrix Servers set-up with Raid 5 and (so far..!!) it has been reliable, we have only had a couple of disk failures and the Raid has been utilised succesfully with no server down-time....

Its important to realise that "Raid" can be implemented using either the OS or a hardware device (RAID Controller), this can make a big difference when trying to recover a system/data....and also for system performance...

Here's a link explaining the different levels of RAID...

http://content.techweb.com/encyclopedia/defineterm?term=raid

It might also be worth considering having your Citrix server for actually running your applications and a second server which acts as file/data storage....

 

[jimbopalmer]

RAID 5 is very cost effecient, but is not the 'best' in terms of perfomance or reliability.

mirrored stripes, RAID 1 + 0 or RAID 10, all buzzwords for the same layout, offeres the fastest reads, faster writes than RAID 5 and considerably better redundancy. The major drawback to it is that you consume 50% of the disk space in duplicated data.


I tried to remain child-like, all I acheived was childish.

 

[Rinnt]

So that sounds like:

2 votes for Mirror (1 from our vendor)

1 vote for RAID 5


...any one else have any input???

Note that because we might be utilizing Linux, we wouldn't be able to do seperate file/print/application servers... Thanks for the votes guys!

 

[epohl]

I typically use a setup that uses a Raid 1 (mirror) for the drive that holds the OS and then setup raid 5 for the data.

 

[jimbopalmer]

I do not feel I was voting, just correcting an impression that RAID 5 was 'best'.

Use RAID 5 to get larger, more reliable drives from smaller cheap drives.

Use RAID 1 + 0 to get the most relable, fastest drive subsystems where size is not an issue. I tried to remain child-like, all I acheived was childish.

 

[behind]

I vote for Raid 1+0. TS should be only a application server
no data´s on the TS-Server. Most of our costomers (bank,f insurance company) use Raid 1+0.

 

[wilsona]

Cheapskates - Disk is not expensive. Some people do keep data on citrix servers. Hardware RAID 5 is much, much better than simple mirroring. I rest my case, gentlemen.

 

[Rinnt]

OK so I guess I should've just asked which is better:

Ford or Chevy




wilsona, other then the fact that you don't think disks are expensive, could you support your argument that RAID 5 is "much, much better"? Especially since the votes seem to favor mirroring.... I need to consider two senarios: 1) EVERYTHING (files and apps) might be stored on the server and 2) I might have another server to throw apps or files on so the new one could run either apps or files...

 

[MISAdmin]

Rinnt,

I personnaly decided to use RAID 1 on our Citrix server since we only load applications there and store no data files on it whatsoever. We have a seperate server that houses our data and it has RAID 5.

Your server specs sound good. You did mention that you might be running on Windows 2000, but you didn't specify whether you were running XP or MF 1.8. If you will be running XP, I wouldn't even think about going back to a quad processor box... Depending on which version of CitrixXP you buy... you can get it with load balancing built in... so, you can install the software on as many machines as you want and just load balance them. Thus, for upgrading, it's cheaper to buy a dual processor system now and throw another dual processor system on the network later for expansion than to buy a very expensive quad processor system now with the idea of being able to expand with it in the future...

Just my $.02

 

[Highland]

To be honest, I don't think it really matters which version of Raid you choose.....!!!....what DOES matter is how it performs when you have any problems with your disks....!!! I think you should consider how you implement the RAID system you choose, whether you choose software or hardware as the "controller" for the installation is more important (I think) rather than if you use RAID 1, 5, 10 or whatever....!!! Basically, (as everyone has pointed out) all these configurations will work and will provide protection for your data/disks...its how well your implemetation works when you most need it that is most important...????

 

[MISAdmin]

I totally agree with Highland. And, personally, I wouldn't implement software level RAID with anything...

 

[wilsona]

Mirroring is just not as secure as RAID 5. There are plenty of publications on the subject which I suggest you read. Try

http://www.acnc.com/raid.html

If security of data and minimum downtime are important, then RAID 5 and hot spare is the way to go. Speed need only be a consideration for specialised systems performing real time transaction processing. The only reason you should use mirroring is for 1U high application only servers to which you physically cannot attach enough disks. You data in this case will probably be on NAS boxes which should use RAID 5. Even on application servers, if you can get enough disks in, you should use RAID 5.

Here is what I suggest - you buy a hardware RAID controller and 4 disks. Three are for RAID 5 giving you just under 2 disks worth of free space. The additional disk is for a hot spare. Bulletproof. Unless it goes on fire...

If you can't afford the disks, you certainly can't afford to use Citrix - Subscription Advantage per annum alone costs the same as two 10000 rpm scsi drives. You always buy hardware maintenance too, don't you? Computing should NEVER be done on a shoestring, it's not worth the hassle.

 

[Rinnt]

Thank you all for your input. Unfortunately working for a municipality in this case means shoestring computing. I just wish you could make our town council understand the consequences of this shoestring computing... That's why I'm researching a Linux Migration (pretty extream, eh?). However, Microsoft and Citrix will likely always be part of the infrastructure.

Truthfully I have had no training in Citrix, and was literally left to figure everything out. Will 1.8 Metaframe still run on Windows 2000 or will we need to upgrade that as well? As it is, a Microsoft and server upgrade is going to be pricey! And how is that we could run XP from the terminal server when there is no XP server product yet? Also, the CitrixXP is a new term as well... Is that the solution?

 

[DevilDog]

OK... looks like I need to put in my $.02 into the pot. In my environments I have used two types of configurations; #1..All on RAID-5 with HOT spare at the hardware level. #2..The OS mirrored and the application/data on RAID-5 (always hardware RAID).

Whether you go with #1 or #2 would depend on where you will keep your databases. Use #2 if you keep them local on TS server. Remember Citrix Load Balancing. If you do use this (I would rather run 2 smaller servers load balanced than 1 big one) than you will have no choice but to place your databases on a back-end server for common access from the Citrix farm. However, if you use only a single Citrix server than I would go with #2 and place the databse local to improve response. No need to push data across network.

You have many options here. Good Luck.


-- Devil Dog --