FreeBSD Raid Options - Software vs. Hardware

Vibe

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Aug 3, 2005
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111
Hi everyone,

I am preparing to build a new FreeBSD/DA server and am curious about the possibility of using a software raid option. We have a couple FreeBSD/DA servers that are using 3ware raid cards (raid-1) - which work fine thus far.

In another post on the forum jlasman (thanks for the info!) mentioned software raid on Linux being an excellent option (performance + cost savings) - This Post.

With this in mind I setup an Ubuntu test server with software raid and I am VERY impressed with the performance (This has since become my home backup server for DA client backups).

With regard to FreeBSD - I have setup several Samba file servers using GMIRROR and while the systems were very stable - disk performance was pretty poor (e.g. cannot hold a candle to Linux software raid). Until I setup the Ubuntu server above, I had preconceived notions regarding performance based on GMIRROR - STABLE and SLOW.

Low and behold - I again revisit the notion of software raid with FreeBSD. Has anyone implemented a software raid solution that could handle the typical load of web/database/email services under DirectAdmin?

For the DA/FreeBSD users - what is your standard Raid solution (hardware/software/none)?

Thank you for any input/suggestions you provide!
 

rfauske

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Aug 8, 2007
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We use gmirror with the load option when not using HW raid and havent had any performance issues with it.

When HW we used to use 3Ware but am changing to Adaptec 2405 or higher becouse if the better os support and so on.
 

Vibe

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Aug 3, 2005
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111
Hi rfauske - thank you for your reply and the Raid card recommendation.

I have not had much experience with Adaptec raid cards (usually have gone with 3ware) but I am growing weary of the high expense - especially for basic mirroring.

Are there any noticeable differences in performance between your GMirror'ed servers and those outfitted with the Adaptec cards? (e.g. do you use the Gmirror'ed servers for "basic" duties and the HW Raid servers for full service)

It would be great to bypass the raid cards completely - excellent cost savings. GMirror has been very stable otherwise - just not sure it will handle typical loads (e.g. we try to keep our servers at around 175-200 domains, 500-750 email accounts max and no more than 50-75 MySQL databases each. Spam/virus filtering is offloaded to a separate box).
 

rfauske

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Aug 8, 2007
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I have been using it on a server with around 500 domains (no mail/sql as I have that on another server) and I have used it on my mailserver that has around 1200 users with no issues

One of my clients run it as a full service DA with gmirror and a dual core xeon 2.13, 4 gig ram and 2x250gig sata (with gmirror) and has this stats from his server (he uses suphp):

# of Domains 217
# of SubDomains 42
POP Email Accounts 739
Email Forwarders 183
Mailing Lists 8
AutoResponders 2
# of MySQL DBs 170
Domain Pointers 116
Ftp Accounts 192

And the server is happy with a load around 0.4 (almost all sites hosted are Joombla sites)

But my experience is that if you are not going on one of the more highend controllers with battery backed cache (otherwise write cache is kind of dangerous for the DBs and filesystems) you will notice almost no difference between software and hardware based mirroring.

--
Rasmus Fauske
 

Vibe

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Aug 3, 2005
Messages
111
Thank you very much for the information Rasmus!

Your clients' server is definitely a notch above ours - we have older hardware (and not as many clients :eek:). It is very interesting to know that with the loads you mention they don't experience any issues. We may have to revisit this for an "inexpensive" raid option. Do you setup GMirror to raid the system as well as /home ?

We too have been looking at the Adaptec 2405 cards - however, I don't believe they have BBU capability like you mention. So we may have to look at something like the 3405 instead.

Thanks again for your suggestion - certainly appreciated!
 

rfauske

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Aug 8, 2007
Messages
19
The servers are mostly 2 drive setups so everything is mirrored including /home and so on.

The only issues is if the drives are rebuilding during fsck and/or high load it gets slow. But that will mostly all raids do during rebuilds ..
 
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