Hi everyone,

I am rebuilding my server and I need some advice on drive configuration. Here are my system specs:

motherboard: Tyan S2735 w/ 2x's P4 2.6
memory: 6 gig DDR 2100 ECC
HDD: 2 x 40 gig Seagate SATA hard drives
HDD: 4 x 500 gig Seagate IDE hard drives on a 3Ware 7500 RAID controller in a RAID 5 configuration
OS: CentOS 5.3

Planned use:

I want to have several virtual machines, (probably OpenVZ server, however, I have just started playing with Xen). I intend to create a virtual Samba server and mount my 4 x's 500 gig array under that. I then want to create virtual web, email, ftp servers with virtual a reverse proxy server to mange the whole thing, (web side, not Samba).

I want to setup the 2 40 gig SATA's in a RAID 1, (mirror), configuration. I have an on-board hardware raid controller on the motherboard, however I have been reading that linux softraid gives a much higher I/O than the hardware raid.

Does anyone have any advice or suggestions on which way to go for the configuration that I am trying to do? I have always been a hardware RAID fan myself, but the performance specs for softraid are really impressive.

Also, should I use the default formatting or would I be better off manually creating the partitions?

Thanks

zog

Most motherboard "hardware" raid is actually "fake raid". If you have fake raid and aren't trying to use it across a Windows/Linux dual boot, don't try to use it at all. Software raid is better.

True hardware raid may be significantly faster than software raid. It is "fake raid" that would be slower than software raid. But even so, the phrase "much higher I/O" would not be accurate. Fake raid would use all the same I/O paths as software raid, with only a little more software (not I/O) overhead and a little less configuration flexibility.

Confirm it is fake raid, then don't use it.

What do you want to use the various partitions for?

Even bothering to use 2 x 40GB drives when you also have 4 x 500GB is strange. What special purpose do you have for that storage that justifies the attention you seem to be giving it?

For example, if you want the 2x40 to hold the basic system (Installed Linux software and swap, etc.) I would suggest manually partitioning both drives identically and using software raid 1 for the partition(s) where software is installed.

But swap is best if you just enable both swap partitions (one on each drive). That gives Linux the flexibility to get raid 0 performance from swap space if the system load involves enough swapping to matter, while you don't have any of the overhead of explicitly defining any raid for the swap. The total of the two swap areas should of course be double what you think you need, so you don't need to repartition if you lose a drive. You would lose only the raid 0 like performance.

So far as I understand, software raid 0 for a swap partition has no performance advantages (and possible performance disadvantages) vs. simply having two equal swap partitions on separate physical drives. Raid1 for swap makes even less sense (maybe makes sense to achieve very secure suspend to disk. I'm not sure).

Hi johnsfine,

No, it is an actual hardware raid, (Tyan makes excellent server boards!).

As for the 4 x 500's, these are my data drives for my current Samba server. I have them on a PIII server board, (Tyan S2510), with the OS on a 10 gig drive. I prefer to just mount my existing data on the virtual Samba server and not have to worry, (too much!) about the data on the drives, (yes, yes, I know, I know, BACKUP, BACKUP, BACKUP!!!).

I am trying to reduce the number of machines in my home office, currently at 7 including my laptop, plus my girlfriends desktop and laptop, plus my sons desktop, server and laptop, (fortunately, my 4 year old daughter does not YET have a computer) as well as my reducing my electric bill. The sound of all those high db fans is another factor, currently I am switching everything I can to water cooling, if you take your time you can get everything on ebay for less than $50.00 USD per machine!

I was considering formatting in the following manner:

/boot 100 meg
/swap 8 gig
/ 5 gig
/etc 2.5 gig
/opt 2.5 gig
/var 2.5 gig
/usr 2.5 gig
/home 14 gig

I am not expecting a heavy load on this machine, it is my home/soho server with a max of 4 users at any time. I would like to create a virtual machine to act as a back-end server for myth-tv at a later date, but once again I don't see myth-tv using up a lot of system resources.

Thanks

zog

edit: just realized my mistake on the hard drive partitions. Will think/read a little more about it and then re-post.

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