RocketRaid 2340 Raid 5 Array

[Alexander_Q]

I'm sticking a RR2340 on my Asus a8n32 Sli mobo and building an array of 5 WD Corsair 500gb HDDs. I intend to expand this array by adding a 500gb every 3 months or so using OCE.

Is there a limit to the size of the array that I can create, impose by either OS or some other factor that I am not aware of?

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Hi folks. Nice forums you have here - answered a few of the questions I googled just by looking at old threads. Kudos.

 

[axan]

there is no limit for the array but the biggest single volume you can have is 2tb unless you use gpt partition system ( http://en.wikipedia.org/wiki/GUID_Partition_Table )

 

[Alexander_Q]

Is this an operating system-imposed limit? The description of the controller says "64bit LBA for over 2TB support". What does this mean?

 

[drizzt81]

Is this an operating system-imposed limit?

yes, this is a windows OS limit for the maximum size of a single partition.

The description of the controller says "64bit LBA for over 2TB support". What does this mean?

This means that you can create a single array with a total size of more than 2TiB. If the controller did not feature this, your maximum size for a single array would be 2TiB.

 

[axan]

the high point controller supports volumes over 2tb (i have 3.5tb volume on my hp 2320) but like I said you have to use guid partition tables.

 

[Alexander_Q]

Cheers guys.

"Can the 32-bit version of Windows XP read, write, and boot from GUID Partition Table disks?
No. The 32-bit version will see only the Protective MBR. The EE partition will not be mounted or otherwise exposed to program software."

Does this mean that if I use the RAID as a fileserver, network computers running Windows XP 32-bit will not be able to see/access/make use of anny of the files?

 

[axan]

no you will be able to access it from windows xp machines just fine, for example my file server runs freenas ( freebsd distro) i have 3.5tb volume on hpt 2320 card and i can access it over network from windows xp without problems. The only thing is you can't have gpt volumes on 32bit windows xp (as in the drives being physically connected to the system running 32 bit xp), only xp 64bit and 32+64bit versions of server 2003 support gpt partitions and only as data drives ( can't boot from them).
If you building a dedicated file server i would suggest going with either freenas or some linux distro they are more efficient but if you're not comfortable with *nix oses then it can be done on 64 bit version of xp or any version of server 2003+

 

[Alexander_Q]

Cheers Axan, that's good news. I've obtained a x64 version of windows for this purpose - I'm not opposed to using Linux, I just have had zero experience with it. All of the computers accessing the server would likely be running Windows 32-bit - are they able to easily interface with a computer running Linux?

I guess all that remains is learning to handle the GUID partition table. I've only got the wikipaedia page and the microsoft support page for reference; the latter mentions that the maximum NTFS volume size supported on a GPT disk is dependent on the "cluster size", with the biggest cluster size 65,536 allowing for a 256TB volume.

Is cluster size something I can determine at time of formatting without restriction? For example, are particular hard drives limited in the size of the clusters they can contain, and is there some detrimental side-effect to formatting with the largest cluster size?

Here is the extract from the support page that concerns me: "Maximum NTFS volume size supported on a GPT disk - This depends on the cluster size that is selected at the time of formatting. NTFS is currently limited to 2^32-1 allocation units. This yields a 256TB volume, using 64k clusters. However, this has only been tested to 16TB, or 17,592,186,040,320 bytes, using 4K cluster size."

 

[axan]

I think windows by default uses 4k cluster when formating ntfs, not sure if you can change it because i never really dealt with gpt under windows but even if it's 4k that would give u 16tb volume which i think is more then enough. Anyway before you decide to use xp 64. Jump over to http://www.freenas.org/ and check it out. It's a very good out of the box file server os, it only takes 32mb and can be installed on hard drive or usb jump drive. It has support for high point raid cards (hover if you want the cli for creating and administrating raid arrays that requires some custom work, you can get my script here ) It's very easy to administer and set things up, you do everything through web interface. If you interested in it and have any questions feel free to ask me.

 

[Alexander_Q]

Cheers, I'm gonna mess around with XP x64 and Freenas over the next week and then report back here. Thanks again Axan.

 

[Dew]

For this situation, expecially since you want to expand the size of the partition, I suggest you looking into XFS on Linux.

XFS is awesome on performance and you can run it with no partition tables whatsoever, completely bypassing the headache that is GPT(well, it was when last I messed with it, a year ago).

Here is the formatting parameters I use on my two 2.03TB arrays(small I know, but it wasn't so small almost two years ago).

mkfs.xfs -f -b size=4k -d su=64k,sw=7 -i size=2k -l version=2 /dev/sda

Just replace sda and you'll be rolling in less than a minute.
When you add drives to the array, after OCE is finished, just run xfs_growfs, 10 seconds later you will have an expanded array, after reboot. I have done this twice.

I use FC5 x64, mostly because that was the new thing when I built the second array and it had pre-compiled drivers. HPT releases precompiled drivers for Fedora, SUSE, SLES, Centos, and RHEL. They don't have pre-compiles for the newest Fedora/RHEL/Centos, but they should in another month or so.