You won't get much/any performance increase striping the RAIDs in Linux. The amount of data that the RAID5 will need, especially with 2, 8 drive arrays will absolutely swamp your PCI bus already. If you are doing gigabit transfers on top of this your PCI bus will be hit even harder.
With 8MB files you probably want a larger stripe size for performance reasons but the 3ware cards don't have much of a selection in that area (we use a 7500-8 at work for a 1.4TB array of 200GB Western Digitals). I'm not too familiar with the ins and outs of filesystem performance in Linux but I'd choose a journaling one just for the extra reliability. Neither Samba nor NFS add too much overhead to file transfers imho so either should work for your case. However if you have a Win2k client I'd just run Samba since the Windows box needs extra software to do NFS. If the IRIX box doesn't have samba then it may be easiest to run both on the server. 3ware recommends sticking the card into a 64bit PCI slot for best performance. We're using it in a 32bit slot on a standard Intel 845G P4 motherboard and haven't had any major performance issues though the data is not heavily used (mostly a huge live backup server). If that Aopen board has 64 bit PCI slots, definitely use them. If it doesn't, with 2 large RAID arrays in one machine, you should consider the extra expense of a new motherboard with 64 bit PCI, processor, and RAM. What case are you planning on putting this in? You can find some 3-4U rackmout cases with 16 hot swappable IDE drive bays but they aren't cheap. If you have a lower budget maybe you are planning on building one? You will need some beefy power supplies for 16+ drives. Finally, this isn't necessarily important for you, but many of the new Intel 865PE and 875P based P4 motherboards have onboard gigabit LAN that uses a new bus to offload all LAN traffic from the overburdened PCI bus. In your case, this would likely give you a good performance boost. So ideally I'd grab an 865PE or 875P motherboard with the CSA Lan and 64bit PCI slots (if it exists). Er though I haven't checked to see if the kernel supports these LAN cards. Please email me privately if you have any questions. Good luck! It sounds like a fun project. :) Patrick -----Original Message----- From: Karl Huysmans [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 25, 2003 10:09 AM To: [EMAIL PROTECTED] Subject: [gentoo-user] 3 TB ATA RAID server Hi all, I am planning to build a file server running Gentoo, and before I start buying equipment, I would like to ask if anyone had any experience with a similar setup. Here's the challenge: I need to provide around 3 TB of disk space with a limited budget. The files I need to store are all HD video frames, typically in SGI format, file size around 8 MB each. The files will be accesed from an SGI IRIX workstations and from one Win2K box. All these have Gigabit ethernet interfaces. Some questions. -I really don' t have the budget to do this with SCSI disks, so I planned to use two 3ware 7500-8 ATA cards and WD 250 GB drives. I would configure the 3wares for RAID-5, this would give me approximately 3.4 TB with 16 drives. I would then like to stripe the two RAID's with Linux software RAID0, hoping this could crank up the perfomance a little bit. Has anyone ever done this ? What would be the best chunk size for the software stripe, knowing that all files will be approximately 8 MB in size? -Which file system would give the best results for this setup (ext3, reiser,xfs ...) ? Is there any way to tweak these files systems for optimal perfomance (8MB files) ? -Any tips to boost network performance ? Any tips for Samba and nfs ? Or is there another network protocol I could try ? -I have an AOpen dual PIII board available with two PIII-800 processors. Would this be enough, or could I have better performances using a newer board (dual Athlon, Xeon, ...) ? -How important is memory (speed, size) for this application? How much should I use ? Any help or ideas greatly appreciated ! -- Karl Huysmans <[EMAIL PROTECTED]> -- [EMAIL PROTECTED] mailing list -- [EMAIL PROTECTED] mailing list
