new server - 8 drives, hardware RAID, how to configure?

[Kremlar]

Putting together a new server for my home/office, and trying to decide how to configure the drives.

Server will be an Active Directory server for a small LAN (5-8 users), but primarily a data / media server for streaming DVDs, photos, music, etc.

Using an LSI Logic RAID controller with (8) Seagate SATA 1TB drives. Most of the servers I configure are lower capacity with 6 SAS drives. I typically configure 2 drives in a RAID1 configuration (system/OS array), 3 drives in a RAID5 configuration (data array), and leave the 6th drive as a global hotspare. I go with 2 RAID arrays instead of 1 big array with 2 partitions figuring there is a performance benefit (simulaneous access on 2 different RAID arrays should be quicker than simultaneous access on 2 partitions on the same array, right?).

With this server, I'm considering using RAID6 since I have 8 drives to play with and because of the capacity of the drives - even with a global hotspare, it might take a day or 2 to rebuild the RAID5 in the event of a drive failure. If a 2nd drive failed during that time, I lose my data. With RAID6 I'll have 2 parity drives to play with.

So, I'm looking for opinions. Here are the options I'm considering:

(1) - 2 drives RAID1, 6 drives RAID6, no hotspare
(2) - 2 drives RAID1, 5 drives RAID6, 1 drive global hotspare
(3) - 7 drives RAID6, 1 drive global hotspare

Opinions?

 

[pjkenned]

For my WHS box, I ended up doing 8x 1.5TB drives in Raid 6 (of the 11 I have on-hand) and 2x 1TB drives in Raid 1 (OS Disk) on an Adaptec 31605 (yes using the IOP333 @ 800MHz).

What will this box be used for? Is it going to be a primary data store or a backup server?

If you are low on ports, I would go for (3) assuming it is a primary data store.

On the other hand, if you are making a backup of other PC's, Raid 6 is basically providing 3 drive loss redundancy because you have the main PC (assuming no raid 1/5), then 2 drives on the Raid 6 server array.

I'm using a 8x 15k Savvio "OS" storage raid 5 array on the main PC and 3x Cheetah 15k.5 300GB's as secondary storage, with 3x 1.5TB drives in raid 5 providing local backups and temporary space for HD footage. Then my first two levels of drives are backed up to the Raid 6 WHS which basically means that to lose data I need to have 5 drives fail in the chain. Another upside is that staying away from Raid 1 for the majority of the storage has allowed me to keep maximum capacity and really nice speed.

On the other hand, there are "some" files that I've deemed non-critical that exist only on the Raid 6 array on the WHS box, but that is still allowing 2 drive failure.

As a point of reference I tried rebuilding an 8x 1.5TB array on the Perc 5/i w/ 512MB of ram flashed to the equivalent LSI bios and the 500MHz IOP333 was dyind rebuilding the array over more than 50 hours.

With this in mind, and I'm sure you have it covered, make sure that any huge array you build has both a BBU for the Raid controller (no-brainer) and a battery for the system.

 

[Kremlar]

Thanks for the detailed reply!

Yes, this is primarily for live data - not backups. Only a small percentage of the data stored on here is critical to me (documents, photos, music, smaller videos), and that data will be backed up nightly to a different box and also archived periodically to DVD for storage in a fireproof safe. The rest of the data (ripped DVDs for wholehouse playback, recorded video, etc.) is not critical and I'm not concerned about backing that up. To be honest, this is way more capacity than I need (for now anyway), but for the price it's a no-brainer to go with at least 1TB drives.

To provide a bit more detail, the RAID card I'm using is a LSI 8708ELP. I will be using a battery module for the RAID card (won't be in for a couple days), and I do have a decent UPS for my server rack.

Here's a thought... I'm using an Intel S3210SHLC motherboard for this server. What if I installed a couple lower-capacity SATA drives (say 320GB) on the motherboard's SATA RAID controller in a RAID1 configuration? That would protect my system/OS partition, and leave me all 8 drives on my LSI RAID controller for a 6TB RAID6 partition.

Thoughts?

 

[brxndxn]

8 drives.. raid 0.. live fast.. live dangerously..

 

[pjkenned]

That's exactly what I would and do generally do. That way you have OS tied to the box and storage tied to the controller if you ever want to move anything around.

 

[Kremlar]

That's exactly what I would and do generally do. That way you have OS tied to the box and storage tied to the controller if you ever want to move anything around.

Thanks, that's what I'm going to run with...