RAID 0 basics: Optimal stripe size for best performance (for HDTV recordings)

[scat]

Originally Posted by mkanet

I'm glad that I decided to go with RAID 0; despite how others theorized and analyzed about how RAID 0 shouldn't make a difference (in what I wanted to accomplish). I have clear proof that it does. I just _knew_ I was right; at least to some degree, about the effectiveness of RAID 0, but couldn't prove it. However, thank you guys for responding anyway.

I am able to record all 10 tuners at the same time and still comfortably FF/REW without any issues. I couldnt do close to that before on the same machine, same controller, same software. The only thing I changed was where I save to... a 2 disk RAID 0. In fact, even the disks I'm using for RAID 0 is practically identical to the 1 disk non-raid recording I used to do. Both non-RAID disk and RAID 0 disks were formated with 64k cluster size. I decided to go with 128K stripe size for the RAID 0; which worked out perfectly.

This thread might be useful to those interested in RAID 0 who aren't sure of the real-world benefts for sageTV. I can't imagine why someone else using RAID 0 under similar conditions would have different results.

mkanet

Please list your original hardware then the new added Raid hardware.

Thanks
Scat

[stanger89]

Yeah, I too am curious what all changed.

[mkanet]

Sorry it took so long to respond... Nothing really special as far as I can tell; except for the new disks having double the on board cache.

My hardware never changed except for replacing one SATA HDD with two SATA HDD... both single and RAID0 disks were using NTFS 64Kb cluster formatting.

Controller: Embedded Intel ICH8 SATA
Old HDD: 1TB SATA WD 7200RPM (16MB cache)
New HDDs: 1TB SATA 7200RPM Samsung Spinpoint F1 (32MB cache) x 2

CPU: IntelQ6600 2.4GHz quadcore
RAM: 4GBs



for removing my old WD 7200RPM SATA disk and...

Adding an extra SATA cable and two new 7200RPM SATA disks (Spinpoint F1

[MrVining]

Seems to me the larger the cluster size the less often the drive or drives need to seek. Makes sense that you would see a performance increase raided or other wise.

I'm still trying to make up my mind on hardcore raid5 or not (I like to watch TV pretty much a season at a time). Personally I like the way SageTV uses multiple drives. Sure it's a bit of an issue if you ADD a drive, but once you hit 5-6 drives I would think that they would stay pretty balanced.

[mkanet]

Yeah, its cool that SageTV offers multiple locations to record to; however, the more locations you have, the more difficult it is to manage them (for me at least); which is where RAID is useful

Personally, if I had a whole season to catch up on that I recorded back in Fall/Winter/Spring, I would definitely use RAID5 intead of RAID0 not to lose any data. If I had enough money right now, I'd get a good hardware RAID controller and use RAID5.

Originally Posted by MrVining

Seems to me the larger the cluster size the less often the drive or drives need to seek. Makes sense that you would see a performance increase raided or other wise.

I'm still trying to make up my mind on hardcore raid5 or not (I like to watch TV pretty much a season at a time). Personally I like the way SageTV uses multiple drives. Sure it's a bit of an issue if you ADD a drive, but once you hit 5-6 drives I would think that they would stay pretty balanced.