BBU - on PCI card?

LeaUK · 8th December 2007

Hi all

I've recently had so many problems with the onboard Adaptec RAID controller (simply running at RAID 1) that I'm tempted to go 3WARE http://www.3ware.com/products/serial_ata2-9650.asp.

Random rebuild requirements, random verification requirements (these are 8 hours a piece), Win2K3 displaying the RAID partitions twice ie, C: and D: on the RAID array now with E: and F: which are identical copies - I guess due to some type of screw up in the array mirroring..

It's driving me nuts and is hardly the level of reliability I require. In fact I've had far better reliability from single disks!

So, after ranting about my frustrations, here's probably what seems a silly question. Those RAID cards offering BBU 'support' does this actually mean they have an onboard backup battery, or is that purchased separately. It's just that I can't physically see one on the pictures.

Cheers for any advice.
Lea

LeaUK · 8th December 2007

Here;a another stupid question.

Will the card come with the SATA/SAS interface cables for all 8 drives? And, does 3Ware have a Win interface to modify/check RAID status?

??

othellotech · 8th December 2007

Quote:

Originally Posted by LeaUK2

Those RAID cards offering BBU 'support' does this actually mean they have an onboard backup battery, or is that purchased separately

Generally if it "supports" it then its a purchasable addon

Karl · 8th December 2007

3ware - Comes with cables 99% of the time, although there is a product code for ones that don't come with cables or CDs usually, comes with tools for managing it from Windows. BBU are 99.9% of the time an optional purchase.

LeaUK · 8th December 2007

Thanks guys, that confirms my understanding of the wording 'supports' and also ties in with that fact that I can't see any Bats on the card.

I'd appreciate your comment about what could be causing my arrays to want to verify and rebuild once a week - would going 3Ware card resolve this. Is this typical behaviour of on board RAID?

Cheers
Lea

othellotech · 8th December 2007

Quote:

Originally Posted by LeaUK2

I'd appreciate your comment about what could be causing my arrays to want to verify and rebuild once a week

The list is potentially endless - bad disk, faulty card, incorrect driver, misunderstanind of raid usage, disk uage patterns, raid level vs partition split, dodgy psu or fluctuating powersupply, mangled cable, bad luck ....

Karl · 8th December 2007

You'd know if there was a BBU, they aren't usually small and discrete.

PSU and power supply would be my first call, if SMART doesn't flag anything for the drive - Usually the RAID card should flag why it's causing a rebuild though, I know we've just done a couple of drives that were reporting sector re-maps, wasn't causing a rebuild though.

othellotech · 8th December 2007

Quote:

Originally Posted by LeaUK2

Win2K3 displaying the RAID partitions twice ie, C: and D: on the RAID array now with E: and F: which are identical copies

Which beggars the question - why are you splitting the disk into multiple partitions ?

JamesSykes · 10th December 2007

Onboard raid is typically quite shite. I recently built a box with an 8port 9650. BBU was an extra £60 but very much worth it for the performance boost you get enabling write caching.

LeaUK · 11th December 2007

Thanks for the comment guys. I have write caching enabled which perhaps is causing the issues. I always power down gracefully (bar one reboot a while back) such the cache is flushed. Am I correct in understanding that once the server has been powered down (from a W2K3 shut down), fans stopped and ready for boot, the cache has been flushed? i.e. now safe to pull IEC inlet?

The disk is split to allow simple manageable imaging. Actually there are three partitions. c: for OS, D for images, drivers, install software etc and the third (large) to be served via iSCSI.

The system would perhaps benefit from another set of spindles managing the iSCSI partition, but that's another 3 disks, and the performance is fine for now. When expansion or throughput become an issue I'll just pop them it and reconfig my iSCSI

Lea

JamesSykes · 11th December 2007

I wouldnt write cache unless i had a BBU because that is just asking for trouble

It's worth picking up a 3ware and bbu. The 9650's are very well priced if you only need a few ports.

LeaUK · 12th December 2007

re write caching, strange it's enabled by default then? You're 'write' (sorry couldn't resist) I'll disable the cache and see how I get on.

Cheers
Lea

Karl · 12th December 2007

Enabled by default, to make them look good in the performance stakes