Need Raid 5 Suggestions / Help

[mdmint]

Originally Posted by salsbst

Is there any drawback to the 2810SA (other than price)? It seems a lot of people were recommending 3ware, and yet in my research I can't find any reason to choose anything other than the Adaptec 2810SA (if you're not sitting on a whole bunch of PATA drives).

No drawbacks I know of other than price of course, feature advantages yes! OCE, RAID level migration, optimzed disk utilization (ability to use full capacity of different sized drives in array) features NOT support by Escalades. I'm fairly satisfied with the Escalade 9500S-8 since I built fully HD populated so OCE and/or migration wasn't an issue. Cost was indeed my only reason for going 3ware vs Adaptec.

Is the 2810SA compatible with the SATA backplane for the Chenbro RM312 case?

Don't know but would hope so, you'd really want to check with Adaptec support.

BTW, since the RM312 supports 12 HDs, why the 2810SA that only supports 8 HDs? How 'bout the 21610SA that supports up to 16 or 3ware Escalade 9500S-12.

[edgley]

Have a look at www.open-e.com, looks good.

Its NAS on a moduel that plugs into your IDE port, so you need no OS for raid

[salsbst]

Originally Posted by mdmint

No drawbacks I know of other than price of course, feature advantages yes! OCE, RAID level migration, optimzed disk utilization (ability to use full capacity of different sized drives in array) features NOT support by Escalades. I'm fairly satisfied with the Escalade 9500S-8 since I built fully HD populated so OCE and/or migration wasn't an issue. Cost was indeed my only reason for going 3ware vs Adaptec.

Don't know but would hope so, you'd really want to check with Adaptec support.

Thanks, mdmint!

BTW, since the RM312 supports 12 HDs, why the 2810SA that only supports 8 HDs? How 'bout the 21610SA that supports up to 16 or 3ware Escalade 9500S-12.

I was thinking that I'd RAID1 (mirror) the OS volume using the motherboard's RAID 1 feature and RAID5 the data volume using the 2810SA, hence the 8-way card and the 12-bay case.

I may just get the 4U 16-bay case, though. I'm sure I'll want that much room eventually.... especially when we move from an apartment to a house, at which point I'll be able to stuff the thing in a closet. For now, I have to listen to the thing in the bedroom that we use as a study, so I'm trying not to put too many drives in for fear of drive noise and the needed fans drowning out the brainwaves.

[salsbst]

Originally Posted by edgley

Have a look at www.open-e.com, looks good.

Its NAS on a moduel that plugs into your IDE port, so you need no OS for raid

Thanks, edgley, but I can't figure out what this thing does. As far as I can tell, it allows me to avoid using Windows or Linux to run the server -- it is its own OS. Is that correct?

[mdmint]

Originally Posted by salsbst

I was thinking that I'd RAID1 (mirror) the OS volume using the motherboard's RAID 1 feature and RAID5 the data volume using the 2810SA, hence the 8-way card and the 12-bay case.

Make sure your BIOS will allow you to boot off the onboard RAID1 when using PCI slotted RAID Ctrl. Some BIOS merely allow selecting SCSI as boot selection, not giving specific choice of which, so first SCSI to ini is the boot ctrl. (these SATA & PATA RAID controllers seen as SCSI) I know for a fact the ASUS A7N8X-E Deluxe mobo will not boot off the onboard SATA with slotted RAID controller, ini priority goes to the slotted. Talked to ASUS support, no way around it, weakness of their BIOS implementation. Can still use RAID1 & RAID5 and boot off RAID1 if both arrays on same controller of course.

[salsbst]

"Comparison of nine Serial ATA RAID 5 adapters": http://www.tweakers.net/reviews/557

edit: somehow it appears that the Adaptec did not make the list of nine!

[mdmint]

Originally Posted by salsbst

"Comparison of nine Serial ATA RAID 5 adapters": http://www.tweakers.net/reviews/557

edit: somehow it appears that the Adaptec did not make the list of nine!

While my Sage Server's 3ware Escalade 9500S-8 & my workstation's Promise FastTrakS150 SX4 are serving me fine I'd most definitely look extremely hard at an Areca if I was building now. Besides the Areca's performance test results, I would love to have it's RAID6 support on my Sage Server! Currently using RAID5 with online spare. (which means only 1 drive can fail without loosing data of course though at least with online spare rebuild begins immediately) RAID6 would yield same storage capacity I now have but with better redundancy enabling 2 HDs to fail without loosing all date before rebuild.

[salsbst]

Thanks alot for the BIOS tip, mdmint. That will be a factor to consider when motherboard shopping. I like ASUS, so maybe I'll just put the OS array on the RAID card as well. I'm still a little unclear, though, about the reasons for avoiding putting the OS on the same array as the data...

I noticed a negative comment about the Adaptec on slashdot today... I'm going to check out the Areca.

[mdmint]

Originally Posted by salsbst

Thanks alot for the BIOS tip, mdmint. That will be a factor to consider when motherboard shopping. I like ASUS, so maybe I'll just put the OS array on the RAID card as well. I'm still a little unclear, though, about the reasons for avoiding putting the OS on the same array as the data...

It's normally for performance reasons AND in Server environments. Common to use the smallest possible HDs (and = cheapest possible) for RAID1 OS and larger HDs (= more expensive) RAID5 for storage.

That said, do to my design changes after discovering how simple Sage is to use and chews up storage, plus mobo not supporting onboard SATA RAID1 boot, I've been running my OS off same 7xHD RAID5 array as main Vid storage no problem since May04. (small OS partition with small clusters rest single large 64k cluster partition) I'd originally planned a 750MB video array off Promise FastTrak S150 SX4 with 4x250GB and 2 smaller SATA RAID1 off mobo, couldn't do it. (ASUS BIOS got me) 750MB video storage too small anyway, so re-deployed the Promise in my main workstation using 500MB of it for Sage Library and went the 1.5TB Escalade array.

Config'd 5GB OS, 1.495TB video, turns out 5GB OS too small! Took some tricks have enough space to be able to go from WinXP Pro sp1 to sp2. 10GB OS partition would have been better but I'm not going to mess with something like Partition Magic and don't have a way to backup the current 800+ GB Sage recordings on the main video partition so it stays the way it is for now...

[salsbst]

Performance reasons makes sense from the drive caching/spinning/seeking standpoint.

Is Norton Ghost able to access partitions in the typical hardware-based RAID array? My only experience with RAID is software RAID under linux. I'd like to be able to Ghost the system volume to an image.

[mdmint]

Originally Posted by salsbst

Is Norton Ghost able to access partitions in the typical hardware-based RAID array? My only experience with RAID is software RAID under linux. I'd like to be able to Ghost the system volume to an image.

Yup, hardware based RAID presents logical partitions that look like any other logical partition. I Ghost my OS partition residing on RAID5 to a single PATA HD I have stuffed/wedged/shoehorned in the Server somewhere. (It's actually in the space you'd normally put a FDD, didn't put one in my Sage Server)

Actually just re-Ghosted this morning before upgrading Sage Server from 2.1.10 to 2.2 release (2.2.7). I don't Ghost it as an image, actual partition to partition Ghost. That way can boot off the PATA if I want/need to. Though probably wouldn't do much good since if OS partition down highly likely Video partition on same array down too!

[mikesm]

Originally Posted by salsbst

Thanks, edgley, but I can't figure out what this thing does. As far as I can tell, it allows me to avoid using Windows or Linux to run the server -- it is its own OS. Is that correct?

Well, not quite. Open-E NAS product is based on linux, but preconfigured for NAS operation with a webserver frontend for control. It can use software RAID and I would assume give you the same excellent performance that Linux software RAID would give you, but avoids you having to learn linux to build and manage one. Or at least that's the theory.

BTW, check out this blog entry for how someone in Switzerland build a 2 TB RAID5 NAS server and the performance he's seeing: main article. There is a great thread on this project here at StorageReview.

And here is a link to a more "Ghetto" but low cost NAS implementation: "Ghetto" NAS. I don't like the way this guy mounted his disks from a cooling point of view, but it's still an interesting implementation. I won't repeat previous comments about how cooling is ESSENTIAL to disk drive life. :-)

Thanks,
Mike

[infiniti_guy]

I was wondering if any of you have had success with the following features/configurations for your RAID Sage servers:

1) Cool'n'Quiet - Theoretically not supposed to make a difference, but I am not so sure for this application. I tried it and saw video playback errors on my clients, but I wonder if anyone else had success...

2) ECC RAM - I was thinking that the ECC would help under the situation of multiple large file transfers, but it may have an effect on Client video performance. I still have a little bit of occasional choppiness of video (not always, but after time), and I was wondering if the ECC casues some type of memory backup over time...


Thanks,

-Chris

[infiniti_guy]

On areca...

They have PCI-e versions of their cards, and while they are really expensive (compared to others), they are also supposed to be really fast. I have open questions with Areca, but they have indicated their cards will work in an SLI MoBo configuration.

It looks like other major players are also working on PCI-e RAID cards.. to be released towards the end of the year.

[mdmint]

Originally Posted by infiniti_guy

2) ECC RAM - I was thinking that the ECC would help under the situation of multiple large file transfers, but it may have an effect on Client video performance. I still have a little bit of occasional choppiness of video (not always, but after time), and I was wondering if the ECC casues some type of memory backup over time...

Having a RAID controller with cache memory, and having write back cache policy set enabled, can make a big performance difference with concurrent multiple recordings and simultaneous playback using Sage. I've tested my 9500S-8 with and without writeback cache enabled. If 4 or 5 recordings happening playback is a bit choppy with write back cache disabled, enabled smooth as silk.

ECC memory is a totally different issue that primarily has nothing to do with read or write performance. ECC is an error correcting type of memory. If controller supports it it's a memory error correcting feature that enables recovering from a single bit memory error. Non ECC memory if getting a memory error normally halts operations while ECC memory allows operations to continue.

[infiniti_guy]

Thanks mdmint.

I was wondering about performance aspects w/ECC system memory... Is anyone running ECC on their board with success in Sage?

[infiniti_guy]

Also, what do you guys think of PCI-e solutions for RAID in Sage? Is it worth the price difference? It's a big difference in platform. For MoBos, the # of PCI slots gets reduced to 3 (ASUS A8N-SLI) with SLI (required for RAID on PCI-e slot).

[mdmint]

Originally Posted by infiniti_guy

Thanks mdmint.

I was wondering about performance aspects w/ECC system memory... Is anyone running ECC on their board with success in Sage?

Yes, failed to mention running ECC memory on my 9500S-8. But the point I was making is that ECC memory does not make a difference performance wise! The performance difference comes from having controller hardware cache memory (ECC or non ECC) and enabling write back cache.

[mdmint]

Originally Posted by infiniti_guy

Also, what do you guys think of PCI-e solutions for RAID in Sage? Is it worth the price difference? It's a big difference in platform. For MoBos, the # of PCI slots gets reduced to 3 (ASUS A8N-SLI) with SLI (required for RAID on PCI-e slot).

Performance difference yes, but as far as Sage usage goes likely not IMO. However, I can only speak from using a lowly 3ware 9500S-8 configured 8HDs RAID5 (inc online spare) successfully testing 5 concurrent Mpeg2 Max Quality recordings with 3 simultaneous smooth playbacks to Clients of previously recorded Standard DVD Q.

Is it worth the price difference? Only you can decide that. Truth be told if I was building now I'd consider it! Who knows when the need for more storage speed will come into play.

[infiniti_guy]

Originally Posted by mdmint

Is it worth the price difference? Only you can decide that. Truth be told if I was building now I'd consider it! Who knows when the need for more storage speed will come into play.

Those are my conerns as well... I am just thinking about when we implement HD into our servers... it should be ok (theoretically) w/PCI, but under some configs it might cut it a little close to the PCI bandwidth.

On the other side, I don't know how stable it would be to run such a platform since everything is so new w/PCI-e.