Opinions on MotherBoard Raid

[trini0]

I was going to do a similar setup to what Toxmox was doing in this thread ->
http://forums.sagetv.com/forums/showthread.php?t=20397
The budget got cut, and Im looking to cut corners.
I need to have raid 5 storage available to the network.
I've never used a motherboard's built in raid.
Looking to see what your opinions are on this matter.
Thanks

[stevech]

Based on what I've read, you might check if the motherboard RAID5 is in fact software RAID, or maybe BIOS firmware, meaning the chipset can do concurrent read/write to two drives at once for RAID1, but RAID5 is faked.

I am not sure, but I suspect this is what's done to avoid a $400 RAID controller.

[silkshadow]

I ran mobo raid 5 on a MSI K8N Neo4 Platinum for a couple of months which comes with a SiI 3114 controller. I wrote about it somewhere on this board, actually. When I was looking into it, only high end server boards came with raid 5 that wasn't software raid. For those boards, you wouldn't be saving any money. If you want raid 5, you need to look for a mobo that has enough ports on the raid controller. There were other boards, at that time, that came with the SiI 3114 but only had 2 ports, which is not enough for raid 5. I don't know what's out there now, as I got that MSI more than a year ago, but I do recommend the board that I used.

I am not so sure you want to use the mobo raid 5 for Sage recordings. It works but it does sometimes run a bit too slow so there are hiccups in the recording. However, using it for storage (mostly read access) is just fine. Error recovery is also fine. I had one drive fail on me and was able to swap in another one with no issues. I have since gotten two Promise PCI-E hardware raid 5 cards. I was using the software raid as a stopgap till PCI-e raid 5 cards (besides the Areca) came to market. However, if you don't need performance, or don't plan to do much writes to your array, I don't see any issues with using mobo raid5.

[Lucas]

Mobo RAID is usually software raid, something that pushed me away from using it.

Hardware raid controllers for ATA / SATA drives are going pretty cheap on ebay and even previous year tech is very reliable and can be used to implement cost effective raid 5 with solultions like NASLite.

[nielm]

IMHO There is no point in RAID0: even hdtv is less than the sustained read/write time for modern hdds, and sage can be configured to get each tuner to wite to a separare disk. Also it's too fragile (your array has half the MTBF of a single drive)

I am currently using hardware raid1 (SI3114 on an asus nforce3 mobo) for my archive drives. It can do raid5 with a sw/hw combo, but the sys requirements said it needed 1GB of RAM to do it!

However, I am starting to wonder whether any RAID is atually worth it... I have heard stories of controllers dying and destroying all data on all drives, or the controller getting confused about which disk is good and rebuilding the mirrorset from a blnk drive! Also it does not recover from 'human' or SW error (deleting files by error)...

I suppose If I was starting again, I would just do regular backups to a separate drive onto a separate machine or NAS! Ideally, I would have RAID1 *and* regular backups,but it seems a bit of overkill!

I guess you need to look at what you are trying to protect, and what you are trying to protect it from... For me, I am protecting the time taken to rip DVD's and MP3's, and the contents my digital photo archive, from user stupidity, hardware failure, and also from catastrophy (fire/theft etc)

So these are on RAID1 on the server, with a second copy of the MP3's & photos on a second system, and 'offsite backups' of the photos wrtten to DVD-Rs, and locked in my office desk!

[perfessor101]

I have an HPT 374 raid controller on a Abit An7-Max motherboard and found that with Maxtor drives model number 6L250R0 I was getting unpredictable dma errors whether I was using the drive as a single drive, JBOD or software raid 5 (in windows XP, windows 2000, Gentoo, Centos, Debian). Maxtor drive model 6B250R0 works rock solid though.

I'm currently looking to get an actual raid card as I only have two 6B250R0 drives and 3 6L250R0. (also the 6B250R0 drives aren't even listed on the Maxtor website anymore, hmmm ....)

Bobby

[trini0]

Thanks for your input.
I'll try and bit the bullet and get a dedicated card to do this job...

[Mark SS]

Originally Posted by nielm

However, I am starting to wonder whether any RAID is atually worth it... I have heard stories of controllers dying and destroying all data on all drives, or the controller getting confused about which disk is good and rebuilding the mirrorset from a blnk drive!

This appears to be what happened to me last week. nForce4 mobo using RAID1 where a drive has dropped out of the array on occasions. Who can tell if its a faulty drive, if so which drive, or if its the motherboard!

I suppose If I was starting again, I would just do regular backups to a separate drive onto a separate machine or NAS! Ideally, I would have RAID1 *and* regular backups,but it seems a bit of overkill!

As the HTPC is the entertainment hub for the whole house, the point of RAID for me was to minimise the risk of having no television due to a drive failure. I'm considering switching to a proper RAID card, rather than mobo features, and using level 5 rather than mirror. At least that way one would assume it can't cock up a rebuild of the array!

[dagar]

I have a M2N32 WS Professional mobo in my server
http://usa.asus.com/products4.aspx?l...07&modelmenu=1

The Nforce 590 RAID 5 is craptacularly slow. Was running 6 320GB drives, it's now in RAID10 config ... MUCH faster (obviously). The RAID 5 implementation is about 5mbs or so for transfer. That is a non-functional solution IMO. A 12 or 24 port Areca is on the horizon

[StephaneM]

I personally have a P5WD2 Premium with ICH7R chipset with RAID support. I'm currently using a single RAID 5 array (3 SATA II 250 GB drives).

Even though RAID 5 write performance is not that great (10 MB to 16 MB / s), I do find it plenty enough for HTPC usage. I can record three SD shows at once.

If you do want to record HD shows, it should be also Ok, if I'm not wrong, HD show should not be more than 22 Mbits / second. And what the ICH7 RAID 5 will give you is approx : 60 to 120 Mbits / second : enough for recording three HD shows at once.

Also with ICH7R chipset there is a "Matrix Raid" option: you can setup with 3 or 4 drive, one RAID5 array and one RAID0 array. On the RAID5 array you'll put everything (system, video, pictures etc...) and you'll made the RAID0 array your recording drive. This way there is no bottelneck performance when dumping videos from your captures device to the drive.

The only thing to do will be to move recordings from the RAID0 array to the RAID5 array upon recording completion.

Finally you have :

* a full redondant drive with good read performance
* a "temporary" drive with very good write performance (thoug if one of the drive in the array fails : you loose this drive and it's content, so use it only as a recording drive, for instance I would not put the windows page file on it especially if you have many GB of RAM because I don't know how Windows will react when you loose the paging file drive).

Regarding reliability of the RAID5 array : for me it is reliable, but you have to be careful. For instance, you must have an UPS device, because if the power the array will rebuild itself (no data loss, but it took at least 8 hours to be done, though the PC is still usable even for watching TV). The same thing may happen if you PC crash (unexpected windows reboot). The only real problem is when your array is rebuilding and you PC crash or loose power, the array will fail, but you'll be able to recover it by installing Windows on a temporary drive (IDE) and with the Intel Matrix Storage manager you can fix it (allthoug this shouldn't happen any more with recent bios of the ICH7R).

So I really don't see any objections for using RAID5 (at least with Intel chipset) on an HTPC. The only thing that is very slow on my config is when I use the windows defrag utiliy : disk transfer is very very slow and this may affect overall PC performance.

Regards,
Stéphane.

[stevech]

Originally Posted by nielm

I suppose If I was starting again, I would just do regular backups to a separate drive onto a separate machine or NAS! Ideally, I would have RAID1 *and* regular backups,but it seems a bit of overkill!

I agree with you re ordinary photos and so on, but doing backup of video recordings, as daily incrementals or weekly full backups, is impractical due to the data volume. I want to move to RAID1 in hardware, but I hadn't considered the possibilities you raise earlier here - such as how likely it is that the failed-drive recovery may well wipe out the good drive. Suggestions welcome on robust firmware/controller stuff, or is this a Windoze issue?

[GTwannabe]

Originally Posted by stevech

I agree with you re ordinary photos and so on, but doing backup of video recordings, as daily incrementals or weekly full backups, is impractical due to the data volume. I want to move to RAID1 in hardware, but I hadn't considered the possibilities you raise earlier here - such as how likely it is that the failed-drive recovery may well wipe out the good drive. Suggestions welcome on robust firmware/controller stuff, or is this a Windoze issue?

I use the onboard Intel RAID-1 on my PowerEdge workstation. A few months ago, I started having random system lockups and BSOD's. Turned out that one drive in the RAID-1 array was becoming flaky and crashing the system. Unfortunately, the BIOS array status still showed the drive as "Healthy" and no events were being logged in the Windows Event Manager.

Now with a hardware RAID controller, that won't happen because the RAID card isolates the faulty drive from Windows. The motherboard solutions tend to just mask the drives as a single drive, then stripe (RAID-0) or duplicate (RAID-1) data to them. Haven't been able to play with anything with mobo-level RAID-5 yet.

As far as accidentally nuking your array during rebuild, it isn't too likely. Just pull the faulty drive, add a new one, configure the new drive as a hot spare, then start the rebuild.

[stevech]

can I expect hardware RAID1 in $100 mobo's today? What chipset? Looks like the latest ASUS AM2 (I'm an AMD supporter for the sake of competition) - have RAID only on the SATA ports, and not on the IDE ports, suggesting it is in the chipset.

[trini0]

Originally Posted by stevech

can I expect hardware RAID1 in $100 mobo's today?

Yes you can, and more ->
http://www.newegg.com/Product/Produc...82E16813130049

How good is it. Well thats the reason why I started this discussion...