SATA Bridge and RAID5 Reliability

[LhasaCM]

I'm starting to move away from just having a bunch of drives in my personal PC to a more regimented setup, but have a few concerns about making the transition cheaply (so as not to upset the wife) but also correctly.

Right now, I have two 400 GB Western Digital SATA drives plugged into 2 of the 4 ports on a SATA RocketRAID 1640 card, and two 400 GB Seagate IDE drives connected to the motherboard (Asus P4P800SE - the onboard SATA ports are being used for a pair of 74GB Raptors - one for the OS/Applications, and one for Games). What I'd like to do is use something like this to hook each IDE drive into the RAID card and set up one large RAID 5 array.

I'm not overly concerned about performance - the drives eventually will be tucked away in a closet in a media server hosting ripped DVDs and recorded television, serving up to a Sage TV Media Extender and maybe one PC. (Television will be temporarily recorded to a separate drive, but moved to the array once I've stripped commercials.) However, I would like to ensure as much as possible that my cheapness isn't introducing a major risk of a lack of reliability in the array. Has anybody used these types of bridging boards in the past with success/failure? Any other thoughts?

 

[Lazn_Work]

I have not used one in an array, but I used one on a stand alone drive for almost a year because of cabling issues in my case. I had no problems with it.

It is one more part that can fail though.. so it is your call.

Also are those WD drives RE drives? If not, you dont't want to use them in a RAID 5 setup because of their TLER issue.

==>Lazn

 

[LhasaCM]

I had no problems with it.

Good to know - thanks!

Also are those WD drives RE drives?

Negative. The WD drives are WD4000KD retail packages. BTW, the Seagates are model ST3400632A (again, retail packages)

If not, you dont't want to use them in a RAID 5 setup because of their TLER issue.

Speaking from a position of relative ignorance, wouldn't the TLER issue also be an issue with the Seagate drives, as they are not "specially designed to exist in a RAID array" like the RE line of WD drives? Obviously, were I to buy new drives or revisit the decisions I made before this point, I would have done a better job to make sure I got the RE drives. However, being where I am now, how much of a problem is it not to have the TLER features?

I was reading WD's marketing/technical fact sheet on the issue (found here) and my interpretation is that the risk is greater in a high volume or I/O environment. That won't be the application here, so could I be relative safe?

 

[Lazn_Work]

Speaking from a position of relative ignorance, wouldn't the TLER issue also be an issue with the Seagate drives, as they are not "specially designed to exist in a RAID array" like the RE line of WD drives? Obviously, were I to buy new drives or revisit the decisions I made before this point, I would have done a better job to make sure I got the RE drives. However, being where I am now, how much of a problem is it not to have the TLER features?

I was reading WD's marketing/technical fact sheet on the issue (found here) and my interpretation is that the risk is greater in a high volume or I/O environment. That won't be the application here, so could I be relative safe?

Well WD retail drives have longer error recovery times than other MFG's. This is a good thing for desktop drives, but a bad thing for RAID arrays.

As for if the Seagates will have the same problem, I don't know how long they keep trying to read a bad block, and how that time compares to WD drives, or RE drives. ( Edit: they also make RE type drives:http://www.seagate.com/products/enterprise )

 

[LhasaCM]

So - would I be better off/safer in setting it up as I have it now as just a bunch of disks, or would software RAID be an option (in Windows, so something along the lines of this guide)?

Granted, what I'll likely do is just try it in hardware and see if it works for me (since the SATA bridge shouldn't be much of an obstacle), but it's always nice to have some rational expectation about the likelihood of failure (I'd rather be stupid than ignorant )

 

[Lazn_Work]

Honestly I don't know. If I were you I would give it a shot with the hardware you got, run some intensive benchmarks or some such to see if it behaves.. No guarantee, but it might be enough for your use.

 

[unhappy_mage]

Speaking from a position of relative ignorance, wouldn't the TLER issue also be an issue with the Seagate drives, as they are not "specially designed to exist in a RAID array" like the RE line of WD drives?

WD has come out with a lot of propaganda WRT TLER. TLER is (as far as I've been able to determine!) a WD-specific problem with the firmware. Some of the entries in that thread seem to indicate that other manufacturers have the problem, but I'm trying to play it safe in that thread and give only completely verified, manufacturer-certified information. In actuality, I haven't heard of anyone dropping disks with any company but WD, and I've heard of several instances of that. That seems pretty definitive to me, without doing any statistical analysis

 

[LhasaCM]

Thanks all, for your help. I think I'll go with the "try it and cross my fingers" approach. What's the worst that could happen?

 

[Farva]

Thanks all, for your help. I think I'll go with the "try it and cross my fingers" approach. What's the worst that could happen?

dropping 2 disks without backups and "poof" goes ur data

 

[LhasaCM]

dropping 2 disks without backups and "poof" goes ur data

Exactly...that's not so bad, is it?

In all seriousness: I'll be using the array to hold ripped DVDs and recorded television. I won't go through much effort to fill it until I'm reasonably confident that it can handle the load for a few weeks - hopefully, if there's a structural problem it will manifest itself upon launch rather than rear its ugly head down the road. Anything I don't own the media for or had to go through too much effort to make nice (i.e., recorded TV) will be backed up elsewhere anyway, so all I'd be out if it does fail is a lot of time and an angry wife for having to waste more time on the "stupid computer."

 

[Aronj66]

As long as the sata controller works with the bridge cards you should be ok. Though in general its not a good idea to mix drives in raid arrays. I have an array of 6 wd 120gb sata drives and have had no issues with the array.

I've been using these bridges in my systems, though not on raid arrays and like them.. syba