Recommend me a RAID card

[FishAk]

Anyone??

Thanks

I sure like my RAID 10 array. It's as expensive as RAID 1 for disk space, but it does have quite a bit better performance that I can feel over both single disk and RAID 1. I'm just using the ICH10R controller, so it's just fake RAID, I suppose. The only trouble I have is that I'm using Western Digital drives, which occasionally drop out of the array. I didn't know any better when I bought them.

Keep in mind that no RAID array is the same as backup. Make sure you have and maintain a backup set, before setting up an array.

 

[RaiderJ]

All the technical points aside (which I agree with), running RAID5 with 4x1TB or 4x2TB disks will be fine. Just assume the array will *help* protect you from drive failures, not prevent data loss.

Anything that you can't live without should be backed up someplace else anyway.

 

[bad_monkey]

I would go with RAID 10 which is a striped set of mirrors. (a1 and a2 are mirrored creating a', b1 and b2 are mirrored creating b' and then a' and b' are striped). Fairly reliable, you have 1/2N * size storage. (4x1TB = 1/2*4*1 = 2 TB) and performance is pretty good. Read is ~= RAID5 and write is >= RAID 5.

If you are not using this for an enterprise environment then you don't need a $300+ raid card. Check out RocketRaid.

 

[bad_monkey]

All the technical points aside (which I agree with), running RAID5 with 4x1TB or 4x2TB disks will be fine. Just assume the array will *help* protect you from drive failures, not prevent data loss.

Anything that you can't live without should be backed up someplace else anyway.

Agreed and I don't want to speak for FishAK but I am sure he would as well.

 

[i0's]

I was just going through with all my options and suddenly it hit me that my motherboard can do RAID too. I dunno why I did not think of this first, maybe I have always associated RAID with independent RAID cards.

Well anyways, I have a Intel DG965WH motherboard and according to Intel's website it supports RAID 5 both with and without write-back cache, http://www.intel.com/support/motherboards/desktop/sb/cs-020811.htm

With that, can I just use my motherboard's RAID and use RAID 5 with write-back cache to negate the BER issue, that high end RAID cards provide?
The computer itself has 4GB RAM and has a UPS attached to it, if it helps.

Thanks

 

[FishAk]

With all the technical points aside, there are countless posts by people asking for help recovering their RAID 5 data. As long as you keep your data backed up, and can simply delete and rebuild your RAID set from the backup, any RAID is fine.

With disk space so cheep, the cost between RAID 5 and 10, or 01 is fairly small. I haven't personally used RAID 5, but from many of the accounts I've read, it can be slower than using single disks. I understand a good RAID card can give speedy performance, but other methods- not so much.

So for me personally, considering the expense, the reliability, and the performance, I remain unconvinced that RAID 5 should be considered as an option.

 

[Rifter]

RAID 5 is not so bad, im running a 3 disk array(seagate 1.5TB LP's) under linux and its fine. Been running for over a year now no dropouts or problems so far, its about 60% full.

Windows based software raid tends to be hella slow from what ive seen but i can put down 70-80MB/s+ reads and writes which is fast enough for gigabit so its fast enough for me. I back it all up monthly to a 2TB drive in another computer. As long as you have a backup RAID 5 is fine.

 

[FishAk]

Ok, I didn't think about this. If like Rifterut, you're bottle-necked by your connection, and you don't use the array directly, than a performance loss is insignificant, and an additional drive can be saved. In this case, I would consider RAID 5 as an option.

 

[i0's]

So would you guys recommend I use my motherboard's RAID feature to build a RAID 5 with write back cache enabled then?

Cheers

 

[RebateMonger]

With all the technical points aside, there are countless posts by people asking for help recovering their RAID 5 data. As long as you keep your data backed up, and can simply delete and rebuild your RAID set from the backup, any RAID is fine.

This.

I've seen several companies lose their data when using RAID 5 and I've never seen anybody lose data with RAID 1. Personally, I haven't built a RAID 5 array in five years, except as a simulator to help people recover their lost RAID 5 data.

If you want uptime, I recommend RAID 1. If you want uptime plus an extra speed boost, I recommend RAID 10. If you want to avoid data loss, make backups. Disks are cheap and lost data is expensive.

But as long as you keep good backups, feel free to use whatever RAID system tickles your fancy.

 

[bad_monkey]

If you have other backups RAID5 is nice volume wise because you only lose one parity disk worth of space. RAID1 or RAID 10 which I also recommended suffers a 50% loss. RAID5 does incur a write penalty. If you aren't worried about that then roll with it.

 

[Mark R]

So would you guys recommend I use my motherboard's RAID feature to build a RAID 5 with write back cache enabled then?

Cheers

Motherboard integrated RAID is the lowest of the low grade RAID systems you can buy. They have no support for write-back caching, and use very poor algorithms for optimising write speeds in RAID5 (in order to minimize RAM consumption, which would otherwise be blocked from OS use).

Motherboard RAID 5 write speed is often so slow as to be unsuable - think 10 MB/s (slower than a USB external drive, or even a memory stick).

 

[alaricljs]

Motherboard integrated RAID is the lowest of the low grade RAID systems you can buy. They have no support for write-back caching, and use very poor algorithms for optimising write speeds in RAID5 (in order to minimize RAM consumption, which would otherwise be blocked from OS use).

But as io's said earlier, his mobo DOES support the write-back caching, at least that's his impression from the intel support page he linked to.

io's: Build it and test it out, if it's good enough for your needs then go for it.

 

[bigi]

Anyone??

Thanks

Because:

1. It is reliable and widely used in server grade hardware.
2. It is very highly configurable in its web management tools.
3. Its RAID5 is fast compared whatever else you can find - both reads/writes.
4. It has BBU which further enhances its reliability.
5 It connects via multiport SATA cable that reduces cable clutter.
6. It provides raid migration, expansion. It provides carving too.

 

[Rifter]

So would you guys recommend I use my motherboard's RAID feature to build a RAID 5 with write back cache enabled then?

Cheers

no, if you are going to go software RAID then stick to raid 0 or 1. If you go software RAID 5 then linux is really your only option if you want to get anything but crappy performance.

 

[markrb38]

nm

 

[theevilsharpie]

3ware 9650 4MPL. It is $320, which is not cheap, but I'll provide best RAID solution in industry.

As someone who owns said card... lulz.

 

[ElenaP]

I've made a spreadsheet which can be used to calculate the risk of data loss while allowing multiple parameters to be varied. The basic assumptions are:
1. Uncorrelated drive failures
2. Only drive failures considered
3. Complete capacity rebuild
4. Unlimited spares (even if there are no hot spares, you can still order a replacement in - in which case recovery time might be 1 week).

There is one more assumption involved, about the uniform distribution of failures. The calculation assumes that the fact of encountering the first read error does not change the probability to encounter the next one, and also that the probability of read errors does not change over time.