raid question

I'm pretty sure that they won't install OS on RAID or even enable RAID for you.... You might need to reinstall/enable RAID yourself if you need it.

For the 8890 it is probably a setting in the bios to enable the RAID of the drives. According to the specs it RAIDs the main drive and the selectbay 2.

In any case, it shouldn't be too difficult to setup.

Raid doubling your storage?

My real question on raid is this...
With Raid 0, you get your data essentially spit in 2... so it reads faster since it spreads it over 2 drives... great.. so does that mean that with 2 60 gig drives, I'm actually getting 120 gigs...
In raid 1, it would be 60 gigs, with the second drive just backing up/mirroring the first, but with raid 0, I should be getting 120 right?
Bob

For a RAID 0 stripped array you get:

- A drive that appears to have double the storage capacity of your SMALLEST drive in the array if you have a 40 GB and 60 GB drive in the array you'll have what appears to be an 80 GB drive and 20 GB of lost space.

- A drive that appears to be slightly slower than 2x your SLOWEST drive in the array.

In the configuration that the 8890 will be sold in if you get 2 60 GB drives with 8 MB cache and 7200 RPM spindle speed you'll have a 120 GB drive with 16 MB cache and a near 14400 spindle speed.

Yupp, if you have 2 60gig drives it will appear as 1 120gig drive in a Raid 0 setup.

Yes, it will "come with Raid 0" if that is what you're asking. It is a setting in the BIOS (more than likely) that you simply turn on. All 8890s will feature this. You have it somewhat right, you'd have to 60Gig drives with 8MB cache each (effectively 16MB since data is split), but you would not effectively have a 14400 spindle speed, you'd have dual 7200RPM and the latency associated with it.

Its like was said in another thread, if you have dual 3Ghz procs in a PC, you do not have a 6Ghz PC you have a dual 3Ghz.

Whether it comes setup or you have to do it yourself depends on the vendor. Some vendors will setup RAID and install the OS on it for you, others won't, I'm sure.

Ayasin was completely correct about the aspects of RAID 0. With hardware RAID-0, such as supported by the 8890, operation is completely transparent to software, the software only sees one large, high-speed disk. So installing the OS on it is no propblem.

The equivalent statistics to what Ayasin gave, but for RAID-1:

- A drive that appears to have the same capacity as the smallest drive in the array. So if you have a 40 GB and a 60 GB drive in the array, you'll have what appears to be a 40 GB drive and 20 GB of lost space. (That 40 GB is mirrored, so occupies another 40 GB, bringing the total to 100, the combined capacity of the drives).

- A drive that, on writing, appears slightly slower than the slowest drive in the array.

- A drive that, on reading, appears slightly slower than the fastest drive in the array. (Assuming the controller is smart enough to pull the fastest copy. RAID-1 has no way to determine which copy contains errors in case of discrepancy, so there's no reason to compare the data to what's on the slower drive).

If you use two identical drives, a RAID-1 configuration looks to software like a single one of those drives.

-phubar

So if you had 2 drives with RAID 1 you could remove one and still function correct? cause you'd be removing the backup copy drive.

But with Raid 0, if you removed one drive, all hell breaks loose cause you just removed 1/2 of the data for every program and application you have ever installed. Damn.


All in all, this RAID stuff sounds pretty cool

Exactly. In fact, with RAID-1, you should be able to remove one drive and replace it with a blank one, and the RAID controller will copy the entire other drive over to the new blank disk to make a mirrored copy. It's a quick way to make disk copies.

Raid 0, if either drive goes away, you're left with half your data. In fact, you're left with every other unit of data (probably every other sector), so the entire disk is useless gibberish.

-phubar

Raid
0 AKA disk striping requires 2 drives
pros: speed cons: not fault tolerant

1 AKA disk mirroring requires 2 drives
pros: fault tolerant cons: no speed increase

5 AKA disk striping with parity 3 drives
pros: fault tolerant, speed increase cons: need 3 drives!

If a RAID 0 fails your screwed you can't recover you data
If a RAID 1 fails you switch to the other disk and put in a new drive and the RAID controller mirrors the working drive to the blank one

If one disk of a RAID 5 fails you can still work with 2 disks as the RAID controller and rebuild the data from the parity and remaining data, at reduced performance of course. Each drive contains data and parity information. After replacing the bad disk the RAID controller will rebuild the failed drive.

RAID 0+1 is popular because the controller doesn't have to calculate and write the parity information, so there is speed increase. If one drive fails you have a mirror back-up of it.

If the 8890 has a hardware RAID controller as opposed to using Windows software for RAID. The speed increase will be realized. I haven't been following the specs on the 8890, hence my ignorance.

I've been using only one H.D. and had to send my 9890 back for repair and got them to install another H.D. so I could use Raid 1 configuration. What do I need to do to get it going?
76TR6

BigBoy, if you are planning on installing your own OS and setting up a RAID 0 yourself you should know it can be a litle tricky. I recommend doing a search on these forums about it.

Basically, you have to install the RAID drivers from a floopy. Since most laptops don't come with an internal flaoppy drive anymore you'll need to make sure you get an external version and that it is enabled in your bios. Again, there is detailed information about this elsewhere in the forums.

Lastly, if you are planning on using RAID 0 on your lappy I strongly recommend weekly back-ups to a large external hard drive. Laptop drives are slightly more prone to failure than desktop models, a tendancy made even worse by the abuse that laptops endure. Since you have two hard drives you now have twice the chance that *one* of them will fail, scuttling *all* your data.

There's detailed instructions elsewhere here but, in a nutshell, you have to enable RAID 1 in your bios and then install the RAID drivers using an external floppy drive. I've never used RAID 1 before so I don't know if it will automatically write all your existing information from your original drive onto your additional drive or if you'll have to back-up, re-install your OS and apps, and then reload your files.