SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Technology Stocks : Network Appliance -- Ignore unavailable to you. Want to Upgrade?


To: JRH who wrote (3153)4/25/2000 1:52:00 PM
From: pirate_200  Respond to of 10934
 
> I talked with my friend a bit more and have some
> clarifications on my original post. Apparently,
> their Filer did not have the capability to hot
> swap the bad disk with another good disk. Instead,
> RAID 5 rebuilds the disk when it fails, which uses
> up a lot of CPU and time. With RAID 0+1, which their
> SAN device uses, the drive that failed can
> be pulled out and replaced. Not so in RAID 5. Do you
> have any references for your statement above? I hope you're
> right and my friend is wrong <gg>

NTAP uses RAID4, note RAID5. In any RAID configuration,
you have to rebuild the drive that is replaced - even
when doing mirroring, where a complete copy of the drive
is kept, when you replace the failed drive it needs to
be rebuilt.

NTAP *does* hot replacement (hot swap) also, so that
statement is bogus.

You might want to get the exact quote from your "friend"
sounds like something is getting mangled in the
translation.



To: JRH who wrote (3153)5/10/2000 4:37:00 PM
From: DownSouth  Read Replies (4) | Respond to of 10934
 
their Filer did not have the capability to hot swap the bad disk with another good disk. Instead, RAID 5 rebuilds the disk when it fails, which uses up a lot of CPU and time. With RAID 0+1, which their SAN device uses, the drive that failed can be pulled out and replaced. Not so in RAID 5.

Your friend needs to do some studying before being a part of such a decision. NTAP absolutley does hot swap a bad drive. I does rebuild the contents of the failed drive to the new drive (which was sitting ready for use) using RAID parity techniques. Sys admin controls the amount of CPU resource allowed to be used in the rebuild. It can be as low as 10% or as high as 90%.

NTAP does not use RAID 5. It uses RAID 4, which also allows the user to grow a RAID array simply by adding a drive with no file rebuild as required by RAID 5.

"RAID 0+1" is not RAID at all. Though I am not sure what "0+1" means, as that is not a RAID term, it sounds like they are using Mirroring, which is very expensive and also slow, as all writes are duplicated.

What your friend lost-
Speed, Reliability, Simple sys admin, multi-protocol (NT/UNIX) securit, SNAPSHOT/RECOVER, addition of clustered configurations, simple growth.

What your friend gained-
Nothing, but probably at a higher price.

This is more than just my opinion.