newbie RAID questions

[umbletech]

Guys I have a few questions to ask. Regarding the ML and DL families:

1. AIS book talks up ADG technology as being better than raid 1+0
How does it work?
Has there been much uptake of it?
Are there any disadvantages?

2. What's the difference between Insight manager and Systems Insight Manager
What are the current versions?


3. AIS book says all drives on a controller should be in one array. Now a lot of people have a mirror for the oS and RAID 5 or 1+0 for the data. Does this mean you

4. Probably related to question 3. In the old days you always used used to use the separate controller cards in preference to using onboard SCSI controllers.
Do many of the ML/DL series servers have onboard RAID?

5. Mixing SCSI and SATA RAID - is it advisable? If so what series of servers can you do it on?

6. AIS book says S.M.A.R.T. disk drives will tell Insight Manager of drive problems. How are nofifications handled - can insight manager email you?

Sorry for all the questions - a link or two would be great - not too used to the HP site yet and all the HP books I have are a couple of years old.

 

[AndrewTait]

In answer to question 6. Instight manager can mail you over any of the things it manages. You can also have different people being e-mailed about different errors.

At my current workplace, all IT staff get notified if a server goes off line, disk fails, processor overheats, NIC goes off line.

Only some people get mailed about failed processes monitored by insight manager, and about driver updates.

My last place all IT staff got all e-mails.

=======================================
So often times it happens that we live our lives in chains
And we never even know we have the key

Ne auderis delere orbem rigidum meum
======================================

 

[umbletech]

Thanks Andrew

Just to add value to the thread I got this reply on another forum:

Two key things:
1) SATA is completely different from ATA in one detail - there is always one drive per channel as it is a point-to-point architecture; hence no more buses, master-slave & all that stuff! Just a thin cable form a controller / MB to a drive.

2) If you are referring to an embedded SATA RAID controllers available in some entry-level HP servers, bear in mind they are something in betwéen harware & software solution. From the OS perspective it is a hardware solution (e.g. no OS-level mirroring / stripping) but you need to run a driver from a floppy to make the RAID working.

But I'd still like to know what are the common configs - eg. is it Ok to run a SATA mirror off the onboard for the OS and put in a 6i for the data RAID or is it better to run everything off the 6i?

 

[cdove]

Raid ADG (Sdvanced Data Guarding) works similar to Raid 5 but allows you to lose 2 disks from the array before you lose all data stored on them. I can't personally see and disadvantage of tghis apart from you'll effectively need another disk in the array

 

[wahnula]

is it Ok to run a SATA mirror off the onboard for the OS and put in a 6i for the data RAID or is it better to run everything off the 6i?

It's always good to separate OS & apps from data. Putting them on separate arrays is best.

 

[umbletech]

Thanks Wahnula

Agreed but the question was more about mixing SATA and SCSI. Seek times are about 4 millisec for 15K SCSI and 9 for SATA. Does it make a big difference in your normal 50 to 100 seat site? And reliability?

 

[rliebsch]

1: I think RAID1+0 is going to be faster. Hands down. ADG is a RAID5-ish configuration. RAID5 is only about 57% efficient. I think even the wizards tell you that it is more for redundancy rather than performance.

4: my personal experience, the onboard controllers are pretty slow/weak. But, you could run your OS/binaries on RAID10 on that, then get another controller for an external array

and about 50 to 100 seat site; it really depends on the application. I have 50 users using Entourage to access Exchange on a DL385 with a 6404 controller and a 14 drive array. They are crushing it... When they were on 4 internal drives on the 6i controller, they were killing it, massive latency, long read and write times, disk queues over 300.



Robert Liebsch
Stone Yamashita Partners

http://www.stoneyamashita.com/

 

[umbletech]

Thanks Robert

That clarifies the RAID configs. What I was curious about was SCSI vs SATA