Poweredge Perc6i

Yes, you can do the setup you refer to. Why would you run either a single or multi disk raid 0 for the OS, a loss of which creates unnecessary hardship ?

 

 

Dollars is the only why.  It's no problem to justify RAID for data, but the OS can be rebuilt or ghosted. Software or hardware mirroring is an option here, the main thing I want to do is get the OS on a different array than the data.

This setup is different - if I'm in the right location for the setup.  With HP setup, you highlight the physical drives, create an array, then create virtual drives that the OS sees as drives.  I don't see where to create an array, only virtual drive - is this dell's term for an array?  I don't want one huge drive!!  I have 4/ 146gb drives, I want a RAID 10 array to then create 3 or 4 drives. I don't see any tutorials for perc 6/i

 

I've put in the system manage CD and used (Ctrl+R) at startup.

 

Yes a Virtual Drive is an array. Look at this documentation on more information on setting an array.

Look under the section "Configure virtual disks". Though that is for the PERC 5, they are pretty much the same if I am not mistaken. The PERC 6 just adds support for RAID levels 6 and 60.

Also, if you intended to setup the array in the controller's BIOS, then when you boot to the Dell System Build and Update CD, skip the array configuration part. What I would recommand to do is create the RAID 0, install the OS and then after the installation is done, create the RAID 10 either in the controller's BIOS or using Server Administrator within the OS. You can setup the array while in the System Build CD though. Just make sure that when you select the RAID level 0, the proper drives are selected and not all of them.

Oh and aren't they worried about downtime? If your OS goes, then there's no access to data... And if this is a standalone sever and that was to happen in the middle of the day, I'd bet they would wish a spent a bit more for one extra drive... Just a thought ;)

You're right, I agree! I've just had to go step by step, very slowly in getting dollars for this server, probably so slow it's more difficult now.  I'll get there, just going in steps and getting familiar with this Dell setup.

 

Management problem here, not technical - new company, budget communication is poor -  I started too small in my proposal, more dollars were available than I thought. So, as I have realized we can spend more it's been in increments - now I'm trying to avoid "another" addition.

 

I should have proposed what we needed in the beginning and worked down from there if the dollars were too high.

 

 

"Software or hardware mirroring is an option here, the main thing I want to do is get the OS on a different array than the data."

If software or hardware mirroring is an option, go for the extra disk....I have set up raids for >20 years and having a hardware raid 1 is the economical way to go; do not even consider software raid.  Even if you can restore from a tape or clone fairly easily, the time required, lost productivity, the aggravation, and at times lost sleep, would more than pay for the cost of a disk.

 

"I should have proposed what we needed in the beginning.."

Almost everyone is guilty of this. If I know the client has limited resources, I ALWAYS cut it a bit short.

At this point as a Consultant, I can not afford array failures, I end up eating time in these situations... unless it is totally the clients fault.

 

Why I harp on raid 1 for the OS....

 

A few years back I had a raid server crash due to a very necessary firmware update to Seagate disks (major bug), which proceeded to destroying the array (multiple Seagate techs assured me it was totally safe; not that I believed that).

This particular server was build in 1999, and due to budget constrains, the OS and data were on one big SCSI raid 5 (SCSI drives were real expensive at that time).

Well, this Active Directory FSMO server had SQL with open files when it crashed. Even with a successful tape restore, and a successful authoritative AD restore, I was up 36 hours straight, had 6 hours of sleep, then another 36 hour straight day to get the SQL based programs running with no data/security issues.

I NEVER EVER want to experience that again. 

 

If I had the OS and SQL on a raid 1, I would have pulled one of the drives, as a clone, therefore I could not have lost the setup. The raid 1 drive, still in the server, could have gone south due to the firmware flash, but I still would have had the pulled clone. With the clone, I could have been back in business in less then 20 minutes (that is including the background initialization when another disk was added to complete the mirror).

 

This is why I REFUSE to setup an important server without a separate raid 1 (or raid 10) for the OS.

 

If I read your question correctly, you simply want to know why this isn't an option to have pre-configured on your server at time of purchase.

 

Dell will not configure a RAID 0 for you because of the chance of loss of data.  If you want to set it up yourself, it is an option on all PERC controllers, although I do not recommend it.

 

I know the dollars are tight, but if you look at the cost of manhours spent reloading the OS array + loss of productivity, it will far excede the price of the additional drive required to make the OS array a RAID 1.

No, my question - which I obvioulsy didn't communicate correctly - is

 

if using RAID 10, is it possible to create logical drives within the array?  When RAID 10 is selected all drive space is used for one array, or VD, and can't be changed.

Just check to be sure I'm not missing something.  In the HP/Compaq setup, you create the array, then create volumes- hp terms them logical drives - The OS sees them as volumes.  the Perc 5 and below documentation I found is a little bit different than 6 - just wanted to be sure I wasn't missing something.

 

Thanks -

 

and I went ahead and ordered the 2nd drive for the OS.  :)

Logical drives are a function of the OS, Windows Disk Manager knows of them, raid adapters do not.

Once a raid 10 is created it can not be changed without destruction. 

 

There is a way to divide one array set into multiple volumes by not using all the space of a raid set to create an array volume, the remaining space becomes available to create more volumes,  but I have only seen this on a few servers in over 20 years, only done due to ignorance on the techs part. It can be dangerous in some instances, as I have seen a raid 1 and a raid 5 created from one array set, giving the false sense the OS was placed on a safer raid 1 array when in reality it no safer than the raid 5 it is married to.

 

"and I went ahead and ordered the 2nd drive for the OS. :smileyhappy: 

This way you won't have one of these .:smileysad:

 

 

"The OS sees them as volumes"

In Disk Manager, you will see the array volumes, just like a normal single drive, the "unallocated space is the unpartitioned volume, create one large or multiple smaller partitions. Once the partition(s) are created they format quickly, you can also create extended logical drives within the individual partitions...have not used those in years. Rarely do I need to create multiple partitions even on large arrays. With the newest array server I just got in, I have a raid 1 (approx 139 Gig) and a raid 5 (approx 400 Gig), I will likely just use one partition for each...multiple partitions do not speed up or slow down arrays, the mechanics of array storage are different then standard disks. Lastly. I generally give the arrays a volume label such as raid 1, Raid 5 etc, makes it easier for other techs walking in cold.

 

Thanks - I appreciate the help and encouragement to go with the RAID 1 now - I know the risk, just thought I was willing to take it. 

 

I appreciate the help and explanations.  I'm not new to drive management, just new to this Dell setup and wanted to make sure I wasn't missing something.

 

I know it happens, I know drives do go out, but in 10 years with Compaq I still have every scsi drive I've ever purchased.  I have a stack of about 8 9gb Ultra-scsi drives that aren't worth the space they take up (still I can't get rid of them - they cost better than 300)

 

Again- thanks!  I've read through this forum, it's been very helful to people.

Rather disappointed Lsilogic or Dell removed some of the configuration choices in the new raid bios setup;  some choices you need to run the array manager or use the CLI to set them.

I assume many users messed up the setup, like in creating a raid 01 instead of a raid 1, so it is now locked to protect the ignorant.

 

If I remember correctly, with the older raid adapters you were able to split a raid 10 container into multiple volumes within the bios setup.

I can see the point of dividing the container into multiple volumes within the raid setup, as it minimizes the loss of multiple partitions at one time due to a user screwup in Diskmanager, corruption or virus virus.

 

Not sure what is differnt on the Perc 6 setup, but the compaq setup seems to be more "logical".   This isn't a knock on Dell at all - but it is different enough that being used to it would make one wonder if something is missed.  In compaq disk manager setup - prior to os - you select phyiscal drives, create an array, then you have the option to create a drive and must enter the space allocated for that drive.  If you don't create the drive then you just have an array.

This Dell setup does this step automatically - as was posted you would have to change the disk space size number to allocate space for more than one logical drive.  Plus with the RAID 10 setup, not with other RAID selections but only with 10 the drive space field is locked, you can't change it to make the space used less and then create another logical drive.

 

It's not a big deal - of course you can create the logical drive in Windows disk manager, it's just different.