Boot from a Raid 5 Array

[NewNetworkAdmin]

Hi guys,

I'm fairly new to Solaris and have a question that will probably have simple yes or no answer...

Can you boot Solaris 9 from a Raid 5 Array set up with Solaris Management Console?

If so, what do I set the boot-device environment variable in Boot PROM to?

Thanks in advance

 

[cndcadams]

What type of system and array do you have and OS?

You will need to look at the following site;

http://www.adminschoice.com/docs/open_boot.htm

you can set all of this up from ok prompt;
or if you are interested in learning look into the eeprom command from OS level.
concentrate on nvedit, nvstore, and nvalias, use-nvramrc, boot-device?

you will also need to use
printenv to see settings from ok prompt or eeprom from OS;
setenv to set some settings from ok prompt or eeprom from OS;
devalias command will show pathing from low level.
when you set up your boot path devalias will show it.

from what I can remember not all system and array combo's are able to boot?

So make sure you let me know what you have?

CA

 

[NewNetworkAdmin]

CA,

We have a SunFire V250 with Solaris 9 installed. The Raid 5 Array was set up using the Solaris Management Console (therefore software Raid?)

If the Raid array has been set up in Solaris, will the open Boot know about the Raid volume before Solaris has started up. If not, then I guess it can't boot from the raid array. I prviously had our system drvies on a mirrored (Raid 1) set. To boot I just changed the boot-device proprty to "disk1 disk2". This works.

Thanks for your help

Andy

 

[cndcadams]

What model disk array do you have?
Or are these drives internal?


Thanks

CA

 

[cndcadams]

Here is something for you to look at. Helps set boot device
using the luxadm command.

Things to consider are your /etc/vfstab entries also.

How did you get the boot image on the raid 5(what was your basic procedure)?

 

[NewNetworkAdmin]

CA,
Our drives are internal.

cndcadams,
I haven't yet put the boot image onto the raid array. We currently have a mirror and want to upgrade it to Raid 5.

Andy

 

[cndcadams]

Ok I understand.

Probably the best way would be to remove all SVM and return to original boot drive configuration by breaking the mirror and unencapsulateing the boot drive.(follow the procedure on removeing SVM, it tells how to recover old /etc/vfstab and /etc/system etc. Then I would build svm raid 5 with boot device.

I think it will be important to get as many suggestions as possible before doing this.

Ideally you would have an identical system and try to create a procedure before doing it on this system if it is a production system.

For my own knowledge why is it that you want to use raid 5 for boot device? What will you gain?

CA

 

[NewNetworkAdmin]

CA,

Thanks for the info.

We need to have 2 separate DATA areas on our server (on different physical drives). Currently we have 2 mirrored disks containing our OS and 6 disks in a Raid 5 array. As I said, we want 2 data areas. The best way we calculated (by losing as little disk space as possible) is to Raid 5 three disks and use them as system drives (leaving plenty of space for 1 data area) and Raid 5 the other 5 disks leaving enough data space for the second data area.

Andy

 

[Willemvrm]

Andy,

I stil can not exactly understand why you want your boot disks on a raid 5?
If you want 2 data area's I would sugest:
- the 2 internal drives for a mirrored system disk
- 3 disks raid 5 for data area 1
- 3 disks raid 5 for data area 2
- or the 6 data disks raid 5 and that devided into two soft partitions

Also from the SVM Admin Guide (on docs.sun.com):
"However, you cannot use a RAID 5 volume for root (/), /usr, and swap, or for existing file systems.

 

[NewNetworkAdmin]

Willemvrm,

We wanted to have one RAID 5 array as big as possible, whilst still allowing data to be stored in a second area. 2 3 disk arrays would not provide enough space.

In the end we have opted for a different approach altogether...we have 2 mirrored drves for the system, 1 single drive for the first area (no raid at all) and the remaining 5 drives in a Raid 5 array. This just about gives us enough space.

Thanks for all your help guys.

Andy