Upgrading RAID 5 with a new disk using ML350.

[Pedro Silva_5]

Hello,

I'm quite a newbie in matters concerning servers and i've got to insert a new disk into the ML350 server using RAID 5.

It has 3 disks: 18.2 GB 10K Ultra SCSI and we need a new one with 36GB.

Considering this i've got two major doubts:

1) What kind of disks are compatible with the 18GB 10K Ultra SCSI to use with RAID5.

2) Is it possible to have a bigger disk in the RAID5 (ex: adding 36GB disk to a combination of 3 18GB)

Thanks in advance.

Pedro Silva

[JohnWRuffo]

Pedro:

Yes, you can install this disk and use it to expand the existing array. But, you will loose 18GB of space. The larger disk will only show up as an extra 18GB once it is added to the capacity of the RAID5.

If you need an extra 36GB of space on your array, you would need to add another disk to the array. Alternatively, if you need a total of 36GB of space in a RAID configuration, you could add two 36GB drives in a RAID1 (mirror) and achive the needed space.

You could also add the new 36GB drive as a RAID0 (or JBOD) and get the needed space, but without the redundancy of a true RAID array.

Here are some documents that may help explain some of the alternatives described:

RAID Drive Replacement:
ftp://ftp.compaq.com/pub/products/servers/proliantstorage/drives-enclosures/hp%20hard%20drive%20replacement.pdf

Advantages of RAID ADG, RAID5 or RAID1+0
ftp://ftp.compaq.com/pub/products/servers/proliantstorage/arraycontrollers/Assessing_ADG_v_5_v_1+0.pdf

Expanding Arrays in Windows 2000:
ftp://ftp.compaq.com/pub/products/servers/proliantstorage/drives-enclosures/Procedures%20of%20expanding%20active%20volume%20with%20W2000.pdf

Array Configuration Utility Users Guide:
ftp://ftp.compaq.com/pub/supportinformation/techpubs/user_reference_guides/239449-004_rev4_us.pdf

I hope that this reading material helps you in your planning. -john

[Pedro Silva_5]

Ok, thanks John, now i can see the picture about the array configuration.

Now my only remaining doubt is about the drives compatibility:

Considering that the existing drives are 10K Ultra SCSI can the new drive be a 15K or U320?

Thanks.

[JohnWRuffo]

Pedro:

The drives will be connected to a SmartArray Controller that will manage the drives. Different speeds or even protocol will not hinder you from using this drive; the new drive is backwards compatible.

Here is something else to read:
ftp://ftp.compaq.com/pub/products/servers/proliantstorage/drives-enclosures/hd-substitution.pdf

ftp://ftp.compaq.com/pub/products/servers/proliantstorage/drives-enclosures/whybuy-server-hd.pdf

[Pedro Silva_5]

John,

Thank you. You've been a great help.

Let's hope i'm up to the upgrade and RAID 5 installation.

Thanks.

[JohnWRuffo]

Follow the steps in the Array Configuration Utility User Guide. It is key stroke tested and fairly well written.
G'luck!