RAID levels, do you care about your data?

So I thought this was an interesting exchange on SpiceWorks.

Basically it questions the use of RAID 5 (or 50 in a production environment) this would apply whether you had an EqualLogic or any other SAN I would think?

Basically RAID 5 has a flaw called the

RAID-5 write hole. Whenever you update the data in a RAID stripe you must also update the parity, so that all disks XOR to zero — it’s that equation that allows you to reconstruct data when a disk fails. The problem is that there’s no way to update two or more disks atomically, so RAID stripes can become damaged during a crash or power outage.

I guess the question is, is it appropriate to have a production SQL or Exchange server running on a RAID 5 (or 50??) volume? Mr. Scott Alan Miller would I think say no. He likes RAID 10 for that sort of thing.

Any thoughts?


EqualLogic commandline magic

A couple of interesting EqualLogic commandline posts

Changing volume after volume in the GUI is painstaking and prone to errors. So in my opinion is scripting or command line the way to go. Since I needed him for a review for a document I quickly typed some commands for him. After connecting with SSH to the storage group this is all what you need to change a lot of volumes with some easy commands.

volume select <volumename>
create access username <chap account> ipaddress xx.xx.xx.xx apply-to volume authmethod chap

if you leave out the apply-to part, the rule will be applied to both the volume and the snapshot. If you have to change or add more

Since we use multiple VMKernel ports for iSCSI our commands looked like this:

volume select PROD01
create access username chappy ipaddress apply-to both authmethod chap
create access username chappy ipaddress apply-to both authmethod chap

volume select PROD02
create access username chappy ipaddress apply-to both authmethod chap
create access username chappy ipaddress apply-to both authmethod chap.

Now it only took about 5 minutes instead of an hour clicking and I got my document reviewed.


Do this before attaching lun’s to the host:

esxcli nmp satp setdefaultpsp –psp VMW_PSP_RR –satp VMW_SATP_EQL

It will put round robin as the default path policy to round robin, saves you lot of time

Infor Adage order line goes on CC_PENDCREDITCHECK and won’t go off

Gah this was caused by not having a Enterprise credit period for it to work with. To fix go to Extended Enterprise, Customer bill to ship to, Credit management, Enterprise Credit Periods, and then create it!

Setup AutoLogon to windows server 2008 in a domain

Create these registry values

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\DefaultUserName String %USERNAME&
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\DefaultPassword String %PASSWORD%
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\AutoAdminLogon DWORD 1

what to replace moen 12801 with, try Moen 1225

I also used some plumbers silicone grease.