How To
Summary
In this article we discuss the SAN boot of the operating systems as normal and removing the need for slow and lower reliability of internal disks.
Objective
Steps
Internal disks on a E870/880/E980? - "you having a laugh! "
- Are you mad?
- Are you a Luddite?
- Is the date 1995 in your country?
Three Reasons:
- VERY slow (200 I/O per second) compared to a caching SAN disk unit with dozens of disks or even a Flash SAN unit at hundreds of times faster. Why would you want your VIOS to be that slow at disk I/O?
- MUCH lower RAS than a SAN disks (single brown spinning disks are single points of failure and mechanical disks the most likely thing to break in your computer). In my small computer room, I have replaced four duff hard disks in the past 2 years - all internal brown spinning drives in VIOS and its a real mess compared to replacing a RAID5 disk of a SAN disk unit. Actually not wanting to defeat my own argument, I enjoyed rolling up my sleeves and hacking away in AIX to try to convince it that the disk is dead and to remove it. A real blast from the past. After nine years a few of the disks in my four V7000s have failed but it is a very task of replacing as I have space disks and RAID5 and the V7000 does all the hard work and rebuild automatically.
- VERY expensive (due to ESP24 and/or extra I/O Expansion Drawers and/or adapters). All those components add up to very high costs per GB for slower and lower RAS devices - just don't do it.The only feeble excuse for having internal disks is so you can boot an OS (VIOS) to investigate the SAN and prove it is the SAN teams fault. But you can do that with S812 or S922 at fraction of the price. These days the SAN team rarely make large mistakes and know fully when the SAN is down. If the SAN is down then 99.9% of the enterprise computer room is already dead.
SAN boot is so obvious - it is a given default now.
- With POWER6 SAN boot was a little new and only for the brave/confident.
- With POWER7 it was a 50:50 choice - I regret opting for internal disks on my machines!
- With POWER8 it is SAN boot all the way.
- And POWER9, it is 100% normal for SAN Flash disks and old fashioned brown spinning things used for archive only.
The same goes for the E850 and E950 - even with the reduced cost of internal drives the other two factors still make SAN boot a better choice - with the assumption you already have a SAN disk subsystem and professional SAN team.
RAS = Reliability (higher quality parts are less likely to break), Availability (if one component breaks the server stays up, running and working) and Serviceability ( the part can be replaced with the server running = no outage)
Next you will be asking (I am joking here):
- Floppy disk or USB Memory drive - which is best?
- Will Ethernet take over from Token Ring?
- Is there a case for moving on from ferrite magnetic core memory?
I hope this helps. As always I would like to hear your opinions and horror stories via the comments below.
Additional Information
Other places to find content from Nigel Griffiths IBM (retired)
- YouTube - YouTube Channel for Nigel Griffiths
- AIXpert Blog
Document Location
Worldwide
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"HW1W1","label":"Power -\u003EPowerLinux"},"Component":"","Platform":[{"code":"PF016","label":"Linux"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"","label":""}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG60","label":"IBM i"},"Component":"","Platform":[{"code":"PF012","label":"IBM i"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB57","label":"Power"}}]
Was this topic helpful?
Document Information
Modified date:
14 June 2023
UID
ibm11116195