Depending on the size of your shop, but money is a consideration in smaller shops.
i.e. You already have ficon attached dasd with twin ficon cards. Now you need another pair of FCP cards (at how much per card), and FCP attached dasd (lparing your current DS6800 orr DS8000, or a separate dasd subsystem) and, what do you get? Slightly better performance (is the performance increase worth the cost?). Another set of underutilized channels (depending on the size of your shop and requirements) DASD that can't be universally used (some OS and older releases may not support FCP attached dasd) What else can you do with the money? Then, the other things that have already been mentioned, like lack of good performance monitors and detail compared to standard dasd subsystems. I assume that the SANs have their version of flashcopy and mirroring. In other words, if you need the performance, go for it. If you don't need the performance, then I'm not sure I would step up to it. In my setup, two years ago, we upgraded to an IBM z/890 with IBM DS6800. LPARing the DS6800 to a FCP side was a possibility. I rejected it due to the cost and little perceived benefit. Today, I would make the same decision here. However, at the next processor/dasd upgrade point, I would revisit the decision. But my gut feeling of our performance needs in the next two years, would steer me away from adding FCP, at this time. But, if the Open Systems group, wanted to replace their current SANs and I was offered additional disk space on it, I would consider adding the FCP ability instead of an upgrade to the DS6800. Just depends on how the cost numbers work out. <G> End of ramble... The cost of supporting two different DASD subsystems (ficon and fcp) is a cost that has to be considered vs the cost of supporting a single, slightly lower performance ficon DASD Subsystem. Tom Duerbusch THD Consulting >>> "Lionel B. Dyck" <[EMAIL PROTECTED]> 3/26/2007 11:09 AM >>> I've heard several good reasons to have my zlinux images use dasd that is on the fibre connected san and a few for using the old tried and true dasd. What I'd like to find out is what is true and what isn't - basically what is considered the best practice for zlinux dasd. Thus - what do y'all think? Thanks in advance. Lionel B. Dyck, Consultant/Specialist zLinux Platform Client and Platform Engineering Services (CAPES) KP-IT Enterprise Engineering, Manager Toni Nicotera 925-926-5332 (8-473-5332) | E-Mail: [EMAIL PROTECTED] AIM: lbdyck | Yahoo IM: lbdyck Kaiser Service Credo: "Our cause is health. Our passion is service. We*re here to make lives better.* *Never attribute to malice what can be caused by miscommunication.* NOTICE TO RECIPIENT: If you are not the intended recipient of this e-mail, you are prohibited from sharing, copying, or otherwise using or disclosing its contents. If you have received this e-mail in error, please notify the sender immediately by reply e-mail and permanently delete this e-mail and any attachments without reading, forwarding or saving them. Thank you. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
