Hello everyone. I found a lot of very useful information here but this time I have some doubts so I decided to subscribe and ask.
Recently we upgraded our hardware (z9 + DS6000 -> z114 + DS6000 + XIV) and we have to make some choices. There is a chance that at some point we will have to get rid of DS6000 and we will have to store store everything on XIV. I know that it is not best choice for z/vm but DS is a pretty old guy and maintaining it may become expensive. But anyway, to the point. I am building linux guests under z/vm (right now 5.4 but it will change soon). Data disks for oracle I will build using direct attached FCP/SCSI. It is pretty easy to manage, multipathing is working fine - no doubts over here. But what about linux system disks? I know that in general ECKD win over FCP. But does FCP win over EDEV when we are talking about linux system? I've already encountered some problems with direct attached FCP/SCSI. Main one is multipathing when you want to use a clone/snapshot. WWID for scsi device changes and multipathing brakes. I can work around this but who knows If I am gonna be able to do this in 1 year from know, under time pressure when something happens. In case like this I have to boot a clone without multipathing (option multipath=off in zipl), update fstab, zipl with new wwid , reboot few times etc, boot updated guest with multipath. A little dirty but works. Now I am looking into EDEV. I know it can impact performance but it is 'just' a system drive. We don't need a lot of iops here right? So the question is : should I stick to FCP/SCSI as much as possible or just go with EDEV for my linux system disks (and put oracle on FCP direct attached). And I also would like to ask - what is difference between attributes "XIV" and "SCSI" in "EDEVICE" statement? Both are scsci over fiber so why there is an extra one for XIV? Thanks! Grzegorz Powiedziuk ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
