Paging spaces on ESS?

[swortsoul]

AIX recommends not to put any paging spaces on ESS disks. Why is that exactly? On a couple machines I just inherited, there are secondary paging spaces on the ESS. The software vendor is telling us we must move them to internal disks (which we don't have), 2 weeks before a major deadline. They say the machine won't boot if we lose the ESS. I thought it would boot as long as the primary paging space is on the internal scsi disks. I trust IBM more than this vendor, so we will try to get another internal disk and move the secondary paging space to it, but I'd like to know why IBM suggests this.

Thanks
Tim

 

[swortsoul]

Sorry, I didn't search the forum for this first. I saw some posts about IBM not supporting it. Is this still the case?

On our site, we currently have 2 secondary paging spaces on ESS disks. Why should we move them off?

1. IBM doesn't support it. Is this still the case?
2. Internal better performance. I doubt this since the ESS has fiber connections and internal are scsi.
3. Machine won't boot without ESS. I didn't think this was the case since the primary paging space is internal.

Thanks
Tim

 

[bi]

According to a RedBook, while the system is booting only the primary paging space (hd6) is active.

One way you could test whether it would boot without the ESS disks is to either turn the ESS disks off or disconnect the cables to the ESS and boot the system. You'll get a bunch of errors because the filesystems on the ESS that the system wants to mount won't be available, but you might be able to prove or disprove that the system can boot.

 

[Yegolev]

i know the system will boot without non-primary paging. in fact i have booted a machine or three with an inactive hd6. they do not support such things because "cables are the customer's responsibility" in IBM's terms. naturally, if your machine has some connectivity problems to paging and the system gets borked, they don't want to have to deal with that.

we use EMC frames on fibre, and even we don't like putting paging external. you never know when someone will drop a floor tile on a cable.

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