I think I was missing a key piece in that I thought that just doing a mmafmctl fs1 prefetch –j cache would start grabbing everything (data and metadata) but it appears that the –list-file myfiles.txt is the trigger for the prefetch to work properly. I mistakenly assumed that omitting the –list-file switch would prefetch all the data in the fileset.
From: <[email protected]> on behalf of Venkateswara R Puvvada <[email protected]> Reply-To: gpfsug main discussion list <[email protected]> Date: Thursday, April 6, 2017 at 5:45 AM To: gpfsug main discussion list <[email protected]> Subject: Re: [gpfsug-discuss] AFM misunderstanding Could you explain "bits of actual file" mentioned below ? Prefetch with –metadata-onlypulls everything (xattrs, ACLs etc..) except data. Doing "ls –ltrs" shows file allocation size as zero if data prefetch not yet completed on them. ~Venkat ([email protected]) From: Mark Bush <[email protected]> To: gpfsug main discussion list <[email protected]> Date: 04/06/2017 07:24 AM Subject: [gpfsug-discuss] AFM misunderstanding Sent by: [email protected] ________________________________ When I setup a AFM relationship (let’s just say I’m doing RO), does prefetch bring bits of the actual file over to the cache or is it only ever metadata? I know there is a –metadata-only switch but it appears that if I try a mmafmctl prefetch operation and then I do a ls –ltrs on the cache it’s still 0 bytes. I do see the queue increasing when I do a mmafmctl getstate. I realize that the data truly only flows once the file is requested (I just do a dd if=mycachedfile of=/dev/null). But this is just my test env. How to I get the bits to flow before I request them assuming that I will at some point need them? Or do I just misunderstand AFM altogether? I’m more used to mirroring so maybe that’s my frame of reference and it’s not the AFM architecture. Mark This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. This message may be viewed by parties at Sirius Computer Solutions other than those named in the message header. This message does not contain an official representation of Sirius Computer Solutions. If you have received this communication in error, notify Sirius Computer Solutions immediately and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication. Thank you. Sirius Computer Solutions<http://www.siriuscom.com/> _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
_______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
