On Wed, Feb 20, 2019 at 7:58 AM Robert Haas <robertmh...@gmail.com> wrote: > On Tue, Feb 19, 2019 at 1:56 PM Andres Freund <and...@anarazel.de> wrote: > > My point is that for iSCSC to be performant we'd need *all* the > > infrastructure we also need for direct IO *and* a *lot* more. And that > > it seems insane to invest very substantial resources into developing our > > own iSCSI client when we don't even have DIO support. And DIO support > > would allow us to address the error reporting issues, while also > > drastically improving performance in a lot of situations. And we'd not > > have to essentially develop our own filesystem etc. > > OK, got it. So, I'll merge the patch for direct I/O support tomorrow, > and then the iSCSI patch can go in on Thursday. OK? :-)
Not something I paid a lot of attention to as an application developer, but in a past life I have seen a lot of mission critical DB2 and Oracle systems running on ext4 or XFS over (kernel) iSCSI plugged into big monster filers, and also I think perhaps also cases of NFS, but those systems use DIO by default (and the latter has its own NFS client IIUC). So I suspect if you can just get DIO merged today we can probably skip the userland iSCSI and call it done. :-P -- Thomas Munro https://enterprisedb.com
