Hi everyone, we've been tracing an issue where snapshot replication is causing interruptions for the NFS serivce.
The problem is as follows: Every time a zfs recv finishes, there is a chance for the NFS server to return an NFSERR_IO for a GETATTR call. This shows up as input/output errors on the nfs clients. Here the tcpdump showing the NFS conversation: https://nopaste.me/view/95d1a79d NFS 202 V3 GETATTR Call (Reply In 6043), FH: 0x8c711a60 NFS 98 V3 GETATTR Reply (Call In 6042) Error: NFS3ERR_IO NFS 222 V3 LOOKUP Call (Reply In 6046), DH: 0x6694634f/example.file.txt NFS 102 V3 LOOKUP Reply (Call In 6045) Error: NFS3ERR_ACCES We've been able to verify that there is a _direct_ correlation between the zfs recv command and these NFS errors. For every input/output error we can find a log entry of a replication just finishing (zfs recv exiting). The receiving server is running 10.3-RELEASE I've read about a VFS/ZFS deadlock issue which is to be included/fixed in Freebsd 11.0-BETA4. Could our issue be related? Otherwise does anyone have any suggestions how to tackle this issue? For the record, say we have two volumes: tank/volumeA and tank/volumeB If there is a zfs recv busy for tank/volumeA then tank/volumeB can get these NFS "io" errors, it does not have to be the same volume. Has anyone else seen/experience this as well? Any insights are appreciated! With kind regards, Daniel _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
