Dell - Internal Use - Confidential If you disable multipathd and test against a single path, do you see the same latency?
I'm wondering if there is a Networking issue at play. -----Original Message----- From: linux-poweredge-bounces-Lists On Behalf Of Chris Adams Sent: Thursday, April 13, 2017 1:24 PM To: linux-poweredge-Lists <[email protected]> Subject: [Linux-PowerEdge] EqualLogic, Linux, and latency I have a stack of PowerEdge servers, running CentOS 7 and oVirt (virtualization environment), using an EqualLogic PS6610 for VM storage. I'm using the regular Linux multipath daemon, not the Dell kit, because oVirt manages the multipathing (and doesn't handle the Dell kit). I am periodically seeing high latency from the SAN, even from a host not running any VMs. I see 100+ ms reads, and sometimes even multi-second reads (to read a single 4K block). oVirt logs warnings about this; I wrote a simple perl script that duplicates what oVirt does (open a metadata logical volume block device with O_DIRECT, read a 4K block, and close it), and I see the same thing. I've got iscsid and multipathd configured per the recommended values, and I'm not seeing any issues on Linux or at the switches (dedicated network for iSCSI); it would seem to be something on the SAN itself. The SAN isn't reporting anything though, so I'm not sure what to look at. Any suggestions? -- Chris Adams <[email protected]> _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge
