Stuart, I'm simply curious - did you resolve your issue? What NAS (vendor/model/config) are you using?
On Fri, Jul 5, 2013 at 11:31 AM, Dennis Jenkins <dennis.jenkins...@gmail.com > wrote: > > On Fri, Jul 5, 2013 at 8:58 AM, Stuart Ford <stuart.f...@glide.uk.com>wrote: > >> On Fri, Jul 5, 2013 at 7:00 AM, Dennis Jenkins wrpte >> > > >> No. iSCSI traffic between the VMWare hosts and the SAN uses completely >> >> separate NICs and different switches to the "production" LAN. >> I've had a look at the task activity in VCEnter and found these two events >> > > >> at almost the same time as the kernel messages. In both cases the start >> time (the first time below) is 5-6 seconds after the kernel message, and >> I've seen that the clock on the Postgres VM and the VCenter server, at >> least, are in sync (it may not, of course, be the VCenter server's clock >> that these logs get the time from). >> >> Remove snapshot >> GLIBMPDB001_replica >> Completed >> GLIDE\Svc_vcenter >> 05/07/2013 11:58:41 >> 05/07/2013 11:58:41 >> 05/07/2013 11:59:03 >> >> Remove snapshot >> GLIBMPDB001_replica >> Completed >> GLIDE\Svc_vcenter >> 05/07/2013 10:11:10 >> 05/07/2013 10:11:10 >> 05/07/2013 10:11:23 >> >> > I would not blame Veeam. > > I suspect that when a snapshot is deleted that all iSCSI activity either > halts or slows SIGNIFICANTLY. This depends on your NAS. > > I've seen an Oracle 7320 ZFS Storage appliance, misconfigured to use > RAID-Z2 (raid6) to store terabytes of essentially random-access data pause > for minutes when deleting a snapshot containing a few dozen gigabytes. > (the snapshot deletion kernel threads get IO priority over "nfsd" file > IO). This causes enough latency to VMWare (over NFS), that VMWare gave up > on the IO and returned a generic SCSI error to the guests. Linux guests > will semi-panic and remount their file-systems read-only. FreeBSD will > just freak out, panic and reboot. The flaw here was using the wrong raid > type (since replaced with triple-parity raid-10 and is working great). > > What NAS are you using? > > How busy are its disks when deleting a snapshot? > > What is the RAID type under the hood? > >
