Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Sun, Jun 16, 2013 at 6:44 AM, cesar <brain at click.com.py> wrote: > Right digimar, Red Hat did the fence software. > > Only for comment, please see this link of Red Hat, and you will see that > "fence_ack_manual" is supported: > https://access.redhat.com/site/articles/27136 > In my opinion "fence_ack_manual" is supported to escape from situations where the fencing mechanism is not working as expected e.g. (from the article you just cited) "*site-to-site link failure would prevent fencing from working between the sites"* So as Digimar already told: *you need fencing*!! I think it is the last time some one tell you: *you need fencing*!! > And about DRBD over a direct connection in mode round robin, can you give > me > links or comments about this case? (This is very important for me because I > will lose connection speed if I change of balance-rr to active-backup). > https://www.kernel.org/doc/Documentation/networking/bonding.txt balance-rr: This mode is the only mode that will permit a single TCP/IP connection to stripe traffic across multiple interfaces. It is therefore the only mode that will allow a single TCP/IP stream to utilize more than one interface's worth of throughput. This comes at a cost, however: the striping generally results in peer systems receiving packets out of order, causing TCP/IP's congestion control system to kick in, often by retransmitting segments. The problem is you have out of order packets and it doesn't help if you start to play around with net.ipv4.tcp_reordering sysctl parameter because there will always be a chance to have out of order packets. Ordered packets are indeed fundamental to DRBD. In DRBD world the bonding driver is used to achieve HA using active/backup or 802.3ad. Neither of which will boost your performance (802.3ad can improve performance if and only if you have a great number of TCP connections but that's not the case with your DRBD scenario). In either case, I am grateful to you for your kind attention, your time and > your information. > > Best regards > Cesar I *think* balance-rr bonding mode (and out of order packets) could be the source of your specific problem: Jun 14 08:50:12 kvm5 kernel: block drbd0: Digest mismatch, buffer modified by upper layers during write: 21158352s +4096 Jun 14 08:50:12 kvm6 kernel: block drbd0: Digest integrity check FAILED: 21158352s +4096 So just try to go active/backup bonding mode and let's see what happens but please do remember: You need fancing! Cheers, Luca -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20130616/6021471a/attachment.htm>