Good idea! I setup a RAM disk on both of those systems, let them sync, added it
to the cluster.
One thing I left out (which didn't hit me until yesterday as a possibility) is
that I have the iSCSI LUN attached to two Windows servers that are acting as a
Scale-Out File Server. When I copied a file over to the new RAMdisk LUN via
Scale-Out File Server, I am still getting 10-20MB/s; however, when I create a
large file to the underlying, shared DRBD on those CentOS machines, I am
getting about 700+MB/s, which I watched via iostat. So, I guess it's the
Scale-Out File Server causing the issue. Not sure why Microsoft and the
Scale-Out File Server is causing the issue - guess Microsoft really doesn't
like non-Microsoft backing disks
Does anyone have any experience with that, perhaps? Thanks!!
Respectfully,
Tyler
Nov 14, 2022, 2:30 AM by ulrich.wi...@rz.uni-regensburg.de:
> Hi!
>
> If you have planty of RAM you could configure an iSCSI disk using a ram disk
> and try how much I/O you get from there.
> Maybe you issue is not-su-much DRBD related. However when my local MD-RAID1
> resyncs with about 120MB/s (spinning disks), the system also is hardly usable.
>
> Regards,
> Ulrich
>
>>>> Tyler Phillippe via Users <users@clusterlabs.org> schrieb am 13.11.2022 um
>>>>
> 19:26 in Nachricht <ngme_x7--...@tutamail.com>:
>
>> Hello all,
>>
>> I have setup a Linux cluster on 2x CentOS 8 Stream machines - it has
>> resources to manage a dual primary, GFS2 DRBD setup. DRBD and the cluster
>> have a diskless witness. Everything works fine - I have the dual primary
>> DRBD
>> working and it is able to present an iSCSI LUN out to my LAN. However, the
>> DRBD write speed is terrible. The backing DRBD disks (HDD) are RAID10 using
>> mdadm and they (re)sync at around 150MB/s. DRBD verify has been limited to
>> 100MB/s, but left untethered, it will get to around 140MB/s. If I write data
>> to the iSCSI LUN, I only get about 10-15MB/s. Here's the DRBD
>> global_common.conf - these are exactly the same on both machines:
>>
>> global {
>> usage-count no;
>> udev-always-use-vnr;
>> }
>>
>> common {
>> handlers {
>> }
>>
>> startup {
>> wfc-timeout 5;
>> degr-wfc-timeout 5;
>> }
>>
>> options {
>> auto-promote yes;
>> quorum 1;
>> on-no-data-accessible suspend-io;
>> on-no-quorum suspend-io;
>> }
>>
>> disk {
>> al-extents 4096;
>> al-updates yes;
>> no-disk-barrier;
>> disk-flushes;
>> on-io-error detach;
>> c-plan-ahead 0;
>> resync-rate 100M;
>> }
>>
>> net {
>> protocol C;
>> allow-two-primaries yes;
>> cram-hmac-alg "sha256";
>> csums-alg "sha256";
>> verify-alg "sha256";
>> shared-secret "secret123";
>> max-buffers 36864;
>> rcvbuf-size 5242880;
>> sndbuf-size 5242880;
>> }
>> }
>>
>> Respectfully,
>> Tyler
>>
>
>
>
>
> _______________________________________________
> Manage your subscription:
> https://lists.clusterlabs.org/mailman/listinfo/users
>
> ClusterLabs home: https://www.clusterlabs.org/
>
_______________________________________________
Manage your subscription:
https://lists.clusterlabs.org/mailman/listinfo/users
ClusterLabs home: https://www.clusterlabs.org/
