[DRBD-user] Slow DRBD since Kernel 5 (PVE Kernel)

Gianni Milo gianni.milo22 at gmail.com
Fri Jul 26 11:50:34 CEST 2019


Hi Alexander,

Do you get same behaviour when using other tools like iperf for example ?
if so, then this might be not related to the DRBD itself, but due to
ethernet drivers issues for example..

Gianni




On Thu, 25 Jul 2019 at 13:26, Alexander Karamanlidis <
alexander.karamanlidis at lindenbaum.eu> wrote:

> Hi everyone,
>
>
> so we upgraded to PVE6 (Proxmox VE 6) about a week ago to test it.
>
> Since then our DRBD resource got incredibly slow (Around 105Mbit/s).
>
> If we boot to Kernel 4.15 our Speeds get back to normal (Max 15Gbit/s)
>
>
> Here's some data:
>
>
> root at node1:~# cat
> /sys/kernel/debug/drbd/resources/r0/connections/node2/0/proc_drbd ; echo
> -e "\n\n" ; uname -a ; echo -e "\n\n" ; dpkg -l | grep
> 'pve-kernel\|drbd' ; echo -e "\n\n" ; drbdadm dump
>  0: cs:SyncTarget ro:Secondary/Primary ds:Inconsistent/UpToDate C r-----
>     ns:0 nr:12242948 dw:12242948 dr:110085144 al:0 bm:0 lo:0 pe:[0;93]
> ua:0 ap:[0;0] ep:1 wo:2 oos:7352525548
>         [>....................] sync'ed:  1.5% (7180200/7287584)M
>         finish: 4:03:52 speed: 502,476 (530,020 -- 484,408) want:
> 2,000,000 K/sec
>           1% sector pos: 297469952/15002273264
>         resync: used:2/61 hits:214057 misses:1684 starving:0 locked:0
> changed:842
>         act_log: used:0/1237 hits:0 misses:0 starving:0 locked:0 changed:0
>         blocked on activity log: 0/0/0
>
>
>
> Linux node1 4.15.18-18-pve #1 SMP PVE 4.15.18-44 (Wed, 03 Jul 2019
> 11:19:13 +0200) x86_64 GNU/Linux
>
>
>
> ii  drbd-dkms                            9.0.19-1
> all          RAID 1 over TCP/IP for Linux module source
> ii  drbd-utils                           9.10.0-1
> amd64        RAID 1 over TCP/IP for Linux (user utilities)
> ii  drbdtop                              0.2.1-1
> amd64        like top, but for drbd
> ii  pve-firmware                         3.0-2
> all          Binary firmware code for the pve-kernel
> ii  pve-kernel-4.15                      5.4-6
> all          Latest Proxmox VE Kernel Image
> ii  pve-kernel-4.15.18-12-pve            4.15.18-36
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-4.15.18-16-pve            4.15.18-41
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-4.15.18-18-pve            4.15.18-44
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-5.0                       6.0-5
> all          Latest Proxmox VE Kernel Image
> ii  pve-kernel-5.0.15-1-pve              5.0.15-1
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-helper                    6.0-5
> all          Function for various kernel maintenance tasks.
>
>
>
> # /etc/drbd.conf
> # resource r0 on node1: not ignored, not stacked
> # defined at /etc/drbd.d/r0.res:1
> resource r0 {
>     on node1 {
>         node-id 1;
>         volume 0 {
>             device       /dev/drbd0 minor 0;
>             disk
> /dev/disk/by-uuid/8a879a82-3880-4998-b5cb-70a95ce4bf79;
>             meta-disk    internal;
>         }
>         address          ipv4 192.168.99.1:7788;
>     }
>     on node2 {
>         node-id 0;
>         volume 0 {
>             device       /dev/drbd0 minor 0;
>             disk
> /dev/disk/by-uuid/8a879a82-3880-4998-b5cb-70a95ce4bf79;
>             meta-disk    internal;
>         }
>         address          ipv4 192.168.99.2:7788;
>     }
>     net {
>         after-sb-0pri    discard-zero-changes;
>         after-sb-1pri    discard-secondary;
>         after-sb-2pri    disconnect;
>         csums-alg        sha1;
>         max-buffers      36864;
>         max-epoch-size   20000;
>         rcvbuf-size      2097152;
>         sndbuf-size      1048576;
>         verify-alg       sha1;
>     }
>     disk {
>         c-fill-target    10240;
>         c-max-rate       2237280;
>         c-min-rate       204800;
>         c-plan-ahead       0;
>         resync-rate      2000000;
>     }
> }
>
>
>
> If we put I/O on the DRBD Resource we get a maximum of 14.19Gbit/s (We
> have 25Gbit/s direct Attached Network) on our bond interface with the
> 4.15 Kernel
>
>
>
>
>
>
> root at node1:~# cat
> /sys/kernel/debug/drbd/resources/r0/connections/node2/0/proc_drbd ; echo
> -e "\n\n" ; uname -a ; echo -e "\n\n" ; dpkg -l | grep
> 'pve-kernel\|drbd' ; echo -e "\n\n" ; drbdadm dump
>  0: cs:SyncTarget ro:Secondary/Primary ds:Inconsistent/UpToDate C r-----
>     ns:0 nr:541700 dw:541700 dr:10270724 al:0 bm:0 lo:0 pe:[0;107] ua:0
> ap:[0;0] ep:1 wo:2 oos:7334758124
>         [>....................] sync'ed:  0.2% (7162848/7172768)M
>         finish: 14:05:20 speed: 144,596 (154,112 -- 166,556) want:
> 2,000,000 K/sec
>           2% sector pos: 332978176/15002273264
>         resync: used:2/61 hits:19875 misses:162 starving:0 locked:0
> changed:81
>         act_log: used:0/1237 hits:0 misses:0 starving:0 locked:0 changed:0
>         blocked on activity log: 0/0/0
>
>
>
> Linux node1 5.0.15-1-pve #1 SMP PVE 5.0.15-1 (Wed, 03 Jul 2019 10:51:57
> +0200) x86_64 GNU/Linux
>
>
>
> ii  drbd-dkms                            9.0.19-1
> all          RAID 1 over TCP/IP for Linux module source
> ii  drbd-utils                           9.10.0-1
> amd64        RAID 1 over TCP/IP for Linux (user utilities)
> ii  drbdtop                              0.2.1-1
> amd64        like top, but for drbd
> ii  pve-firmware                         3.0-2
> all          Binary firmware code for the pve-kernel
> ii  pve-kernel-4.15                      5.4-6
> all          Latest Proxmox VE Kernel Image
> ii  pve-kernel-4.15.18-12-pve            4.15.18-36
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-4.15.18-16-pve            4.15.18-41
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-4.15.18-18-pve            4.15.18-44
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-5.0                       6.0-5
> all          Latest Proxmox VE Kernel Image
> ii  pve-kernel-5.0.15-1-pve              5.0.15-1
> amd64        The Proxmox PVE Kernel Image
> ii  pve-kernel-helper                    6.0-5
> all          Function for various kernel maintenance tasks.
>
>
>
> # /etc/drbd.conf
> # resource r0 on node1: not ignored, not stacked
> # defined at /etc/drbd.d/r0.res:1
> resource r0 {
>     on node1 {
>         node-id 1;
>         volume 0 {
>             device       /dev/drbd0 minor 0;
>             disk
> /dev/disk/by-uuid/8a879a82-3880-4998-b5cb-70a95ce4bf79;
>             meta-disk    internal;
>         }
>         address          ipv4 192.168.99.1:7788;
>     }
>     on node2 {
>         node-id 0;
>         volume 0 {
>             device       /dev/drbd0 minor 0;
>             disk
> /dev/disk/by-uuid/8a879a82-3880-4998-b5cb-70a95ce4bf79;
>             meta-disk    internal;
>         }
>         address          ipv4 192.168.99.2:7788;
>     }
>     net {
>         after-sb-0pri    discard-zero-changes;
>         after-sb-1pri    discard-secondary;
>         after-sb-2pri    disconnect;
>         csums-alg        sha1;
>         max-buffers      36864;
>         max-epoch-size   20000;
>         rcvbuf-size      2097152;
>         sndbuf-size      1048576;
>         verify-alg       sha1;
>     }
>     disk {
>         c-fill-target    10240;
>         c-max-rate       2237280;
>         c-min-rate       204800;
>         c-plan-ahead       0;
>         resync-rate      2000000;
>     }
> }
>
> If we put I/O on the DRBD Resource we get a maximum of 107Mbit/s (We
> have 25Gbit/s direct Attached Network) on our bond interface with the
> 5.0.15 Kernel
>
>
>
> Maybe someone has a clue what changed in Kernel 5 that is slowing us
> that much down.
>
> Maybe someone even knows a solution for that.
>
>
>
> Kind Regards,
>
> Alexander Karamanlidis
>
>
>
>
>
> _______________________________________________
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