Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi,
I'm facing extremely slow DRBD sync (inital and re-sync) on my home lab setup.
I've tried many tuning parameters but nothing seems to really improve performances.
Moreover, in my Primary/Primary setup I'm also having some split-brains under certains circumstances.
Setup :
2 HP Proliant Microservers GEN 8 :
pcsrv01 :
CPU : Intel(R) Xeon(R) CPU E3-1220L V2 @ 2.30GHz : 2 cores / 4 threads
RAM : 16GB ECC
Disk : 1 SSD Crucial CT250MX200SSD1
pcsrv02 :
CPU : Intel(R) Celeron(R) CPU G1610T @ 2.30GHz
RAM : 16GB ECC
Disk : 1 SSD Kingston SUV400S37240G
Disks :
On the SSD, only one partition is created and DRBD is using it directly.
System is installed on a MicroSD directly on the mobo of the server.
# fdisk -l /dev/sda
Disk /dev/sda: 223.6 GiB, 240057409536 bytes, 468862128 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x503aad21
Device Boot Start End Sectors Size Id Type
/dev/sda1 2048 461375487 461373440 220G 8e Linux LVM
Network :
Both servers have 2 gigabit interfaces
One for access to network
One dedicated to DRBD sync with a MTU of 9000 <= direct
link between interfaces, no switch
Configuration :
r0.res :
resource r0 {
startup {
become-primary-on both;
}
net {
protocol C;
allow-two-primaries;
sndbuf-size 0;
max-buffers 8000;
max-epoch-size 8000;
sndbuf-size 512k;
rcvbuf-size 1024k;
}
on pcsrv01 {
device /dev/drbd0;
disk /dev/sda1;
address 192.168.1.10:7788;
meta-disk internal;
}
on pcsrv02 {
device /dev/drbd0;
disk /dev/sda1;
address 192.168.1.11:7788;
meta-disk internal;
}
disk {
on-io-error detach;
c-plan-ahead 0;
c-fill-target 24M;
c-min-rate 33M;
c-max-rate 110M;
}
}
1. With this setup, I'm facing horrible performances during syncing :
# cat /proc/drbd
version: 8.4.7 (api:1/proto:86-101)
srcversion: 2DCC561E7F1E3D63526E90D
0: cs:SyncSource ro:Primary/Primary ds:UpToDate/Inconsistent C r---b-
ns:5504329 nr:480 dw:5112648 dr:4092323 al:654 bm:0 lo:244 pe:132 ua:12 ap:234 ep:1 wo:f oos:222119720
[>....................] sync'ed: 1.2% (216912/219472)M
finish: 2:16:11 speed: 27,160 (1,824) K/sec
What can I do to improve that ?
2. On top of DRBD disk, I've created a physical volume used in Primary/Primary VG (shared between 2 Proxmox instances). When I'm creating a LV (and it's FS) on the remote note, I'm facing split brain due to this error :
block drbd0: Remote failed to finish a request within 42008ms > ko-count (7) * timeout (60 * 0.1s)
I've performed a full smartctl test and a full badblocks (in write mode) on my disks and no problems have been noticed.
Do you have some suggestions for me ?
Many thanks.
--
\o/ Sent from my tty \o/