[DRBD-user] drbd storage size

Cesar Peschiera brain at click.com.py
Sat Oct 25 13:38:05 CEST 2014

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


Hi Meji

In three weeks i will have two Intel NIC X520-QDA1 of 40 Gb/s, according to 
these link:
http://ark.intel.com/products/68672/Intel-Ethernet-Converged-Network-Adapter-X520-QDA1
http://www.intel.com/content/www/us/en/network-adapters/converged-network-adapters/ethernet-x520-qda1-brief.html

In my Hardware setup also i have a RAID controller H710p of Dell (LSI 
chipset with 1 MB of cache) and with two groups of 4 HDDs SAS 15K RPM,  each 
group is  configured in RAID 10, this setup is applied for each Server (the 
HDDs for the OS are in other RAID), obviously i don't have much storage 
compared to yours.

In these Servers i will have running DRBD 8.4.5 version

If you want to know the result of my tests, only let me know.

Best regards
Cesar

----- Original Message ----- 
From: "Meij, Henk" <hmeij at wesleyan.edu>
To: <drbd-user at lists.linbit.com>
Sent: Thursday, October 23, 2014 5:10 PM
Subject: Re: [DRBD-user] drbd storage size


> a) it turns out the counter  (8847740/11287100)M goes down, not up, deh, 
> never noticed
>
> b) ran plain  rsync across eth0 (public, with switches/routers) and eth1 
> (nic to nic)
> eth0 sent 585260755954 bytes  received 10367 bytes  116690412.98 bytes/sec
> eth1 sent 585260755954 bytes  received 10367 bytes  122580535.41 bytes/sec
> so my LSI raid card is behaving and DRBD is slowing the initialization 
> down somehow.
> Found chapter 15 and will try some suggestions but ideas welcome.
>
> c) for grins
> version: 8.4.5 (api:1/proto:86-101)
> GIT-hash: 1d360bde0e095d495786eaeb2a1ac76888e4db96 build by 
> mockbuild at Build64R6, 2014-08-17 19:26:04
> 0: cs:SyncTarget ro:Secondary/Secondary ds:Inconsistent/UpToDate C r-----
>    ns:0 nr:3601728 dw:3601408 dr:0 al:0 bm:0 lo:4 pe:11 ua:3 ap:0 ep:1 
> wo:f oos:109374215324
>        [>....................] sync'ed:  0.1% (106810756/106814272)M
>        finish: 731:23:05 speed: 41,532 (31,868) want: 41,000 K/sec
>
> 100TB in 731 hours would  be 30 days. Can I expect large delta data 
> replication to go equally slow using DRDB?
>
> -Henk
>
>
>
> ________________________________________
> From: drbd-user-bounces at lists.linbit.com 
> [drbd-user-bounces at lists.linbit.com] on behalf of Meij, Henk 
> [hmeij at wesleyan.edu]
> Sent: Thursday, October 23, 2014 9:57 AM
> To: Philipp Reisner; drbd-user at lists.linbit.com
> Subject: Re: [DRBD-user] drbd storage size
>
> Thanks for the write up y'll.  I'll have to think about #3 not sure I 
> grasp it fully.
>
> Last night I started a 12 TB test and started first initialization for 
> observation (0 is primary).
> I have node0:eth1 wired directly into node1:eth1 with 10 foot CAT 6 cable 
> (MTU=9000)
> Data from node1 to node0
> PING 10.10.52.232 (10.10.52.232) 8970(8998) bytes of data.
> 8978 bytes from 10.10.52.232: icmp_seq=1 ttl=64 time=0.316 ms
>
> This morning's progress report from node1:(drbd v8.4.5)
>
>        [===>................] sync'ed: 21.7% (8847740/11287100)M
>        finish: 62:50:50 speed: 40,032 (39,008) want: 68,840 K/sec
>
> which confuses me: 8.8M out of 11.3M is 77.8% synced, not? I will let this 
> test finish before I do a dd attempt.
>
> iostat reveals %idle cpu 99%+ and little to no %iowait (near 0%), iotop 
> confirms very little IO (<5 K/s), typical data
> Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz 
> avgqu-sz   await  svctm  %util
> sdb1              0.00   231.00    0.00  156.33     0.00 79194.67   506.58 
> 0.46    2.94   1.49  23.37
>
> Something is throttling this IO as 40M/s is about half of what I was 
> hoping for. Will dig some more.
>
> -Henk
>
> ________________________________________
> From: drbd-user-bounces at lists.linbit.com 
> [drbd-user-bounces at lists.linbit.com] on behalf of Philipp Reisner 
> [philipp.reisner at linbit.com]
> Sent: Thursday, October 23, 2014 9:17 AM
> To: drbd-user at lists.linbit.com
> Subject: Re: [DRBD-user] drbd storage size
>
> Am Donnerstag, 23. Oktober 2014, 08:55:03 schrieb Digimer:
>> On 23/10/14 04:00 AM, Philipp Reisner wrote:
>> > 2a) Initialize both backend devices to a known state.
>> >
>> >      I.e. dd if=/dev/zero of=/dev/sdb1 bs=$((1024*1024)) oflag=direct
>>
>> Question;
>>
>>    What I've done in the past to speed up initial sync is to create the
>> DRBD device, pause-sync, then do your 'dd if=/dev/zero ...' trick to
>> /dev/drbd0. This effectively drives the resync speed to the max possible
>> and ensures full sync across both nodes. Is this a sane approach?
>>
>
> Yes, sure that is a way to do it. (I have the impression that is something
> form the drbd-8.3 world.)
>
> I do not know from the top of the head if that will be faster than the
> built-in background resync in drbd-8.4.
>
> Best,
> Phil
>
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