Gluster users - Jul 2016 - New cluster - first experience

On 7/07/2016 9:52 PM, Gandalf Corvotempesta wrote:
> Volume Name: gv0
> Type: Replicate
> Volume ID: 2a36dc0f-1d9b-469c-82de-9d8d98321b83
> Status: Started
> Number of Bricks: 1 x 3 = 3
> Transport-type: tcp
> Bricks:
> Brick1: 77.95.175.112:/export/sdb1/brick
> Brick2: 77.95.175.113:/export/sdb1/brick
> Brick3: 77.95.175.114:/export/sdb1/brick
> Options Reconfigured:
> features.shard: on
> transport.address-family: inet
> performance.readdir-ahead: on
> nfs.disable: on
The default shard size is 4MB, I'd tend towards a larger one which 
improves write speed. For my VM cluster I use shardsize = 64MB


nb. To change the shardsize you should recreate the volume.

-- 
Lindsay Mathieson

2016-07-07 14:04 GMT+02:00 Lindsay Mathieson <lindsay.mathieson at
gmail.com>:
> nb. To change the shardsize you should recreate the volume.
There is no need to recreate the volume.
Shard size is an option to set, not a parameter during the volume creation.

I did the following:
# gluster volume set dis-rep features.shard-block-size 64MB

and shard size changed properly. Then I've created a 1GB file and it
was sharded in 15 chunks

2016-07-07 14:04 GMT+02:00 Lindsay Mathieson <lindsay.mathieson at
gmail.com>:
> The default shard size is 4MB, I'd tend towards a larger one which
improves
> write speed. For my VM cluster I use shardsize = 64MB
Whis the following:

# gluster volume info gv0

Volume Name: gv0
Type: Replicate
Volume ID: 2a36dc0f-1d9b-469c-82de-9d8d98321b83
Status: Started
Number of Bricks: 1 x 3 = 3
Transport-type: tcp
Bricks:
Brick1: 77.95.175.112:/export/sdb1/brick
Brick2: 77.95.175.113:/export/sdb1/brick
Brick3: 77.95.175.114:/export/sdb1/brick
Options Reconfigured:
features.shard-block-size: 64MB
features.shard: on
transport.address-family: inet
performance.readdir-ahead: on
nfs.disable: on

i'm still stuck at 10m35.507s

I only have 1GB connection, thus 1GB/3 should be the maximum speed.
1000/3/8 = about 40MB/s

# du -sh linux-4.7-rc6
632M linux-4.7-rc6

632M / 40 = 15.8 seconds.

It should take 15.8 seconds to extract.

2016-07-07 14:04 GMT+02:00 Lindsay Mathieson <lindsay.mathieson at
gmail.com>:
> The default shard size is 4MB, I'd tend towards a larger one which
improves
> write speed. For my VM cluster I use shardsize = 64MB
>
> nb. To change the shardsize you should recreate the volume.
I did more test.
Is not a shard issue, with shard enabled:

# dd if=/dev/zero of=/mnt/glusterfs/zero1 bs=1M count=1000
1000+0 record dentro
1000+0 record fuori
1048576000 byte (1,0 GB) copiati, 93,8803 s, 11,2 MB/s

With shard disabled:

# dd if=/dev/zero of=/mnt/glusterfs/zero2 bs=1M count=1000
1000+0 record dentro
1000+0 record fuori
1048576000 byte (1,0 GB) copiati, 100,051 s, 10,5 MB/s

mostly the same.



# iperf -c 1.2.3.4
------------------------------------------------------------
Client connecting to 1.2.3.4, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[  3] local 1.2.3.5 port 34357 connected with 1.2.3.4 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.10 GBytes   943 Mbits/sec