Re: [Moosefs-users] Chunks

[Heiko S. <sch...@iu...>]

Am Samstag 26 Februar 2011, um 14:27:34 schrieb Heiko Schröter:
> On Fri, 25 Feb 2011 11:21:33 +0100
> "Michal Borychowski" <mic...@ge...> wrote:
> 
> > Hi!
> > 
> > If you set goal=1, all chunks belonging to the same file will go to the same
> > chunk server.
> Supposed to, but it does not work this way.
> 
> In our test setup (one master, one client, two chunkservers) the chunks are beeing spread across the two chunkservers, even with "goal=1".
> df on on the chunksrevr clearly shows that the files are spread evenly across them.
> 
> mfsfileinfo shows that the chunks are placed alternatingly on the chunk servers.
> Incrementing "goal" only increases the number of copies.
> 
> Screenshots can be supplied on tuesday since our server room is under reconstruction over the weekend.
> 
> Heiko
> 

Ok here we go:

Installed OS,mfs on all systems:
2.6.36-gentoo-r5 x86_64
mfs-1.6.20
fuse-2.8.5

chunkserv1: 192.168.16.54
chunkserv2: 192.168.16.147

df on Chunkservers before cp:
chunkserv1 ~ # df -h /mnt/mfschunks*
Filesystem            Size  Used Avail Use% Mounted on
/dev/sdb              5.5T   97M  5.5T   1% /mnt/mfschunks1
/dev/sdc              5.5T   33M  5.5T   1% /mnt/mfschunks2
chunkserv2 ~ # df -h /mnt/mfschunks*
Filesystem            Size  Used Avail Use% Mounted on
/dev/sdb              2.8T   33M  2.8T   1% /mnt/mfschunks1
/dev/sdc              2.8T   33M  2.8T   1% /mnt/mfschunks2
/dev/sdd              2.8T   33M  2.8T   1% /mnt/mfschunks3



client ~ # mkdir /mnt/mfs/folder1   
client ~ # mfssetgoal -r 1 /mnt/mfs/folder1/
/mnt/mfs/folder1/:
 inodes with goal changed:                         0
 inodes with goal not changed:                     1
 inodes with permission denied:                    0

client ~ # dd if=/dev/urandom of=/tmp/ttt.dat bs=100M count=5
5+0 records in
5+0 records out
524288000 bytes (524 MB) copied, 83.5789 s, 6.3 MB/s
client ~ # cp /tmp/ttt.dat /mnt/mfs/folder1/ttt.dat

client ~ # mfsfileinfo /mnt/mfs/folder1/ttt.dat 
/mnt/mfs/folder1/ttt.dat:
        chunk 0: 0000000000000AC3_00000001 / (id:2755 ver:1)
                copy 1: 192.168.16.54:9422
        chunk 1: 0000000000000AC4_00000001 / (id:2756 ver:1)
                copy 1: 192.168.16.147:9422
        chunk 2: 0000000000000AC5_00000001 / (id:2757 ver:1)
                copy 1: 192.168.16.54:9422
        chunk 3: 0000000000000AC6_00000001 / (id:2758 ver:1)
                copy 1: 192.168.16.147:9422
        chunk 4: 0000000000000AC7_00000001 / (id:2759 ver:1)
                copy 1: 192.168.16.147:9422
        chunk 5: 0000000000000AC8_00000001 / (id:2760 ver:1)
                copy 1: 192.168.16.54:9422
        chunk 6: 0000000000000AC9_00000001 / (id:2761 ver:1)
                copy 1: 192.168.16.147:9422
        chunk 7: 0000000000000ACA_00000001 / (id:2762 ver:1)
                copy 1: 192.168.16.54:9422

client ~ # mfsgetgoal /mnt/mfs/folder1/ttt.dat 
/mnt/mfs/folder1/ttt.dat: 1
client ~ # mfsgetgoal /mnt/mfs/folder1         
/mnt/mfs/folder1: 1

df on Chunkservers after cp:
chunkserv1 ~ # df -h /mnt/mfschunks*
Filesystem            Size  Used Avail Use% Mounted on
/dev/sdb              5.5T  225M  5.5T   1% /mnt/mfschunks1
/dev/sdc              5.5T  161M  5.5T   1% /mnt/mfschunks2
chunkserv2 ~ # df -h /mnt/mfschunks*
Filesystem            Size  Used Avail Use% Mounted on
/dev/sdb              2.8T  149M  2.8T   1% /mnt/mfschunks1
/dev/sdc              2.8T   97M  2.8T   1% /mnt/mfschunks2
/dev/sdd              2.8T   97M  2.8T   1% /mnt/mfschunks3


Regards
Heiko