Hi!
At the time of writing we set N to 1200 , but we are not sure if it would be
better to set to overestimated 5000 ?
We use 6 backend nodes
The backend storage is a Flash9100 for metadata and 6x Lenovo DE6000H . We will
finally use 2 filesystems : data and home
Fs “data” consist of 12 metadada-nsd and 72 dataonly nsds
We have enough space to add nsds (finally the fs
[root@nsd75-01 ~]# mmlspool data
Storage pools in file system at '/gpfs/data':
Name Id BlkSize Data Meta Total Data in (KB) Free Data
in (KB) Total Meta in (KB) Free Meta in (KB)
system 0 4 MB no yes 0 0 (
0%) 12884901888 12800315392 ( 99%)
saspool 65537 4 MB yes no 1082331758592 1082326446080
(100%) 0 0 ( 0%)
[root@nsd75-01 ~]# mmlsfs data
flag value description
------------------- ------------------------ -----------------------------------
-f 8192 Minimum fragment (subblock) size in
bytes
-i 4096 Inode size in bytes
-I 32768 Indirect block size in bytes
-m 1 Default number of metadata replicas
-M 2 Maximum number of metadata replicas
-r 1 Default number of data replicas
-R 2 Maximum number of data replicas
-j scatter Block allocation type
-D nfs4 File locking semantics in effect
-k all ACL semantics in effect
-n 1200 Estimated number of nodes that will
mount file system
-B 4194304 Block size
-Q user;group;fileset Quotas accounting enabled
user;group;fileset Quotas enforced
fileset Default quotas enabled
--perfileset-quota Yes Per-fileset quota enforcement
--filesetdf Yes Fileset df enabled?
-V 21.00 (5.0.3.0) File system version
--create-time Fri Feb 7 15:32:05 2020 File system creation time
-z No Is DMAPI enabled?
-L 33554432 Logfile size
-E Yes Exact mtime mount option
-S relatime Suppress atime mount option
-K whenpossible Strict replica allocation option
--fastea Yes Fast external attributes enabled?
--encryption No Encryption enabled?
--inode-limit 1342177280 Maximum number of inodes
--log-replicas 0 Number of log replicas
--is4KAligned Yes is4KAligned?
--rapid-repair Yes rapidRepair enabled?
--write-cache-threshold 0 HAWC Threshold (max 65536)
--subblocks-per-full-block 512 Number of subblocks per full block
-P system;saspool Disk storage pools in file system
--file-audit-log No File Audit Logging enabled?
--maintenance-mode No Maintenance Mode enabled?
-d
de750101vol01;de750101vol02;de750101vol03;de750101vol04;de750101vol05;de750101vol06;de750102vol01;de750102vol02;de750102vol03;de750102vol04;de750102vol05;de750102vol06;
-d
de750201vol01;de750201vol02;de750201vol03;de750201vol04;de750201vol05;de750201vol06;de750202vol01;de750202vol02;de750202vol03;de750202vol04;de750202vol05;de750202vol06;
-d
de760101vol01;de760101vol02;de760101vol03;de760101vol04;de760101vol05;de760101vol06;de760102vol01;de760102vol02;de760102vol03;de760102vol04;de760102vol05;de760102vol06;
-d
de760201vol01;de760201vol02;de760201vol03;de760201vol04;de760201vol05;de760201vol06;de760202vol01;de760202vol02;de760202vol03;de760202vol04;de760202vol05;de760202vol06;
-d
de770101vol01;de770101vol02;de770101vol03;de770101vol04;de770101vol05;de770101vol06;de770102vol01;de770102vol02;de770102vol03;de770102vol04;de770102vol05;de770102vol06;
-d
de770201vol01;de770201vol02;de770201vol03;de770201vol04;de770201vol05;de770201vol06;de770202vol01;de770202vol02;de770202vol03;de770202vol04;de770202vol05;de770202vol06;
-d
globalmeta0;globalmeta1;globalmeta2;globalmeta3;globalmeta4;globalmeta5;globalmeta6;globalmeta7;globalmeta8;globalmeta9;globalmeta10;globalmeta11
Disks in file system
-A yes Automatic mount option
-o none Additional mount options
-T /gpfs/data Default mount point
--mount-priority 0 Mount priority
##
For fs Home we use 24 dataAdnMetadata disks only on flash
[root@nsd75-01 ~]# mmlspool home
Storage pools in file system at '/gpfs/home':
Name Id BlkSize Data Meta Total Data in (KB) Free Data
in (KB) Total Meta in (KB) Free Meta in (KB)
system 0 1024 KB yes yes 25769803776 25722931200
(100%) 25769803776 25722981376 (100%)
[root@nsd75-01 ~]#
[root@nsd75-01 ~]# mmlsfs home
flag value description
------------------- ------------------------ -----------------------------------
-f 8192 Minimum fragment (subblock) size in
bytes
-i 4096 Inode size in bytes
-I 32768 Indirect block size in bytes
-m 1 Default number of metadata replicas
-M 2 Maximum number of metadata replicas
-r 1 Default number of data replicas
-R 2 Maximum number of data replicas
-j scatter Block allocation type
-D nfs4 File locking semantics in effect
-k all ACL semantics in effect
-n 1200 Estimated number of nodes that will
mount file system
-B 1048576 Block size
-Q user;group;fileset Quotas accounting enabled
user;group;fileset Quotas enforced
fileset Default quotas enabled
--perfileset-quota Yes Per-fileset quota enforcement
--filesetdf Yes Fileset df enabled?
-V 21.00 (5.0.3.0) File system version
--create-time Fri Feb 7 15:31:28 2020 File system creation time
-z No Is DMAPI enabled?
-L 33554432 Logfile size
-E Yes Exact mtime mount option
-S relatime Suppress atime mount option
-K whenpossible Strict replica allocation option
--fastea Yes Fast external attributes enabled?
--encryption No Encryption enabled?
--inode-limit 25166080 Maximum number of inodes
--log-replicas 0 Number of log replicas
--is4KAligned Yes is4KAligned?
--rapid-repair Yes rapidRepair enabled?
--write-cache-threshold 0 HAWC Threshold (max 65536)
--subblocks-per-full-block 128 Number of subblocks per full block
-P system Disk storage pools in file system
--file-audit-log No File Audit Logging enabled?
--maintenance-mode No Maintenance Mode enabled?
-d
home0;home10;home11;home12;home13;home14;home15;home16;home17;home18;home19;home1;home20;home21;home22;home23;home2;home3;home4;home5;home6;home7;home8;home9
Disks in file system
-A yes Automatic mount option
-o none Additional mount options
-T /gpfs/home Default mount point
--mount-priority 0 Mount priority
[root@nsd75-01 ~]#
Mit freundlichen Grüßen
Walter Sklenka
Technical Consultant
EDV-Design Informationstechnologie GmbH
Giefinggasse 6/1/2, A-1210 Wien
Tel: +43 1 29 22 165-31
Fax: +43 1 29 22 165-90
E-Mail: [email protected]<mailto:[email protected]>
Internet: www.edv-design.at<http://www.edv-design.at/>
Von: [email protected]
<[email protected]> Im Auftrag von José Filipe Higino
Gesendet: Saturday, February 8, 2020 1:00 PM
An: gpfsug main discussion list <[email protected]>
Betreff: Re: [gpfsug-discuss] mmdf and maybe other commands long running //
influence of n and B on number of regions
How many back end nodes for that cluster? and how many filesystems for that
same access... and how many pools for the same data access type (12 ndisks
sounds very LOW to me, for that size of a cluster, probably no other filesystem
can do more than that). On GPFS there are so many different ways to access the
data, that is sometimes hard to start a conversation. And you did a very great
job of introducing it. =)
We (I am a customer too) do not have that many nodes, but from experience, I
know some clusters (and also multicluster configs) depend mostly on how much
metadata you can service in the network and how fast (latency wise) you can do
it, to accommodate such amount of nodes. There is never design by the book that
can safely tell something will work 100% times. But the beauty of it is that
GPFS allows lots of aspects to be resized at your convenience to facilitate
what you need most the system to do.
Let us know more...
On Sun, 9 Feb 2020 at 00:40, Walter Sklenka
<[email protected]<mailto:[email protected]>> wrote:
Hello!
We are designing two fs where we cannot anticipate if there will be 3000, or
maybe 5000 or more nodes totally accessing these filesystems
What we saw, was that execution time of mmdf can last 5-7min
We openend a case and they said, that during such commands like mmdf or also
mmfsck, mmdefragfs,mmresripefs all regions must be scanned at this is the
reason why it takes so long
The technichian also said, that it is “rule of thumb” that there should be
(-n)*32 regions , this would then be enough ( N=5000 --> 160000 regions per
pool ?)
(also Block size has influence on regions ?)
#mmfsadm saferdump stripe
Gives the regions number
storage pools: max 8
alloc map type 'scatter'
0: name 'system' Valid nDisks 12 nInUse 12 id 0 poolFlags 0 thinProvision
reserved inode -1, reserved nBlocks 0
regns 170413 segs 1 size 4096 FBlks 0 MBlks 3145728 subblock size 8192
We also saw when creating the filesystem with a speciicic (-n) very high
(5000) (where mmdf execution time was some minutes) and then changing (-n) to
a lower value this does not influence the behavior any more
My question is: Is the rule (Number of Nodes)x5000 for number of regios in a
pool an good estimation ,
Is it better to overestimate the number of Nodes (lnger running commands) or is
it unrealistic to get into problems when not reaching the regions number
calculated ?
Does anybody have experience with high number of nodes (>>3000) and how to
design the filesystems for such large clusters ?
Thank you very much in advance !
Mit freundlichen Grüßen
Walter Sklenka
Technical Consultant
EDV-Design Informationstechnologie GmbH
Giefinggasse 6/1/2, A-1210 Wien
Tel: +43 1 29 22 165-31
Fax: +43 1 29 22 165-90
E-Mail: [email protected]<mailto:[email protected]>
Internet: www.edv-design.at<http://www.edv-design.at/>
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