ADSM-L

Re: [ADSM-L] nfs mounted tsm storage becoming unavailable

2015-09-10 09:47:44
Subject: Re: [ADSM-L] nfs mounted tsm storage becoming unavailable
From: "Loon, EJ van (ITOPT3) - KLM" <Eric-van.Loon AT KLM DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Thu, 10 Sep 2015 13:36:02 +0000
Hi Shawn!
Sparse files are created while the actual storage is allocated when needed. So 
the actuals disk space is allocated at the moment you are filling your diskpool 
volumes for the first time. If this is true, you're diskpool files will be 
heavily fragmented...
Kind regards,
Eric van Loon
AF/KLM Storage Engineering

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Shawn Drew
Sent: woensdag 9 september 2015 17:15
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: nfs mounted tsm storage becoming unavailable

It depends on the file system the volume is created on. Ext4 and JFS support 
sparse file creation and TSM takes advantage of it. NFS does not. Search the 
admin guide for "preallocated" for info.

On Wed, Sep 9, 2015 at 10:51 AM, Loon, EJ van (ITOPT3) - KLM <Eric-van.Loon AT 
klm DOT com> wrote:
Smarter way of formatting? Either it fills the files with zero's or with a 
certain text string like in 5.5, formatting takes time. Allocating a 100 Gb 
files currently takes a few seconds, so it's impossible that TSM physically 
formats a file.
Kind regards,
Eric van Loon
AF/KLM Storage Engineering

-----Original Message-----
 From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
Of Remco Post
Sent: woensdag 9 september 2015 14:17
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: nfs mounted tsm storage becoming unavailable

Op 9 sep. 2015, om 09:11 heeft "Loon, EJ van (ITOPT3) - KLM"
<Eric-van.Loon AT KLM DOT COM> het volgende geschreven:

 > Hi Rick!
 > Formatting the whole volume was the case in the TSM 5.5 era, but not anymore.

not true, but TSM does attempt smarter ways of formatting, so it seems faster  
from your perspective.

What is important is that TSM uses a particular kind of file locking, something 
that doesn't work for every combination of NFS client and server. See:
https://www-304.ibm.com/support/docview.wss?uid=swg21470193

 > Formatting a diskpool or filepool volume took ages back then because it was 
 > filed with a text string (my name backwards :-), but with version 6 this has 
 > changed and it just pre-allocates the requested space without formatting.
Creating a volume is now a matter of seconds, no matter how large it is.
 > Kind regards,
 > Eric van Loon
 > AF/KLM Storage Engineering
 >
 > -----Original Message-----
 > From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
 > Of Rhodes, Richard L.
 > Sent: dinsdag 8 september 2015 18:49
 > To: ADSM-L AT VM.MARIST DOT EDU
 > Subject: Re: nfs mounted tsm storage becoming unavailable  >  > It sounds 
 > like you are pre-defining the file vols on the NFS share.
 > If you pre-define vols I believe TSM writes the entire vol to initialize it.
That would be a very heavy write load. It sounds like maybe the NFS server is 
overloaded and maybe causing I/O errors to the other TSM's.
 >
 > Are you seeing ANR errors in the actlog of any of the TSM servers when this 
 > problem occurs?
 >
 > I'd check the network stats for your TSM server and NFS server.
 > Possibly getting lan errors under heavy load is causing problems.
 >
 > Are your NFS shares mounted hard? I believe they should be.
 >
 > Run around - don't pre-define vols, let TSM to create scratch vols as needed.
 > That's what we do for our NFS DataDomain shares.
 >
 > Just some thoughts!
 >
 > Rick
 >
 >
 >
 > -----Original Message-----
 > From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
 > Of Lee, Gary  > Sent: Tuesday, September 08, 2015 10:38 AM  > To: ADSM-L AT 
 > VM.MARIST DOT EDU  > Subject: nfs mounted tsm storage becoming unavailable  
 > >  > We are trying to troubleshoot a problem with our tsm disk storage.
 >
 > Tsm server 6.3.4 running on RHEL 6.5.
 > Our storage is a set of subdirectories on a file system mounted via nfs
v3 to
all three of our tsm servers.
 >
 > All goes fine until an attempt is made to define one or more volumes to a 
 > storage pool.
 > At that time, if other tsm servers are writing to the storage, those volumes 
 > will become red-only when the volume define is in process.
 >
 > Other operations, such as reclamation, and normal writing do not cause 
 > problems.
 >
 > Our storage provider, (nexenta) is asking what tsm does when creating a 
 > storage volume.
 > So, I am coming to the list for information. Just what does tsm do under the 
 > covers when defining a storage volume?
 >
 > Thanks for any help.
 >
 >
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received this e-mail by error, please notify the sender immediately by return 
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Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its 
employees shall not be liable for the incorrect or incomplete transmission of 
this e-mail or any attachments, nor responsible for any delay in receipt.
Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch
Airlines) is registered in Amstelveen, The Netherlands, with registered number
33014286
********************************************************
********************************************************
For information, services and offers, please visit our web site: 
http://www.klm.com. This e-mail and any attachment may contain confidential and 
privileged material intended for the addressee only. If you are not the 
addressee, you are notified that no part of the e-mail or any attachment may be 
disclosed, copied or distributed, and that any other action related to this 
e-mail or attachment is strictly prohibited, and may be unlawful. If you have 
received this e-mail by error, please notify the sender immediately by return 
e-mail, and delete this message. 

Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its 
employees shall not be liable for the incorrect or incomplete transmission of 
this e-mail or any attachments, nor responsible for any delay in receipt. 
Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch 
Airlines) is registered in Amstelveen, The Netherlands, with registered number 
33014286
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