Re: mkfs or crfs

On Mon, Jun 30, 2008 at 7:55 AM, Davignon, Edward <
Edward.Davignon@xxxxxxxxxxxxxx> wrote:

I use:
sudo /usr/bin/su - root -c some_command


You dont need -root for sudo - just "-" is enough :)


you could set this to an alias or put it in a script.

-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
AIX
Sent: Monday, June 30, 2008 12:19 AM
To: aix-l@xxxxxxxxxxxxx
Subject: Re: mkfs or crfs

I just noticed that sudo was reading my user id's ulimit,
And that was the reason Legato software or cp couldn't
Copy files greater than 2 G.

Any one knows how to force sudo read the ulimit of the root user ?





-----Original Message-----
From: AIX [mailto:aix@xxxxxxxxxxxxxx]
Sent: Sunday, June 29, 2008 5:01 PM
To: 'IBM AIX Discussion List'
Subject: RE: mkfs or crfs

Thanks,

I have created a jfs file system, and now in process of copying files,
But found that due to being AIX 4.3, our legato software can't restore
files
Greater than 2 GB, so tried different method but still has the same
problem.

- cpio can't copy files greater than 2GB.
- cp returns error on some files.
- rsync also returns error on some files.

Now my question is , on AIX 4.3 what is the best method of moving data
Bigger than 2G while file might be open by oracle instance ?

Thanks for all your help


-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
Green, Simon
Sent: Tuesday, June 24, 2008 5:02 AM
To: aix-l@xxxxxxxxxxxxx
Subject: Re: mkfs or crfs

Just been re-reading the LVM A-Z redbook. That does state that the
JFSlog is limited to 256MB. There's also a bit more information on the
JFSlog in general which you might find interesting. In particular see
5.2.7.9 & 5.3.

http://www.redbooks.ibm.com/abstracts/sg245432.html?Open

--
Simon

-----Original Message-----
From: Green, Simon
Sent: 23 June 2008 17:38
To: 'IBM AIX Discussion List'
Subject: RE: mkfs or crfs

Well, it does say "In general...". Like all such guidelines it won't
apply to all cases.

If it were me, I'd create a log of just one partition - which I guess
would be something like 128MB, but that'll depend on your particular
config - and be quite comfortable.

You should note that a JSF log is not like an Oracle log, which records
changes to data for purposes of forward/backward recovery. A JFSlog
only records changes to the filesystem's structure. E.g. Creating a new
file, or extending an existing file onto another block. So just because
there's a lot of I/O activity to a filesystem that doesn't mean that the
JFSlog is going to be hit particularly hard.

If there is a limit of 256MB on a JFSlog - which I wasn't aware of - you
don't have much option: you CAN NOT use more than one log for a single
filesystem.

But I think you're worry over nothing.

--
Simon Green

-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
AIX
Sent: 23 June 2008 12:43
To: aix-l@xxxxxxxxxxxxx
Subject: Re: mkfs or crfs

Here is the link that says we should have 2 MB jfslog for each 1 GB jfs
filesystem,

http://www-1.ibm.com/support/docview.wss?uid=isg3T1000398#increase

And got following warning, when I did logform to format the jfslog which
is
bigger than 256 MB

logform /dev/bkuploglv3
WARNING: log size greater than one segment
Only 256MB of log will be used
logform: destroy /dev/bkuploglv3 (y)?yes

the filesystem that I am going to create, is used for Oracle hot backup
and
crontab
is writing to it every 5 or 10 minutes, so my concern is if one jfslog
would
be
enough for 500 GB jfs.

Unfortunately we are using AIX 4.3.1 which has no jfs2.




-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
Green, Simon
Sent: Monday, June 23, 2008 3:57 AM
To: aix-l@xxxxxxxxxxxxx
Subject: Re: mkfs or crfs

Where are you getting your information?
A JFS can only have one JFSlog. A log can (and usually does) service
multiple filesystems.
Your space estimates are way off. The space requirement depends a lot
on the amount and type of activity in the filesystem. Most of the ones
I set up are just a single partition and that's fine. You might want to
make yours a bit bigger if you're really worried, but I doubt it'll be a
problem. If it's too small, it's not the end of the world, although you
can't extend a JFSlog whilst any of its filesystems are mounted.

What's this going to be used for? If it's a database - e.g. Oracle -
you've probably got nothing to worry about as these put very little load
on the JFSlog in my experience. The only times I've ever had problems
(as far as I can recall) are with generally small volume groups
containing several small but highly active filesystems with loads of
small files; mainly rootvg, which is a bit of a pain and a good reason
for keeping non-system filesystems in external volume groups.

--
Simon Green

-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
AIX
Sent: 22 June 2008 22:30
To: aix-l@xxxxxxxxxxxxx
Subject: Re: mkfs or crfs

It seems that jfs file system can have several jfslog,
But now the question is how to load balance a 500 GB filesystem over 3
different jfslog ?
And how do I know which jfslog will be used for filesystem.

Thanks for help

-----Original Message-----
From: AIX [mailto:aix@xxxxxxxxxxxxxx]
Sent: Sunday, June 22, 2008 3:47 PM
To: 'IBM AIX Discussion List'
Subject: RE: mkfs or crfs

Hi

How can I resolve the jfslog problem then ?
IBM recommends 2MB of jfslog for each 2GB of filesystem,
However Jfslog can not be more than 256 Megabyte and I can only have one
jfslog for new filesystem.


-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
Mills, John T
Sent: Wednesday, June 11, 2008 8:01 AM
To: aix-l@xxxxxxxxxxxxx
Subject: Re: mkfs or crfs

Subject: Re: mkfs or crfs

On Tue, Jun 10, 2008 at 07:43:08PM -0500, AIX wrote:
Hi

Is there any difference between crfs and mkfs on AIX ?
And what is the practical maximum jfs file system on AIX 4.3.

crfs is by far the eaiser way to make a jfs filesystem on AIX.

You say 'practical' here, so I guess it depends on the number of
files
or size of files you will have in this filesystem. The maxiumum size
of an AIX 4.3 filesystem (depending on nbpi and fragment size) is
1TB.

Maximum size of a file is 2GB in a normal jfs, and in a 'large file
enabled'
jfs it is 64GB.

hth,

bob


Remember to pay close attention to the nbpi of the file system at build
time. It can't be altered after creation. I haven't done anything
larger than 500GB in jfs for production. The restriction was fsck
timings.

John T. Mills

from man crfs:
The maximum size of a JFS file system is a function of its
fragment size and the NBPI value. These values yield the following size
restrictions:

NBPI Minimum AG Size Fragment Size Maximum Size
(GB)
512 8 512, 1024, 2048, 4096 8
1024 8 512, 1024, 2048, 4096 16
2048 8 512, 1024, 2048, 4096 32
4096 8 512, 1024, 2048, 4096 64
8192 8 512, 1024, 2048, 4096 128
16384 8 1024, 2048, 4096 256
32768 16 2048, 4096 512

65536 32 4096 1024
131072 64 4096 1024




--
Regards., Blazej Antczak
-= Did U even tried to figure out woman with man? #man woman --> core
dumped, sys error =-

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