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Forum Topic - qnx6f max file number: (5 Items)

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Mario Charest

09/20/2010 9:00 AM

post67848

Is it unrealistic or does it have some sort of negative impact to have a 2TB disk with qnx6fs and specify something like
 -i 100M ( 100 millions) to mkqnx6fs ?

By the way would be nice if the doc on mkqnx6fs would specify the exact numbers use by the -T option.

Thanks

David Sarrazin

09/20/2010 9:54 AM

post67858

RE: qnx6f max file number

Each inode requires 128 bytes, so 100M inodes is 12.8GB, plus the
indirect blocks.  Finding a free inode in a mostly-full system would be
time expensive at that scale.  What you are saying is that you expect
your 2TB drive to be filled up with 10KByte average-sized files.  Having
said that, I know that the test group here has a 2TB server set up with
10M inodes.

mkqnx6fs uses the hint of -T to guess at the average file size.  The
number of inodes are then selected based on that.

The (current, but might change) values are:

Desktop:  1024 byte block,  8 blocks/file
Media:    2048 byte block,  512 blocks/file
Runtime:  1024 byte block, 32blocks/file
 
David

> -----Original Message-----
> From: Mario Charest [mailto:community-noreply@qnx.com] 
> Sent: September 20, 2010 9:01 AM
> To: general-filesystems
> Subject: qnx6f max file number
> 
> Is it unrealistic or does it have some sort of negative 
> impact to have a 2TB disk with qnx6fs and specify something 
> like -i 100M ( 100 millions) to mkqnx6fs ?
> 
> By the way would be nice if the doc on mkqnx6fs would specify 
> the exact numbers use by the -T option.
> 
> Thanks
> 
> 
> 
> _______________________________________________
> 
> General
> http://community.qnx.com/sf/go/post67848
> 
>

Mario Charest

09/20/2010 1:51 PM

post67901

RE: qnx6f max file number


> -----Message d'origine-----
> De : David Sarrazin [mailto:community-noreply@qnx.com]
> Envoyé : 20 septembre 2010 09:55
> À : general-filesystems
> Objet : RE: qnx6f max file number
> 
> Each inode requires 128 bytes, so 100M inodes is 12.8GB, plus the indirect
> blocks.  Finding a free inode in a mostly-full system would be time expensive
> at that scale.  What you are saying is that you expect your 2TB drive to be
> filled up with 10KByte average-sized files.  Having said that, I know that the
> test group here has a 2TB server set up with 10M inodes.
> 
That would be 20K files ;-)  I exaggerated that number a bit to get a good idea. Files will be 400K so 5 millions would 
be closer to what we need.

Can you define 'time expensive'?  The hardware driver will operate almost 90% full, with around 100 files new files 
written and the 100 oldest files deleted.

Thanks David.

> mkqnx6fs uses the hint of -T to guess at the average file size.  The number of
> inodes are then selected based on that.
> 
> The (current, but might change) values are:
> 
> Desktop:  1024 byte block,  8 blocks/file
> Media:    2048 byte block,  512 blocks/file
> Runtime:  1024 byte block, 32blocks/file
> 
> David
> 
> > -----Original Message-----
> > From: Mario Charest [mailto:community-noreply@qnx.com]
> > Sent: September 20, 2010 9:01 AM
> > To: general-filesystems
> > Subject: qnx6f max file number
> >
> > Is it unrealistic or does it have some sort of negative impact to have
> > a 2TB disk with qnx6fs and specify something like -i 100M ( 100
> > millions) to mkqnx6fs ?
> >
> > By the way would be nice if the doc on mkqnx6fs would specify the
> > exact numbers use by the -T option.
> >
> > Thanks
> >
> >
> >
> > _______________________________________________
> >
> > General
> > http://community.qnx.com/sf/go/post67848
> >
> >
> 
> 
> 
> _______________________________________________
> 
> General
> http://community.qnx.com/sf/go/post67858
>

Mario Charest

01/24/2011 7:26 PM

post82603

Re: RE: qnx6f max file number

> 
> 
> > -----Message d'origine-----
> > De : David Sarrazin [mailto:community-noreply@qnx.com]
> > Envoyé : 20 septembre 2010 09:55
> > À : general-filesystems
> > Objet : RE: qnx6f max file number
> > 
> > Each inode requires 128 bytes, so 100M inodes is 12.8GB, plus the indirect
> > blocks.  Finding a free inode in a mostly-full system would be time 
> expensive
> > at that scale.  What you are saying is that you expect your 2TB drive to be
> > filled up with 10KByte average-sized files.  Having said that, I know that 
> the
> > test group here has a 2TB server set up with 10M inodes.
> > 
> That would be 20K files ;-)  I exaggerated that number a bit to get a good 
> idea. Files will be 400K so 5 millions would be closer to what we need.
> 
> Can you define 'time expensive'?  The hardware driver will operate almost 90% 
> full, with around 100 files new files written and the 100 oldest files deleted
> .

Given mkqnx6fs -i12000000 on a 2Terabyte disk filled at 8% is it possible that a write of 20 files (20Meg) will cause 
the filesystem to freeze for 10-20Sec ?



>

David Sarrazin

01/25/2011 11:20 AM

post82634

RE: RE: qnx6f max file number

-----Original Message-----
From: Mario Charest [mailto:community-noreply@qnx.com] 
Sent: January-24-11 7:26 PM
To: general-filesystems
Subject: Re: RE: qnx6f max file number

> 
> 
> > -----Message d'origine-----
> > De : David Sarrazin [mailto:community-noreply@qnx.com]
> > Envoyé : 20 septembre 2010 09:55
> > À : general-filesystems
> > Objet : RE: qnx6f max file number
> > 
> > Each inode requires 128 bytes, so 100M inodes is 12.8GB, plus the indirect
> > blocks.  Finding a free inode in a mostly-full system would be time 
> expensive
> > at that scale.  What you are saying is that you expect your 2TB drive to be
> > filled up with 10KByte average-sized files.  Having said that, I know that 
> the
> > test group here has a 2TB server set up with 10M inodes.
> > 
> That would be 20K files ;-)  I exaggerated that number a bit to get a good 
> idea. Files will be 400K so 5 millions would be closer to what we need.
> 
> Can you define 'time expensive'?  The hardware driver will operate almost 90% 
> full, with around 100 files new files written and the 100 oldest files deleted
> .

Given mkqnx6fs -i12000000 on a 2Terabyte disk filled at 8% is it possible that a write of 20 files (20Meg) will cause 
the filesystem to freeze for 10-20Sec ?

I would expect no.  If you've used up most of the inodes, and have just a few free holes spread about in the inodes file
, then finding a free inode will incur a search through the file (a hint to where to start searching is stored).  If 
this was a new filesystem, the inodes file will be almost entirely free, and finding new entries will be very fast.

Does a KEV show what the "fsys_resmgr" threads in devb are doing?

David

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http://community.qnx.com/sf/go/post82603

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