# [SOLVED]File size limit exceeded;using dd to backup over nfs

## pdunnavant

I'm having a few issues here... hopefully someone has some advice.   :Smile: 

The hard drive on my laptop is in the process of quickly biting the dust.  In fact, it's no longer bootable at the moment.  I have a replacement on the way, but I'd like to take a backup of it if possible.  Since it isn't bootable, I downloaded the minimal gentoo iso live cd so I could boot from that.  I have a 60 gig hard drive, and /dev/hda3 is the root partition that I'd like to take a backup of.  The fs is reiserfs, but it will not mount because of too many drive errors (about 107 bad blocks as of the last time I ran badblocks).

Anyway, that's not the issue I was writing about... what I'm having a problem with is the dd command.  I mounted another drive from another computer over NFS so that I could use dd to image /dev/hda3 to it.  The issue that I'm having is that when the image reaches 2 GB, dd errors out with the message "File size limit exceeded".  I've read several threads on the forum relating to this, but none seemed to apply to this particular case.  The nfs mounted drive is also using reiserfs.  ulimit -a shows that file size can be unlimited (on both machines).  The dd command I'm using is pretty simple:

```
# dd if=/dev/hda3 of=/mnt/gentoo/laptop.backup/backup conv=notrunc,noerror
```

I'm trying this on a different box now to see if that makes a difference, but it's pretty much the same setup, so I'm not too optimistic about the results being any different than they were on the other box.

Any suggestions?Last edited by pdunnavant on Mon Mar 05, 2007 9:24 pm; edited 1 time in total

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## pdunnavant

Ok, well, my attempt to the other box failed as well.  However, this time I got the "File size limit exceeded" message at 1.5 GB... interesting.  That makes me think that it's more likely an issue with the box on the receiving end of the file.  I still can't seem to figure out what the problem is.  I've read in several places that there may be a setting in /etc/security/limits.conf, but both my boxes only have comments in that file.  Most of the other similar issues I see have to do with using samba, so that doesn't really apply here.  Meh.  I'll see if I can figure out any more info tomorrow.

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## embobo

What version of NFS are you using? NFS v2 has a 2G file size limit.

If you can't use NFS v3 You might try something like

```

dd if=/dev/hda of= | split -b 1000m

```

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## pdunnavant

Ahhh...  heh.  Here I was assuming that I was using NFS v3 all along.    :Embarassed: 

Looks like the live cd already has v3 enabled in the kernel, so I went to my NFS'd box and added NFS v3 support to the kernel.  After a recompile and reboot, things now look like they're working ok.  dd has so far created a 35GB image of my laptop hard drive over the NFS share.

Thanks for your help.

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## embobo

I would also suggest using dd-rescue instead of dd. It will be faster and get as much data as possible from the drive. Also, make sure DMA is turned on for the drive. I don't know if the Gentoo Live CD turns that on.

http://www.gnu.org/software/ddrescue/ddrescue.html

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## pdunnavant

 *embobo wrote:*   

> I would also suggest using dd-rescue instead of dd.

 

I was going to attempt to use dd-rescue, but it doesn't look like that is included on the Gentoo minimal live cd.  It may be on the universal cd, but I didn't try to get a copy of that.  Maybe I'll try that, too.

Thanks!

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