Debian/Apt and disk space

For a few days I was getting the following error when trying to do an apt-get update on my Debian/Stretch machine

~$ sudo apt-get update
Get:1 http://mirror.csclub.uwaterloo.ca stretch InRelease [200 kB]
Ign http://mirror.csclub.uwaterloo.ca stretch InRelease                       
Ign http://mirror.csclub.uwaterloo.ca stretch Release.gpg                     
Get:2 http://security.debian.org stretch/updates InRelease [62.8 kB]
Ign http://security.debian.org stretch/updates InRelease
Ign http://security.debian.org stretch/updates Release.gpg
Ign http://security.debian.org stretch/updates Release
Get:3 http://security.debian.org stretch/updates/main i386 Packages/DiffIndex [1,554 B]
Ign http://security.debian.org stretch/updates/main i386 Packages/DiffIndex
Get:4 http://security.debian.org stretch/updates/main Translation-en [14 B]
Get:5 http://security.debian.org stretch/updates/main i386 Packages [32 B]
Get:6 http://security.debian.org stretch/updates/main i386 Packages [32 B]
Ign http://security.debian.org stretch/updates/main Translation-en_CA
Ign http://security.debian.org stretch/updates/main Translation-en
Err http://security.debian.org stretch/updates/main i386 Packages
  404  Not Found [IP: 128.31.0.63 80]
Hit http://mirror.csclub.uwaterloo.ca stretch Release
Get:7 http://mirror.csclub.uwaterloo.ca stretch/main i386 Packages/DiffIndex [16.6 kB]
Ign http://mirror.csclub.uwaterloo.ca stretch/main i386 Packages/DiffIndex
Get:8 http://mirror.csclub.uwaterloo.ca stretch/main Translation-en [4,902 kB]
Get:9 http://mirror.csclub.uwaterloo.ca stretch/main i386 Packages [7,440 kB]
Get:10 http://mirror.csclub.uwaterloo.ca stretch/main i386 Packages [7,440 kB]
Err http://mirror.csclub.uwaterloo.ca stretch/main Translation-en_CA
  Bad header line [IP: 129.97.134.71 80]
Err http://mirror.csclub.uwaterloo.ca stretch/main Translation-en
  Bad header line [IP: 129.97.134.71 80]
Err http://mirror.csclub.uwaterloo.ca stretch/main i386 Packages
  Bad header line [IP: 129.97.134.71 80]
W: Failed to fetch http://security.debian.org/dists/stretch/updates/main/binary-i386/Packages  404  Not Found [IP: 128.31.0.63 80]

W: Failed to fetch http://mirror.csclub.uwaterloo.ca/debian/dists/stretch/main/i18n/Translation-en_CA  Bad header line [IP: 129.97.134.71 80]

W: Failed to fetch http://mirror.csclub.uwaterloo.ca/debian/dists/stretch/main/i18n/Translation-en  Bad header line [IP: 129.97.134.71 80]

W: Failed to fetch http://mirror.csclub.uwaterloo.ca/debian/dists/stretch/main/binary-i386/Packages  Bad header line [IP: 129.97.134.71 80]

E: Some index files failed to download. They have been ignored, or old ones used instead.

Trying to rule out problems due to network, I verified the the URL giving the error 404 in the browser and it worked fine. Then I checked my disk space as it was usually the culprit before I rebuilt the OS on a 80GB HDD (earlier the OS was in 4GB!). The /var partition was indeed used 100%. Applying the usual trick of apt-get clean did release much space!

On closer investigation, I noticed the kern.log and syslog files in /var/log/ were huge (kern.log 3.6GB, syslog 248 MB). The kern.log and syslog had error/warning splattered repeatedly such as:
Dec  1 07:36:00 imlee kernel: [1155666.501321] nouveau E[  PGRAPH][0000:01:00.0]  NOTIFY nsource: STATE_INVALID nstatus: INVALID_STATE BAD_ARGUMENT

Reducing the size of kern.log/syslog to 0 fixed the apt-get issue!The Debian/Stretch machine is uptodate again.