執行yum update時提示空間不足，目前見到了2種:
1.我升級過程中遇到的問題，提示如下：
Transaction Check Error:
  installing package kernel-PAE-2.6.34.7-61.fc13.i686 needs 6MB on the /boot filesystem

Error Summary
-------------
Disk Requirements:
  At least 6MB more space needed on the /boot filesystem.

出現此問題後用df檢視分割槽情況，結果如下：
[[email protected]

~]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2             3.9G  3.2G  466M  88% /
tmpfs                 502M   24K  502M   1% /dev/shm
/dev/sda1              49M   26M   21M  55% /boot
/dev/sda5              14G  1.1G   13G   8% /home 

解決方法：
(1)Remove old kernels. If you have multiple old kernels you're no longer using, you might be able to free up enough space to install the new one by uninstalling the very oldest kernel image. This will only work if you have 2 or more kernels installed, and assumes your system isn't actually using that oldest kernel image.

例項(http://www.itenter.com/operatingsystems/linux/2010/0811/5516.html)：
[[email protected] ~]$ uname -r    檢視現在所使用的kernel
2.6.33.6-147.2.4.fc13.i686.PAE
[[email protected] ~]$ rpm -qa | grep kernel   檢查系統中所存在的kernel
kernel-headers-2.6.33.6-147.2.4.fc13.i686
kernel-PAE-devel-2.6.33.6-147.2.4.fc13.i686
abrt-addon-kerneloops-1.1.1-2.fc13.i686
kernel-PAE-2.6.33.6-147.2.4.fc13.i686
kernel-2.6.33.6-147.2.4.fc13.i686
kernel-PAE-devel-2.6.33.6-147.fc13.i686
kernel-PAE-2.6.33.6-147.fc13.i686
kernel-2.6.33.6-147.fc13.i686
系統中有兩個版本的核心，分別是2.6.33.6-147和2.6.33.6-147.2.4。根據uname查詢結果可知現在147.2.4核心下，而且這個核心已經是新核心，所以我們刪除舊核心2.6.33.6-147。
[

[email protected] ~]$ su -c’yum remove kernel-2.6.33.6-147.fc13.i686 kernel-PAE-2.6.33.6-147.fc13.i686 kernel-PAE-devel-2.6.33.6-147.fc13.i686′
[[email protected] ~]$ reboot   重啟系統並檢查現在核心

實戰：
[[email protected] ~]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2             3.9G  3.2G  466M  88% /
tmpfs                 502M   24K  502M   1% /dev/shm
/dev/sda1              49M   26M   21M  55% /boot
/dev/sda5              14G  1.1G   13G   8% /home
[[email protected] ~]$ uname -r
2.6.33.3-85.fc13.i686.PAE
[[email protected] ~]$ rpm -qa | grep kernel
abrt-addon-kerneloops-1.1.0-1.fc13.i686
kernel-PAE-devel-2.6.33.3-85.fc13.i686
kernel-headers-2.6.33.3-85.fc13.i686
kernel-PAE-2.6.33.3-85.fc13.i686
沒有多個核心，所以沒法用刪除核心的方法了。不過可以試試刪除一個package看看效果。
[[email protected] bochs]# yum remove kernel-PAE-2.6.33.3-85.fc13.i686
[[email protected] bochs]# rpm -qa | grep kernel
abrt-addon-kerneloops-1.1.0-1.fc13.i686
kernel-PAE-devel-2.6.33.3-85.fc13.i686
kernel-headers-2.6.33.3-85.fc13.i686
[[email protected] bochs]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2             3.9G  3.1G  590M  85% /
tmpfs                 502M   24K  502M   1% /dev/shm
/dev/sda1              49M  5.4M   41M  12% /boot   //可用空間增大了
/dev/sda5              14G  1.1G   13G   8% /home

(2)Relocate /boot to the root partition. You could relocate /boot from its own partition to a directory on the root partition (/). I'm not sure of the process -- I'd assume this would get the basic setup going, but you'd need another command to update your bootloader (Grub?) and alert it to the new location.
These commands need root privs (use sudo with each, or get a root shell with su).

make the new location
mkdir /boot-new

copy boot files
( cd /boot ; tar cf - . ) | ( cd /boot-new ; tar xvf - )
(with sudo...)
sudo sh -c "( cd /boot ; tar cf - . ) | ( cd /boot-new ; tar xvf - )"

unmount separate partition -- maybe not doable without rebooting? maybe need to boot to a liveCD?
umount /boot

remove old boot directory, rename new
mv /boot /boot-old
mv /boot-new /boot

edit /etc/fstab, comment out /boot partition line or change mountpoint to /boot-old

missing step: reconfigure your bootloader to access /boot on /dev/sda7 instead of the old version on /dev/sda6.

(3)Resize your /boot partition. You'll need a LiveCD for the task. Boot into it and run gparted. You'll probably need to resize your system partition slightly, then move it, to make room. I can't give you specifics without knowing the partition table.

Expand the /boot partition to a size of at least 2-300MB to avoid having this problem again.

Resizing system partitions can be dangerous. Make backups before you attempt it, and read up on what you are doing before you do it. This is my least recommended option.

(4)Replace your system drive. Finally, if you've wanted a larger system hard drive, now is a great time to do so. In the process of copying partitions from the old drive to the new, you can expand the /boot partition. You'd use a LiveCD for this as well.
原文見：http://superuser.com/questions/82204/resizing-the-boot-partition

2.網上看到的問題，提示如下：
Insufficient space in download directory //var/cache/yum/updates/packages
解決方法：
(1)
For example if mounted partition /u has sufficient room,
cd /var/cache
find yum -print|cpio -pdmv /u
rm -rf yum
ln -s /u/yum yum

或者

yum clean all  清空一下快取
(2)
yum update 的軟體包，可以放在別的地方。即可。
修改/etc/yum.conf 裡面第一個就是下載包放的位置。我放在/home/XX/fc10 裡面。使用者備份。
[~ $] more /etc/yum.conf
1 [main]
2 #cachedir=/var/cache/yum
3 cachedir=/home/XX/fc10-yum