在 Cydia 上搜索应用进行安装，提示错误：failed to write (No space left on device)，从字面上的意思看是磁盘空间不够，导致写入错误，但是到 “关于” 里看到磁盘可用空间还剩 8.3G。尝试将 deb 包上传到手机，使用命令手动安装，还是提示相应的错误，信息如下：
# dpkg -i eXfaker.deb Selecting previously unselected package net.exchen.exfaker. (Reading database ... 4236 files and directories currently installed.) Preparing to unpack eXfaker.deb ... Unpacking net.exchen.exfaker (1.2.5) ... dpkg: error processing archive eXfaker.deb (--install): cannot copy extracted data for './Applications/eXfaker.app/eXfaker' to '/Applications/eXfaker.app/eXfaker.dpkg-new': failed to write (No space left on device) dpkg-deb: error: subprocess paste was killed by signal (Broken pipe: 13) Errors were encountered while processing: eXfaker.deb
使用 df -h 命令查看磁盘的情况，发现原来文件系统 /dev/disk0s1s1 的挂载点是 / 目录，可用空间果然是没有了，而 /dev/disk0s1s2 的挂载点是 /private/var 目录，可用空间还剩 8.3 G，信息如下：
# df -h Filesystem Size Used Avail Use% Mounted on /dev/disk0s1s1 2.6G 2.6G 0 100% / devfs 28K 28K 0 100% /dev /dev/disk0s1s2 13G 4.0G 8.3G 33% /private/var /dev/disk1 242M 72M 170M 30% /Developer
尝试卸载掉 /Applications 目录的一个应用，发现 / 目录的可用空间多了 6.1MB，再次使用 dpkg -i eXfaker.deb 命令安装应用就没问题了，信息如下：
# dpkg -i eXfaker.deb Selecting previously deselected package net.exchen.exfaker. (Reading database ... 2307 files and directories currently installed.) Unpacking net.exchen.exfaker (from eXfaker.deb) ... Setting up net.exchen.exfaker (1.2.5) ... # uicache
原文地址：https://www.exchen.net/ios-hacker-no-space-left-on-device.html