I am writing data munging scripts (python and bash), to munge data and import large quantities of text files into a database.
I am currently in the test phase, so I am generating several K's of files and deleting them (the files consume about 20G of space). After a test run, I delete the files (sometimes without having imported into the database).
I notice that there is a steady decrease in the amount of free space on my disk (as reported by
df -h). I don't understand this, as I use rm * (in the data directory), and in the cases where I use Nautilus, I empty the Trash bin as well.
Similarly, I notice that when I import the data into the (postgresql) database, and then delete the data from the tables using
DELETE FROM tablename;, the size consumed in the postgresql data directory does not go down either.
Currently, I have lost approximately 200G from hard drive, and I need to reclaim that - but don't know what to do to reclaim it - any ideas?.
I am running Ubuntu 10.0.4 LTS + postgresql 8.4
du -c / | 2>/dev/null | grep total produces this output:
4 /usr/src/linux-headers-2.6.32-38-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-41-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-36-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-30-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-35-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-31-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-27-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-28-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-40-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-34-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-37-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-33-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-39-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-29-generic/include/config/mtdram/total 4 /usr/src/linux-headers-2.6.32-32-generic/include/config/mtdram/total 187426036 total
df -hi produces this output:
Filesystem Inodes IUsed IFree IUse% Mounted on /dev/sda1 29M 1.8M 27M 7% / none 491K 776 490K 1% /dev none 492K 6 492K 1% /dev/shm none 492K 76 492K 1% /var/run none 492K 2 492K 1% /var/lock none 492K 1 492K 1% /lib/init/rw /dev/sdb1 30M 3.0K 30M 1% /mydata /dev/sdc1 0 0 0 - /media/Cruzer