On large systems with many users, you need to control the amount of disk space a user has access to. Disk quotas are designed specifically for this purpose. Quotas, managed per each partition, can be set for both individual users as well as groups; quotas for the group need not be as large as the aggregate quotas for the individuals in the groups.
When files are created, both a user and a group own them; ownership of the files is always part of the metadata about the files. This makes quotas based on both users and groups easy to manage.
Everybody who owns a computer will someday need to dispose of a disk drive. Before you do, it is a good idea to cleanse the drive, so no one can read your sensitive information. Deleting files and reformatting is not sufficient; determined effort can still reveal data from a drive even after it appears to be gone. To do a more thorough job, I suggest using wipe.
Many people leave their computers on around the clock. This usually implies that all the attached hard disks are always spinning. Constantly spinning up a hard disk normally increases the chances of drive failure. When a disk is not powered it should last longer than if it was spinning.
So you just bought an external hard drive for backups. Now, with what filesystem should you format it? Ext2? FAT32? No matter which one you choose, there are trade-offs to consider.
TrueCrypt is a well known and trusted open source application for encryption. It allows you to create and manage an encrypted volumes that can be used seamlessly and transparently.
Introduced in Ubuntu 7.10 was install-time encryption support where using the alternate installer one can fully encrypt their disk in an LVM using dm-crypt. Unfortunately, the Ubiquity installer in Ubuntu 8.04 continues to lack LVM and encryption support, but using Ubuntu 8.04 Alpha 6 we have looked at the performance cost of this encrypted configuration on Ubuntu Linux. Rather than looking directly at the disk read/write overhead caused by the encryption process, we have provided some benchmarks to see how the real-world performance is impacted in both gaming and other desktop tasks.
Most users know about proprietary software packages such as Norton Ghost that can be used for cloning hard disks for backup or distribution purposes. And a few may know about Partition Image, an open source alternative for saving partition images. But how many users know about Clonezilla, an all-in-one cloning tool that promises both speed and power?
If you have been using Ubuntu for a while, you probably know that after 30 boots Ubuntu runs a check on the hard disk. This “Fsck” check slows down booting a lot. AutoFsck runs the check on shutdown instead, and asks you if it is a good time first. If the occasional slow boot is a problem for you, AutoFsck is perfect.
Disk failure, on the hardware side, is too broad to cover in any great detail here, but the following basic steps should be followed (of course, as noted, your setup may require otherwise). The scenario here is that one of your disks has just gone "bad." It's beyond recovery.
It is quite simple to set up encrypted volumes using truecrypt. If you mount the encrypted disks at boot time, then an annoyance is having truecrypt prompt for password or path to key for each disk. You can specify these things on the command line while mounting the encrypted volumes, but for a very large reasons that is not a clever approach.
If you want to Mount NTFS VMware Virtual Disk Image (vmdk) read/write follow this procedure. Vmware server comes with a little utility to mount the VMware virtual file systems called vmware-mount.pl. This utility works pretty well but mounts all NTFS partitions as Read Only!
I finally encrypted some partitions of my hard drive. An external hard drive that I just bought (320 Mb) allowed me to back up my entire /home partition and consider encrypting it. I mainly used this tutorial, but I derived a little from it about the unlocking system : I did not want to input a password while the machine boots, I wanted it to be transparent while I log in. This how to provides more complete information, if needed.