Difference between revisions of "File system"
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== Snapshots == | |||
Note that within your homedirectory, several states of your system | |||
at particular points in time, termed ''[http://en.wikipedia.org/wiki/Snapshot_(computer_storage) snapshots]'', are available. | |||
In case you deleted or overwrote files accidentally, this comes in handy and can be used | |||
to restore the respective files as they appeared in previous ''versions''. However, note | |||
that the term ''version'' is not fully correct: actually, the appearance of the files | |||
at previous ''times'' is stored and the available snapshots can be distinguished by means | |||
of their ''time-stamps''. As a technical aside and from a more coarse grained | |||
point of view, note that a snapshot is not a | |||
full copy of your full data. Instead, from one snapshot to the next (in time), it is | |||
amended by the changes you make in bit-by-bit fashion. | |||
The folder that contains your particular snapshots is located in your homedirectory. It | |||
is a ''hidden'' directory that is also '''not''' visible if you list the content of your | |||
homedirectory via <tt>ls -la </tt>. | |||
To make this as explicit as possible, to enter the respective hidden directory I | |||
type within my homedirectory | |||
alxo9476@hero01:~$ cd .snapshot | |||
Now, within that directory I find | |||
<nowiki> | |||
alxo9476@hero01:~/.snapshot$ ls | |||
hpc_user_daily_2013-06-28_01-00 | |||
hpc_user_daily_2013-06-29_01-00 | |||
hpc_user_daily_2013-06-30_01-00 | |||
hpc_user_daily_2013-07-01_01-00 | |||
hpc_user_daily_2013-07-02_01-00 | |||
hpc_user_daily_2013-07-03_01-00 | |||
hpc_user_daily_2013-07-04_01-00 | |||
hpc_user_daily_recent | |||
hpc_user_hourly_2013-07-03_20-00 | |||
hpc_user_hourly_2013-07-04_00-00 | |||
hpc_user_hourly_2013-07-04_04-00 | |||
hpc_user_hourly_2013-07-04_08-00 | |||
hpc_user_hourly_2013-07-04_12-00 | |||
hpc_user_hourly_2013-07-04_16-00 | |||
hpc_user_hourly_recent | |||
hpc_user_weekly_2013-06-10_02-00 | |||
hpc_user_weekly_2013-06-17_02-00 | |||
hpc_user_weekly_2013-06-24_02-00 | |||
hpc_user_weekly_2013-07-01_02-00 | |||
hpc_user_weekly_recent | |||
</nowiki> | |||
I.e., snapshots of my homedirectory distinguished by the precise points in | |||
time where they where taken. Within these folders you find the same | |||
file-structure as in your homedirectory, of course! | |||
Revision as of 17:18, 4 July 2013
Snapshots
Note that within your homedirectory, several states of your system at particular points in time, termed snapshots, are available. In case you deleted or overwrote files accidentally, this comes in handy and can be used to restore the respective files as they appeared in previous versions. However, note that the term version is not fully correct: actually, the appearance of the files at previous times is stored and the available snapshots can be distinguished by means of their time-stamps. As a technical aside and from a more coarse grained point of view, note that a snapshot is not a full copy of your full data. Instead, from one snapshot to the next (in time), it is amended by the changes you make in bit-by-bit fashion.
The folder that contains your particular snapshots is located in your homedirectory. It is a hidden directory that is also not visible if you list the content of your homedirectory via ls -la . To make this as explicit as possible, to enter the respective hidden directory I type within my homedirectory
alxo9476@hero01:~$ cd .snapshot
Now, within that directory I find
alxo9476@hero01:~/.snapshot$ ls hpc_user_daily_2013-06-28_01-00 hpc_user_daily_2013-06-29_01-00 hpc_user_daily_2013-06-30_01-00 hpc_user_daily_2013-07-01_01-00 hpc_user_daily_2013-07-02_01-00 hpc_user_daily_2013-07-03_01-00 hpc_user_daily_2013-07-04_01-00 hpc_user_daily_recent hpc_user_hourly_2013-07-03_20-00 hpc_user_hourly_2013-07-04_00-00 hpc_user_hourly_2013-07-04_04-00 hpc_user_hourly_2013-07-04_08-00 hpc_user_hourly_2013-07-04_12-00 hpc_user_hourly_2013-07-04_16-00 hpc_user_hourly_recent hpc_user_weekly_2013-06-10_02-00 hpc_user_weekly_2013-06-17_02-00 hpc_user_weekly_2013-06-24_02-00 hpc_user_weekly_2013-07-01_02-00 hpc_user_weekly_recent
I.e., snapshots of my homedirectory distinguished by the precise points in time where they where taken. Within these folders you find the same file-structure as in your homedirectory, of course!
