Types of Backup at ICS

Snapshots

A Snapshot copy is a read-only image of a disk or volume that captures the state of the file system at a point in time. We can think of these snapshots as “back up” copies. Most ICS Network File Servers (NFS) and Samba servers maintain regular snapshots for /home and /extra directories. The snapshot schedule and availability differ from device to device and volume to volume, but most commonly 30 daily snapshots are kept.

Tardigrade Purestorage Flashblade

Most home and extra directories are store on Tardigrade. Snapshots are available on most filesystems. Typically, snapshots are taken daily and retained for 28 days. Occasionally, when significant changes are made to the filesystem, it is necessary to delete snapshots early.

Snapshots are read-only and they do not contribute to quota'd disk usage.

How to use Snapshots to Recover Files

For Linux systems, cd into the hidden directory:

  • ~/.snapshot

On Windows 10, use the following on This PC's address bar:

  • H:\.snapshot where H is the drive letter for samba drives, like your home directory
  • S:\.snapshot where S is the drive letter for samba shared drives

If the above does not work for you, try mapping the snapshot folder directly:

  • Right click on This PC (Windows 10)
  • Select Map Network Drive or go to the Computer tab and select Map Network Drive
  • For Drive, choose an available drive letter
  • For Folder, use:
    \\samba.ics.uci.edu\youICSusername\.snapshot

From MacOs, assuming you have your home directory mounted as follows:

  • smb://samba.ics.uci.edu/youICSusername

You will repeat the mapping steps (Finder, Go, Connect to Server) with:

  • smb://samba.ics.uci.edu/youICSusername/.snapshot

Network Appliance

Most home directories and some extra directories are stored on Cyberton. Snapshots are available on most volumes. Typical snapshot policy is for 28 daily snapshots and 2 hourly snapshots. Some volumes that see frequent or large changes in content will have fewer snapshots available. Snapshots are read-only and do not contribute to your overall disk usage. These are provide for you to self-restore files you have accidentally overwritten or deleted.

How to Recover Files

For Linux systems, use:

  • the hidden directory ~/.snapshot

On Windows 10, use the following on This PC:

  • H:\~snapshot where H is the drive letter for cybertron drives, like your home directory
  • S:\.snapshot where S is the drive letter for samba shared drives

The .snapshot directory is hidden and will not be visible in the file explorer so you will press the Windows key and type in the drive letter and path (e.g. H:\.snapshot).

Alternatively, the full path may be entered into the file explorer's navigation bar: where you would press Enter, look at the right pane, and navigate the folder structure until you find files you want to retrieve. Please note that these backup folders are organized by date and time. Once you find those files, copy them to another location.

ZFS NFS Appliances

Most ZFS NFS appliances keep 14 daily snapshots and 2 weekly snapshots.

These are user accessible via the /net automount path:

/net/<hostname>/<volume>/.zfs

You can determine the hostname and volume name using the ldapsearch command:

ldapsearch -x cn=hans1 nismapentry    
dn: cn=hans1,nismapname=auto_extra.byname,dc=ics,dc=uci,dc=edu
nismapentry: b4.ics.uci.edu:/b4_ics_tank/hans1

In this example, snapshots would be available at:

/net/b4.ics.uci.edu/v4_ics_tank/.zfs

Long Term Backup

In addition to nightly snapshots, most storage space also gets backed up to tape. The software that we utilize is Spectrum Protect. Most spaces get backed up monthly.

Retention Period

Any data that gets backed up to tape will be kept for a maximum of two years.

What gets backed up?

Everything in your /home or /extra gets backed up. Some research space may have a different policy. Please check with your group or contact Helpdesk for details.

Not Backed Up Items

  • .snapshots folder
  • scratch folder
    • The folder can be located at any level. Any data you place in there will not be backed up. This is great if you are writing large amount of temporary data as it greatly reduce the burden on resources.
  • Files with extension *.vdi
accounts/snapshots.txt · Last modified: 2022/04/26 09:38 by luciad
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