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Department of Computer Science

Technical Services and Support

Storage Technology Options

Storage Information on CS Linux Systems

This page describes various storage provided by LCSR, which you can use. However you can use the same technology to set up your own file servers, or to allow files on your server or desktop to be available from other systems.

Note that LCSR is moving in the direction of a few file servers, all accessible from all systems that participate in the LCSR Kerberos system. This includes generally-available systems such as iLab systems, but also most research systems.

Note: Our machines use auto mount which means the file system is mounted as you access it. To access non mounted file system, simply just access it. Example to access /common/users/$USER you simply type: cd /common/users/$USER

CS Storage Summary
CS Storage Summary
StorageTypeBacked up

Disk Quota

Student/PhD, Faculty

/common/home/ SSD Yes 50GB / 200GB
/common/users/ SSD Yes 100GB / 1TB
/fac/users/ SSD Yes100GB (Faculty only)
 /freespace/local SSD No None
 /filer/tmp1 SSD No None
 /research/projects/{projectName} Non SSD Yes project specific
 /research/archive Non SSD Yes None

Most systems in computer science have access to the following:

  • Home directories [/common/home] for general-access systems and are hosted in a SSD (actually NVMe) based file server  with 40 Gbps networking.  This is intended for projects that need high performance.
    Quota: 50 GB for most students, 200 GB for faculty and PhD students and [/fac/users] home directory has 100 GB of quota.
  • /common/users/$USER. Can be used to supplement your home directory if you need more space. Traditional storage. Quota: 100 GB for most students, 1TB for PhD students and Faculty.
  • /filer/tmp1 – intended as working space if you need more storage for a short period. SSD storage and no quota, but not backed up, and will be cleared if it fills, and may be cleared at the beginning of every semester and summer.
  • Local storage, normally on /freespace/local. This is SSD storage (i.e. fairly fast), but it is not backed up, and may be cleared out when it fills and between semester. This is intended for short-term working storage.
  • /research/archive. For data that funding agencies require to be kept. This will eventually be merged with /common/users into a single system for files that don’t need SSD. Please contact us, if you need this service.

Essentially, /common/home is the primary storage for all users including research, with /common/users for files not currently being used heavily. /common/home has fast disks. /common/users will be larger capacity, but with traditional disks.


Technology We use

The underlying approach we use is NFS, a Network File System that is supported for Unix and Linux, and to some extent also MacOS and Windows. Specifically, we use NFS version 4 with Kerberos authentication. Version 4 with Kerberos allows incorporation of systems run by different system administrators, which may not always have consistent UID and GIDs, and may have varying levels of security.

We also recommend setting up the /net virtual file system. That allows you to access files on any system that permits it, without having to get your system administrator to add a mount. Thus is provides the illusion that file systems on all of our servers are part of a single, combined name space.

Systems run by LCSR already have the necessary software. For information on integrating your systems into our Kerberos infrastructure, see Setting up Kerberos and Related Services.

Running out of space?

To find out how much disk quota is available for you, see Summary section below.  To see how much space are used for each available filesystem,

  • open a terminal window or connect via ssh client and
  • type: quota -vs and you will see something similar to below

If you run out of disk space in your home directory (User home directory is /common/home), you current usage will be closed to your quota.

To find out where your disk space went type: du -a ~ | sort -rn | more This command will give your a list of total space used for each directory you own with most usage listed on top.

Most common cases, the hidden .cache, .trashcan or .local directory is growing out of bound and needs to be cleaned up or you forgot to empty your Trash.

If you run out of space in your home directory, please utilize  /freespace/local, /common/users/your_netid  storage described in section B and C below.

Storage available with Computer Science

A.Home Directories

Users’ home directories on our generally-available systems are located on the LCSR machines named communis.lcsr. For Quota info, see Summary section above. Each machine in its cluster share the same home directory storage and accessible at:

  • /common/home for iLab and general research machines.
  • /fac/users for Faculty machines.

These directories are backed up and lost files are recoverable. Essentially, we keep backups for up to two months and have a fall back position in case of hardware failure.)

Accounts are given home directory quota limits in order to share this very expensive resource. Should you find your initial quota too small, you should consider other shared disks like /common/users, /filer/tmp and /freespace/local below. If there are justifiable reasons, you can request additional space (please give an estimate of how much more you need, how long you believe you will need it and a short justification of what you need it for). 

B. Shared Local Filesystems
  • /freespace/local (available only on iLab/Grad/Fac desktops machines)
    Most machines have some extra non quota disk space set aside in a partition called/freespace/local. You should note that these filesystems restrictions below.
    – Files are not backed up
    – This storage has has no quota but limited to available space available.
    – Files in /freespace/local are automatically deleted when machines are re-installed  without prior warning.
    – All files may be removed between end and start of a semester or when we run out of space without prior warning.
  • /ssd/local (available on iLabU machines only) has the same policy as /freespace/local above.
C. Computer Science Remote Filesystems
  • /common/home
    – This is the default home directory for iLab and general CBIM machines.
    – Quotas 50 GB for most users and  200 GB for faculty/PhD students.
    – Based on a Linux file server using the ZFS file system, and NVMe storage.
    – It is backed up daily. There are daily snapshots, kept for 59 days. These can be used to recover files that were accidentally deleted.
    – Researchers may request special project directories.
  • /common/users
    – There is a 100 GB quota limit. 1TB for PhD students and Faculty.
    – Can be accessed in /common/users/your_netid or /common/users/$USER
    – It is accessible from all systems that participate in LCSR’s Kerberos, i.e. the general-access systems and most research systems.
    – This file system has a single daily backup and there is no snapshot.
  • /fac/users
    – There is a 100 GB quota limit for Faculty use only.
    – Can be accessed in /fac/users/your_netid or /fac/users/$USER
    – It is accessible from faculty systems that participate in LCSR’s Kerberos only.
  • /filer/tmp1
    LCSR has a raided (so any single disk failure will not cause data loss) filer with about 7.5 TB space available on it. The filesystems are:
    –  accessible from all generally-available systems. This uses SSD storage.
    –  has has no quota but limited to available space available.
    –  is not backed up.
    – is not intended to be permanent storage.
    is cleared when filled, and may be cleared at the beginning of every semester and summer.
D. Special Storage For Projects
  • Project space on our filesystems
    Larger amounts of space can be arranged for individuals or groups needing aggressively backed up space. This space is generally subject to the same policy as our home directories. (Essentially, we keep backups for up to two months and have a fall back position in case of hardware failure.) This space must be requested by the DCS faculty member working on the project to storage-technology via CS HelpDesk. 
  • Petabyte filers
    CBIM currently has two 1 PB file servers, but reasonable amounts of space are available for other CS users. 
E. Cloud Storage
  • Dropbox – Not supported. Use Scarletmail Google Drive. You have 30GB of storage space there instead of 2GB.
  • Google Drive.
    University has made an arrangement for an 30Gb of disk space for Google Drive under the Scarlet Apps system. All CS Linux machines can be linked to Google Drive.  Please see Connecting Google Drive with CS Linux Machines. Note that this can only be used if you are using Gnome graphical interface locally or via Microsoft Remote Desktop client. This does not work if you access via ssh or X2Go client. Alternatively, you can use rclone(cmd line) or rclone-browserGUI) by following for configuration.
    To start rclone-browser, follow:
    export TERMINAL=/usr/bin/xfce4-terminal

    Note: if you setup mount points, make sure you set it at  /tmp/mountPointName, where mountPointName is a name of your choosing. Example: your_netid-gdrive
    The University has  arranged an 1TB capacity contract with  To acess, please use rclone(cmd line) or rclone-browserGUI) by following for configuration.
    To start rclone-browser, follow:
    export TERMINAL=/usr/bin/xfce4-terminal

    Note: if you setup mount points, make sure you set it at  /tmp/mountPointName, where mountPointName is a name of your choosing. Example: your_netid-box
  • If there are other cloud services you want to access, contact us. There are tools available for many services, but many of them aren’t things we’d want to make generally available.
  • If you are using VMs or storage in Amazon or similar environments, we’re willing to look at setting up links from systems here to them. There are Linux tools to access Amazon file systems and their competitors.
F. Other StorageAvailable

If you maintain your own disk space you would like to access them from our machines or want to access our file systems from home computers, below are a few options.

  • shfs
    LCSR has installed sshfs on our primary clusters. You can also install it on system you run, as well as home systems. sshfs allows you to mount file systems to which you have access on any computer where you can login via ssh. Performance is at least as good as an NFS mount, and often better. In most cases this is a better option than WebDAV. For details, see accessing files remotely.
  • /net/yourhost/… 
    On the faculty and research machines, we have enabled /net automounting. So if your hostname is “myhost”, and you NFS export the filesystem “/my/directory/” to the faculty or research machines, you will be able to automount your files by connecting to “/net/myhost/my/directory”.  See sharing files for more details.
  • See our how to page to learn more about available File Sharing options.

For help with our systems or If you need immediate assistant, visit LCSR Operator at CoRE 235 or call 848-445-2443. Otherwise, see CS HelpDesk. Don’t forget to include your NetID along with descriptions of your problem.