Filesystem details

This page gives details of available data storage spaces, with an emphasis on scientific computing access on Linux.

Other operating systems: Windows and OSX workstations do not currently have any of these paths mounted. In the future, project and archive may be automatically mounted. You can always remote mount via sshfs or SMB. See the remote access page for Linux, Mac, and Windows instructions for home,project, and archive. In OSX, there is a shortcut in the launcher for mounting home. In Windows workstations, this is Z drive. On your own computers, you may need to use AALTO\username as your username for any of the SMB mounts.

Laptops: Laptops have their own filesystems, including home directories. These are not backed up automatically. Other directories can be mounted as described on the remote access page.

Summary table

This table lists all available options in Science-IT departments, including those not managed by departments. In general, project is for most research data that requires good backups. For big data, use scratch. Request separate projects when needed to keep things organized.INLINE


Path (Linux)






/u/…/$user name/unix


100 GiB

yes, $HOME/../.sn apshot/

Used for personal and non-research files


/m/$dept/proj ect/$project/


per-project, up to 100s of GiB

Yes, hourly/daily /weekly. (.snapshot)


/m/$dept/arch ive/ $project/


per-project, up to 100s of GiB

Yes, hourly/daily weekly. + off-site tape backups. (.snapshot)


/m/$dept/scr atch/$pro hect/


per-project, 2 PiB available

RAID6, but no backups.

Don’t even think about leaving irreplaceable files here! Need Triton account.

work (Triton)

/m/$dept/wor k/$username/


200 GB default

RAID6, but no backups.

Same as scratch. Need Triton account.


/l/$username /


usually a few 100s GiB available

No, and destroyed if computer reinstalled.

Directory needs to be created and permissions should be made reasonable (quite likely ‘chmod 700 /l/$USER’, by default has read access for everyone!)

Space usage: `du -sh /l/`. Not shared among computers.


/run/user/$u id/


local memory


Not shared.


$HOME/public _html/

(/m/webhome/ …)


5 GiB

https://use ~USER/

custom solutions

Contact us for special needs, like sensitive data, etc.

General notes

  • The table below details the types of filesystems available.

  • The path /m/$dept/ is designed to be a standard location for mounts. In particular, this is shared with Triton.

  • The server magi is and is for the CS department. Home directory is mounted here without kerberos protection but directories under /m/ need active kerberos ticket (that can be acquired with ‘kinit’ command) . taltta is and is for all Aalto staff. Both use normal Aalto credentials.

  • Common problem: The Triton scratch/work directories are automounted. If you don’t see it, enter the full name then tab complete and it will appear. It will appear after you try accessing with the full name.

  • Common problem: These filesystems are protected with Kerberos, which means that you must be authenticated with Kerberos tickets to access them. This normally happens automatically, but they expire after some time. If you are using systems remotely (the shell servers) or have stuff running in the background, this may become a problem. To solve, run kinit and it will refresh your tickets..


  • home: your home directory

    • Shared with the Aalto environment, for example regular Aalto workstations, Aalto shell servers, etc.

    • Should not be used for research work, personal files only. Files are lost once you leave the university.

      • Instead, use project for research files, so they are accessible to others after you leave.

    • Quota 100 GiB.

    • Backups recoverable by $HOME/../.snapshot/ (on linux workstations at least).

    • SMB mounting: smb://

  • project: main place for shared, backed-up project files

    • /m/$dept/project/$project/

    • Research time storage for data that requires backup. Good for e.g. code, articles, other important data. Generally for small amount (10s-100s GiB) of data per project.

    • This is the normal place for day to day working files which need backing up.

    • Multi user, per-group.

    • Quotas: from 10s to 100s of GiB

    • Quotas are not designed to hold extremely large research data (TiBs). Ideal case would be 10s of GiB, and then bulk intermediate files on scratch.

    • Weekly backup to tape (to recover from major failure) + snapshots (recover accidentally deleted files). Snapshots go back:

      • hourly last 26 working hours (8-20)

      • daily last 14 days

      • weekly last 10 weeks

      • Can be recovered using .snapshot/ within project directories

    • Accessible on magi/taltta at the same path.

    • SMB mounting: smb://$group/

  • archive:

    • /m/$dept/archive/$project/

    • For data that should be kept accessible for 1-5 years after the project has ended. Alternatively a good place to store a copy of a large original data (backup).

    • This is practically the same as project, but retains snapshots for longer so that data is ensured to be written to tape backups.

    • This is a disk system, so does have reasonable performance. (Actually, same system as project, but separation makes for easier management).

    • Quotas: 10s to 1000s of GiB

    • Backups: same as project.

    • Accessible on magi/taltta at the same path.

    • SMB mounting: smb://$group/

  • scratch: large file storage and work, not backed up (Triton).

    • /m/$dept/scratch/$group/

    • Research time storage for data that does not require backup. Good for temporary files and large data sets where the backup of original copy is somewhere else (e.g. archive).

    • This is for massive, high performance file storage. Large reads are extremely fast (1+ GB/s).

    • This is a lustre file system as part of triton (which is in Keilaniemi).

    • Quotas: 10s to 100s of TiB. The university has 2 PB available total.

    • In order to use this, you must have a triton account. If you don’t, you get “input/output error” which is extremely confusing.

    • On workstations, this is mounted via NFS (and accessing it transfers data from Keilaniemi on each access), so it is not fast on workstations, just large file storage. For high performance operations, work on triton and use the workstation mount for convenience when visualizing.

    • This is RAID6, so is pretty well protected against single disk failures, but not backed up at all. It is possible that all data could be lost. Don’t even think about leaving irreplaceable files here. CSC actually had a problem in 2016 that resulted in data loss. It is extremely rare (decades) thing, but it can happen. (still, it’s better than your laptop or a drive on your desk. Human error is the greatest risk here).

    • Accessible on magi/taltta at the same path.

    • SMB mounting: smb://$dept/$dir/. (Username may need to be AALTO\yourusername.)

  • Triton work: personal large file storage and work (Triton)

    • /m/$dept/work/$username/

    • This is the equivalent of scratch, but per-person. Data is lost once you leave.

    • Accessible on magi/taltta at the same path.

    • SMB mounting: smb://$username. (Username may need to be AALTO\yourusername.)

    • Deleted six months after your account expires.

    • Not to be confused with Aalto work (see below).

  • local: local disks for high performance

    • You can use local disks for day to day work. These are not redundant or backed up at all. Also, if your computer is reinstalled, all data is lost.

    • Performance is much higher than any of the other network filesystems, especially for small reads. Scratch+Triton is still faster for large reads.

    • If you use this, make sure you set UNIX permissions to restrict the data properly. Ask if you are not sure.

    • If you store sensitive data here, you are responsible for physical security of your machine (as in no one taking a hard drive). Unix permissions should protect most other cases.

    • When you are done with the computer, you are also responsible for secure management/wiping/cleanup of this data.

    • See the note about disk wiping under Aalto Linux (under “when you are done with your computer”). IT should do this, but if it’s important you must mention it, too.

  • tmpfs: in-memory filesystem

    • This is a filesystem that stores all data in memory. It is extremely high performance, but extremely temporary (lost on each reboot). Also shares RAM with your processes, so don’t use too much and clean up when done.

    • TODO: are these available everywhere?

  • webhome: web space for

    • This is the space for space can be accessed from the public_html link in your home directory.

    • This is not a real research filesystem, but convenient to note here.

    • Quota (2020) is 5 GiB. (/m/webhome/webhome/)


  • triton home: triton’s home directories

    • Not part of departments, but documented here for convenience

    • The home directory on Triton.

    • Backed up daily.

    • Not available on workstations.

    • Quota: 1 GB

    • Deleted six months after your account expires.

  • Aalto work: Aalto’s general storage space

    • /work/$deptcode on Aalto workstations and servers.

    • Not often used within Science-IT departments: we use project and archive above, which are managed by us and practically equivalent. You could request space from here, but expect less personalized service.

    • Aalto home directories are actually here now.

    • You may request storage space from here, email the Aalto servicedesk and request space on work. The procedures are not very well established.

    • Data is snapshotted and backed up offsite for disaster recovery.

    • Search for “” for the latest instructions.

    • SMB mounting via smb://

  • Aalto teamwork: Aalto’s general storage space

    • Not used directly within Science-IT departments: we have our own direct interfaces to this, and project and archive directories are atually here.

    • For information on getting teamwork space (outside of Science-IT departments), contact servicedesk.

    • Teamwork is unique in that it is arbitrarily extensible, and you may buy the space from the vendor directly. Thus, you can use external grant money to buy storage space here.

    • SMB mounting via smb://