Home Space
Each user account is given a home space for personal file storage located at
/mnt/home/$USER
, where $USER
is the environment
variable of the user's login name. Alternatively, it can be accessed at ~/
,
though this shorthand may not work in some scripts.
By default, it is only accessible to the user. It is often referred to as the “home
directory” since this is the beginning directory after login of any HPCC
node.
Every home space starts with a 50 GB limit for file storage space and can not contain more than 1 million files. To check the quota and used space of your home directory, see the Space quota section. You can request to increase your quota up to 1TB by completing Quota Increase Request form. Storage space greater than 1TB is available for an annual fee paid through a MSU financial account. Users can find the fee and submit their request by completing the Large Quota Increase Request form. If you would like to store more than 1 million files in your home space, please refer to the section Limit on number of files.
All home directories are stored in the IBM General Parallel File
System (GPFS). It is automatically backed up
except files saved in the nodr
space. To restore any file from backup,
please submit a ticket and let us know the paths to the files or the
directory with the time frame you would like them restored.
For the system security and user data privacy, we recommend that users do NOT open home directory access permission to others. When you report an issue about files saved in home, please attach them to your message for reference. ICER staff cannot access any files or directories in your home directory.
Warning
Currently our home file system check quota function will sometimes cause a user's directory over the quota due to incorrect calculation of used space. If you see this please open a ticket and we will work with you to temporarily increase your quota. We continue to work with our vendor to correct this issue.
Space quota
The only way to get quota information of home space is to run the
command quota
:
1 2 3 4 5 |
|
where all file spaces accessible to the user are listed, including home, research, and scratch. In each space, the information of quota, usage and availability on space size and number of files can be found. If "Free" or "Available" is a negative value (such as the "Space Available" column in the above example), the usage is over the quota, please remove, transfer or compress some files so the used space or the file count can be lower than the "Quota" value.
Actual disk usage (du
) different from quota results
The GPFS system set the smallest file block size to 64KiB. This means that files between 2KiB and 64KiB will occupy 64KiB of space. This causes space usage to be greatly inflated for users with large amounts of small files. One suggested solution would be to compress many small files into one large file (larger than 64KiB). In this way, the number of files can also be reduced. If you still have any difficulty, a temporarily larger quota can be requested if your quota is at 1TB with many small files.
Limit on number of files
Besides the quota on the size of space, users are also limited to 1 million files in their home or research directory. We need to set this limit because, with a great number of files, the file system will spend too much time on backups to be able to function normally. If possible, users can compress many files into one to reduce the file number.
If users do not wish to have the limit, they can request to have
a portion of their home quota (or research space) moved under nodr
space
(/mnt/ufs18/nodr/
or /mnt/ufs18/nodr/research/
) by submitting a
help ticket
with the drop-down subject 'other' and secondary subject 'nodr request'. There is no
limit on the file count, but there is no backup of these files either.
Users will be responsible for their own backup of files in the nodr
space.
By default, one half of the current home quota is assigned to the
requested nodr
space. The original quota under
/mnt/home/
(or /mnt/research/
) is then reduced to half the original quota so the
total space quota remains the same. A different size of nodr
space can
also be assigned based on the user's request. Once this space is
created, the path and the quota information on both home and nodr space
can be found using quota
command mentioned above.
Backups
All home space files are periodically, automatically backed up (except
those files that a user has opted to store in a specially requested
nodr
space). To access file backups, please submit a
help ticket
containing the file paths and the period, i.e. the time frame, from
which the files should be restored.