home overview news links contact search
 
 

Quota and Usage Statistics 

The USCMS Tier 1 Facility provides several file sytems for its users. These file sytems are configured in different ways for different purposes. Information is provided below on purpose and configuration differences, quota and usage statistics, instructions on how to check your quota and options available to you if you should run out of quota.

What is the maximum quota?

The rules are not entirely clear - the most stringent interpretation of them would say a user is allowed 1 TB/year combining the BlueArc+resilient+store/user file spaces. The most liberal interpretation is 1 TB/year in each. The LPC heads have decided to set a quota of 2 TB per user in each for now. All requests for space must be approved by Dan Green or Chris Tully.

BlueArc Space

/uscms 

Snapshots for /uscms are daily starting at 18:00 and kept for 4 days. (for details see Backup/SnapShot )
  Purpose: Home areas, area small quota, backed up to tape
  1. Stats sorted by usage
  2. Stats sorted by quota limit set
  3. Stats sorted by percentage of limit used

Data Areas

There are several data areas located on the BlueArc disk. The /uscms_data/d1 area is simply a collection of symbolic links that point to a user's actual data area (currently /uscms_data/d2 or /uscms_data/d3)
Its best if users use the /uscms_data/d1 path to access their data just in case the actual data area needs to be moved to a different file system for space reasons.

/uscms_data/d2

No tape backups
No snapshots

  Purpose: Data area with quotas (large for LPC groups), not backed up to tape
  1. Stats sorted by usage
  2. Stats sorted by quota limit set
  3. Stats sorted by percentage used

/uscms_data/d3

No tape backups
No snapshots

  Purpose: Data area with quotas (large for LPC groups), not backed up to tape
  1. Stats sorted by usage
  2. Stats sorted by quota limit set
  3. Stats sorted by percentage used

/uscmst1b_scratch/lpc1

No tape backups
No snapshots

  Purpose: Data area WITHOUT quota for LPC groups and for 3DayLifetime; not backed up in any fashion. Do not store unreproducible work in this area - there are NO BACKUPS. The 3DayLifetime area (/uscmst1b_scratch/lpc1/3DayLifetime) is accessible by ALL users. As the name suggests, files stored here are automatically removed after 3 days. Since there are no quotas on this file system we expect users to clean up their directories on a regular basis. If the file system begins to get full we will send out email to the users asking them to clean up their areas.
  1. Stats usage

dCache

  1. Resilient dcache usage
    2. The resilient space is meant for small (< 1GB) files or transient files.
  2. Store/user usage
    3. The store/user space is meant for more permanent files and is backed up to tape.
You will see on these pages the list of users flagged as being over quota. These users will get 1 automated email informing them they are over quota. Once you get that email, you'll need to request more quota from the CMS LPC heads. If we don't hear from them within 2 weeks, we will disable your write access.

Checking your quota usage on NFS mounted areas (Bluearc):

  Users can use the UNIX "quota" command to check their disk/quota usage. The output includes information on ALL nfs mounted file systems even those that may not have quotas set.
An example:  
<> quota -s
quota: Error while getting quota from cmspnfs:/cms for 1291: Invalid argument
quota: Error while getting quota from cmsstor37:/uscmst1/prod for 1291: Invalidargument
Disk quotas for user lisa (uid 1291):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
cmsblue2.fnal.gov:/uscmst1b_scratch/lpc1
                  8826G       0  14336G            944k       0       0
cmsblue1.fnal.gov:/uscms_data/d2
                     32       0  20480M           8749k       0       0
cmsblue1.fnal.gov:/uscms
                    864       0   2048M              41       0       0

The "-s" option tells the quota command to try to use units for showing the usage/limit output.
The errors in the output are normal. The two pertinent fields in this output are the first and third. The first shows how much disk is being used and the third shows what your limit is set to. As you can see in the example /uscmst1b_scratch/lpc1 shows a very high limit for this user. This is due to the fact that a default quota was set on this file system so we could use the quota facility to track individual users disk usage without actually limiting any one user or groups usage.
There is another useful option to the quota command which is the "-q". This option tells the quota command to only print information about file systems where you are over quota.

 What to do if you exceed your quota limit on BlueArc:

  1. Remove uneeded files
  2. Utilize the 3DayLifetime area in /uscmst1b_scratch/lpc1/3DayLifetime. As the name implies any data stored here is automatically removed after 3 days.
  3. Copy data to dcache.
  4. If you are a member of one of the LPC groups, you can utilize the storage areas allocated to that group. If you find you can not access the area allocated to the group you are a member of, send email to the coodinator listed on the above referenced web page to request access. These LPC group areas are located at:
    1. /uscms_data/d2/<group name>  (quota limit set; ksu to the physics group user before writing)
    2. /uscmst1b_scratch/lpc1/<group name>
  5. If all of the above are not sufficient, you can request more disk space.

 
 
 

Security, Privacy, Legal
Webmaster

Last modified: September 11, 2006