FAQ about group disk (as of 1 May, 2018)

About group disk

The group disk is a shared storage that can use the capacity set by the TSUBAME portal for each TSUBAME group written in TSUBAME3.0 User's Guide "3.2 High-speed storage area" 

  • Usage period: From purchase date to the end of the fiscal year (end of March).

 For example, if you purchase 10TB on 1 May, 3,960,000 points are reuired (36,000 points x 10TB x 11months(until the end of March).
    Even if you buy 10TB on 31 May, which is the end of the month, it will be 3,960,000 points as you would purchase on 1st day.

  • Purchase unit: 1TB unit(2,000,000 inode)
    Up to 300TB per group.

 If unused, you can receive return points by reducing purchase capacity.
 For example, if you purchase 1TB in April, and delete all data in May to reduce capacity, 396,000 points (36,000 points x 1TB x 11months (until the end of March) will be returned. 

    Reference:TSUBAME Portal User's Guide "10. Management of Group Disk"

What is the group disk grace period ?

Group disks are reset once at the end of the fiscal year, and all group disks are in a grace state that can only be read/deleted.
This period is called the grace period, and usually it will be maintained around the middle of April (17 Apr. on this year).

Reference:TSUBAME Portal User's Guide "10.2. About the validity period of the group disk" 

If the data of the previous year remains and you purchase it after the grace period, it becomes as follows.
For example, if you purchased 50TB in the previous year and you used a capacity of 45TB.

1) When 45TB is deleted during the grace period and the used capacity is 0.
     You can purchase from 1TB which is the minimum capacity.

2) When 25TB is deleted during the grace period and the used capacity is 20TB.
    Available from over 20TB.

2) If the used capacity is not deleted during the grace period (used capacity is 45TB)
    Available from over 45TB.

*If you do not need the previous year's data, please delete it during the grace period.

Related FAQ

Checking the usage of group disks with command
Can not establish CIFS connection to the group disk
"Disk quota exceeded" error is output