Scratch Space

isginf operates a storage server for large data that primarily does not need backup. An extension of the service allows for disk-to-disk backup at twice the cost.

Free

Research groups can request 2 TB of scratch storage for free with the option to increase to 5 TB if needed.

Shared Disks

Research groups with needs in the range 15 TB and above can buy disk space in the shared pool.

Dedicated Disks

Research groups with special requirements on IOPS can buy disks for a dedicated pool. Disks are added to the system in groups of nine at once.

Disk to Disk Backup

Research group can buy twice the amount of space for shared or dedicated disks. The second half will be allocated in a geo-redundant backup server. Selected data in the scratch server will be replicated daily via snapshots to the space in the backup server.

Availability

The system needs to be booted from time to time to upgrade the operating system. This results in short outages. This is typically announced to the ITCs beforehand.

Data Safety

We use server-grade hardware that rarely fails and there are cold spare components already on-site to restore service in case of a hardware failure. The storage uses RAID 6 on groups of nine disks to make it resilient even to multiple hard drive failures. Snapshots of the file systems protect against accidental deletion.

Speed

The spinning disks allow only a limited amount of IOPS. For acceleration all metadata of files is written to dedicated SSD drives. Directory listings are fast but reading many files may be slow.

Backup

Access

Access to the shares can be through NFS4 with Kerberos or SMB/CIFS. NFS3 access is possible but requires separate shares and directories.

Each group that uses this service usually has a share scratch that is available to all users of the group.

The available shares for each group are typically worked out with the groups ITC.

SMB/CIFS

The scratch server is accessible via SMB at:

OS	Path
Windows	\\scratch.inf.ethz.ch\scratch or \\scratch.inf.ethz.ch\scratch-secure
macOS	smb://scratch.inf.ethz.ch/scratch or smb://scratch.inf.ethz.ch/scratch-secure
Linux	//scratch.inf.ethz.ch/scratch or //scratch.inf.ethz.ch/scratch-secure

The scratch-secure share is encrypted and requires SMB3 protocol.

NFS

The NFS exports are per group:

Groups are listed here. For mounting in /etc/fstab use the following mount options:

Integration in isginf Linux Installations

On Linux installations managed by isginf the shares are accessible under /pub (via autofs), i.e., the scratch share is available under /pub/scratch.