Overview

The new data path in DXi 2.0 software runs faster than before on the same hardware. It allows data transfer inline from the presentation layers through memory cache. In other words, data only touches the disk once during ingest, and only unique bits are written to disk. The cache/buffer area, which stored raw data in DXi software 1.x, has been eliminated. The corresponding need to truncate this cache/buffer area has also been eliminated. This means that truncation is not part of the space management process.

DXi 1.x Software Data Path

 

 

• QBFS File system over SNFS.
• QBFS provides “file system” for user data.
• QBFS splits data into 256 MB chunks.
• SNFS holds meta data, tags for de-duplicated data and un-deduplicated data.
• Dedupd moves data between blockpool (deduplicated) and SNFS (un-deduplicated).

CIFS

• Client writes via CIFS to /Q file system.  Postprocessing dedup.
• Client reads via CIFS from /Q file system.  “Semi-inline” un-dedup
• Standard CIFS server (except for behind the scene dedup)

DXi 2.x Software Data Path

 

 

 

 NFS

• QFS provides “file system” to user data.
• qfsd moves data between QFS and blockpool wrapper.
• qfsd uses shared pcache memory for data.

CIFS

Samba has been updated to a newer version than what was in 1.x (3.5.2 vs 3.2.7). Therefore, this upgrade resolves a number off issues that have been previously encountered.
There is improved CIFS support:

• Support Windows 2008 R2 domain
• LDAP signing (enabled via GUI or CLI)
• NextGen architecture.
• Shares are now located in /snfs/ddup/shares.
• Client writes via CIFS to ddupfs. Inline dedup.
• Client reads via CIFS from ddupfs. Inline un-dedup.
• CIFS client and server still expect file system behavior.
• 2.0 Non-dedup share != 1.x Non-dedup share.
• ddupfs is new with DXi 2.x. It does the following:
  • Provides “posix-like” file/directory personality and interface to dedup
  • Shields the application from idiosyncrasies and special requirements of dedup
  • Serves as a single point of maintenance
  • Allows the file service application to easily be ported to take advantage of dedup (things like the ftp server and scp server)

Location of Configuration Files

The configuration files are located in the same place for DXi 1.x software and DXi 2.x software:

•  /etc/samba/smb.conf
•  /snfs/common/galaxy-config/nas/smb.conf.extra
•  /snfs/common/galaxy-config/nas/node1/smb.shares
• Kerberos config file in /etc/krb5.conf (no change) 

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Ways to Start / Stop Services

Services can be controlled using the appropriate startup script in /etc/init.d or by using the service utility. The service utility points to the scripts in /etc/init.d

• Same on DXi1.x and 2.x software: Usage: service < option > | --status-all | [ service_name [ command | --full-restart ] ]
  • For example: service qfsd stop or /etc/init.d/qfsd stop
• Galaxy 2.0: depends on the bpw service being started and running.

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What's Next?

OST Architecture >