Archive:Advantages of using Novell SMS (Storage Management Services) architecture to backup Novell / OES data

From SEPsesam
Jump to: navigation, search
Icon archived docs.png THE CONTENT OF THIS PAGE IS OUTDATED
SEP AG has discontinued support for obsolete SEP sesam versions. Instructions are still available for these SEP sesam products, however, SEP AG accepts no responsibility or liability for any errors or inaccuracies in the instructions or for the incorrect operation of obsolete SEP sesam software. It is strongly recommended that you update your SEP sesam software to the latest version. For the latest version of SEP sesam documentation, see documentation home.

More information about Backup in Novell environments - see the article: Backup principles using SEP sesam in a Novell OES environment

The Storage Management Services (SMS) architecture by Novell is a collection of services providing backup, restore, and data migration. When considering backup solutions for OES resources, it is important to consider the pros/cons of backup solutions and whether they can utilize the Novell SMS (Storage Mgmt Services). architecture.

OES-NetWare

If the server to be backed up is an OES-NetWare server, then to backup the File System (FS), the backup software must talk to the FS Target Service Agent (TSAFS) unless it uses its own proprietary interface to the FS. Given that NetWare is end-of-life, fewer and fewer backup products are supporting the NetWare platform and customers normally need to update their backup software when migrating NetWare resources to OES-Linux. It is a good opportunity for customers to completely re-think their backup infrastructure since it is often the case that the NetWare backup products are obsolete.

OES-Linux

On OES-Linux, there are two choices when it comes to FS backup: without TSA (i.e. native Linux access to File System), or with TSA.

Advantages of FS backup without TSA:

  • Performance may be better than with TSA. Direct backup avoids the SMS layer. However, this can be mitigated if TSA-enabled backup software is capable of backing up multiple streams concurrently in order to provide enough sustained throughput to the tape drive to avoid "shoeshining". Note that NSS metadata can be backed up without TSA, as long as the appropriate NSS switches are present to expose the metadata as Extended Attributes. Since many mainstream backup products no longer support SMS or have only limited support for it, this is an acceptable workaround, but still a workaround...see the Disadvantages as follows.

Disadvantages of FS backup without TSA:

  • If the FS volume leverages the NSS Compression feature, then all compressed files will become uncompressed when touched by the backup software.
  • The backup software is unaware of OES Virtual Server Cluster Pool resources managed by Novell Cluster Services (NCS); it can only backup on a node-specific basis. If a cluster pool is migrated from Node1 to Node2, then the backup software will consider Node2 as a completely different server and perform another full backup. This would waste time and resources. With TSA, and as long as the backup product can work with Cluster Pool resources, if the resource is failed over, the backup job can continue from where it left off; and it will not do a full backup when only an incremental is required. Furthermore, some backup software which claims to be TSAFS-aware might still not work with cluster resources.
  • Backups created on OES-Linux without TSA, cannot be restored to a NetWare server
  • Backups created on a NetWare (with TSA) cannot be restored to OES-Linux server without TSA. For migration scenarios or with a mixture of OES-NetWare/OES-Linux servers this can be important.
  • TSA-unaware backup software cannot work with TSA's to perform backups of online database resources such as eDirectory, GroupWise, and iFolder data. In order to achieve reliable backups of this data, the administrator must dump the database on a regular basis, and backup the dumped data and exclude the live data.

TSA-aware backup products provide the customer with much more flexibility and are also backwards-compatible with TSAFS on legacy NetWare servers. The cluster compatibility can also become a critical issue; customers might purchase a mainstream backup product and realize only too late that it will not work well with their cluster pool resources.