I know many folks out there are using Windows-based file servers or Windows-based Network Attached Storage (NAS) may be struggling with how to best manage that storage and considering how tight budgets are becoming, delaying when they have to increase or replace that storage is a high priority.
If you already have a large storage array, have plenty of capacity and are implementing thin provisioning; this will probably won't be applicable to you, but for those using smaller SAN-attached or direct-attached storage; you may find this interesting and possibly helpful.
I just finished reading a post in TechRepublic by Scott Lowe that discusses Microsoft's Single-Instance Storage (SIS) and how it can prevent your precious storage from being consumed by 20 copies of that 50MB vendor presentation or 10 copies of that 300MB training video that are scattered across your file server/NAS. I knew that SIS was integrated into Microsoft Exchange to reduce the number of duplicate messages, but never realized the same solution could be utilized at the file level. Scott Lowe's example of how SIS operates within Exchange provides a great overview of its function:
"...under Exchange’s SIS implementation, when a user sends a message out to 100 people with mailboxes in the same store, the message is stored only once. A pointer to this stored message is inserted into each user’s mailbox, thereby removing the need to store the entire message multiple times. This process can result in significantly lower storage requirements."
A key point to keep in mind is that SIS is only included with the Storage Server version of Windows Server 2003 R2 and Windows Server 2008, so it may require a migration if you're currently using Windows 2000 Server or Windows Server 2003 on your file server/NAS. Here's a quick breakdown on how the various SIS components work, again paraphrased from Scott Lowe's post:
- A process called the SIS Groveler searches through NTFS-based file systems looking for identical files
- Once duplicate files are located, they are moved to the SIS Common Store by a component called the SIS Storage Filter. There is a SIS Common Store for each SIS-managed volume.
- For each file that is moved into the SIS Common Store, a SIS Link is inserted into the file system (also by the SIS Storage Filter) in place of the original file. This SIS link is completely transparent to applications that may be accessing the file, which is actually located in the SIS Common Store. The SIS Storage Filter also handles client redirection to the version of the file stored in the SIS Common Store.
Microsoft also has a detailed whitepaper on SIS here and they have actually used this product themselves and reported the following benefits as of March 2006:
- Up to 40 percent reduction of storage needs on deployments so far at Microsoft
- 6.8 terabytes of storage space reclaimed so far in Microsoft deployment of SIS across more than 274 servers
- Reduced main memory cache loads through reduction of duplicate files
I'm looking forward to using SIS in my environment to reclaim some storage, reduce my backup windows and I might even be able to defragment some of my larger NTFS volumes now. Can anyone comment on their use of SIS? Is it as good as it sounds?
Comment Preview