> From: namitaiyer <[EMAIL PROTECTED]> > Subject: [twincling] Re: filesystem migration > Sent: 12 Mar '07 09:39 > > > Hi all: > > > > I was reading a document on file system basics, when I came across > the term 'File System migration'. > > > > It is described as - "technique to move a filesystem from one server > to another." > > > > Can somebody explain what is the mechanism an how it works ? > > > > Thanks in advance. > > > > thanks > > Saifi. > > > > Hi Saifi, > > The term FileSystem Migration usually refers to migration from one > FileSystem to another. > > The technique of moving a file system from one server to another is > usually referred to as "Data Migration". > > Typically data migration is required when two companies merge or data > centers move from one vendor's storage to another. It could also be > driven by new DR (Disaster Recovery) site requirements or ILM > (Information Lifecycle Management) needs. > > Data migration due to the above reasons would involve movement of > terabytes of data and migration windwows are not more than a weekend > long. Hence, software solutions dont work well. > > However, the catch here is that data migration is a less frequent > activity (usually a one time activity). So no customer will buy > hardware specially for data migration. > > So vendors provide this feature as an add-on to already existing > products. > > As far as the mechanism is concerned, that depends on where the > feature is provided (as a part of which product). > > At the host end you can have it in software like the volume manager > (Eg. Veritas VM) - just mirror the lun. On the storage end you can > have the array or NAS appliance provide this feature (Eg. EMC SAN Copy). > In this case you cannot migratie to another vendor's array, of course :-) > > On the network, you can have appliances (Eg. FalconStor's IPStor, > which is a SAN Management appliance provides this feature as an > add-on) or switches (eg. DMM (data migratio manager) - an addon to > Brocade's Silkworm 68000). > > Typical performance expectation for data migration is 1TB an hour or > more. This is only achievable thru block copy, which means reads would > bypass the filesystem. Hence the term 'Filesystem migration' cannot be > used in this case. > > Hope this helps, > > Namita >
Hi Namita: Thanks for the detailed explanation. What I understand from your mail, is that there are multiple approaches to accomplish filesystem migration. While we are on this topic, I am curious to know what would be 'fs migration' or 'data migration' in the context of say clustered environment or a SSI (single system image) environment. Thanks for your time in advance. thanks Saifi.
