The sale of external disk storage systems kept up its momentum by posting a double-digit growth for the fifth consecutive quarter, a report said.

The total disk storage capacity has reached 4965 petabytes in the quarter which represented a more than 45 per cent year-over-year increase since 2010.

The total revenue posted a growth of about 13.2 percent, totaling just under $5.6 billion in the first quarter of 2011.

The worldwide disk storage market is off to a strong start in 2011, said Amita Potnis, senior research analyst, Storage Systems at IDC (International Data Corporation). Although the market declined sequentially in the first quarter, due to a seasonal budget flush in Q4, year-over-year growth can be seen as end-users are taking advantage of easing budget constraints while adopting new capabilities available in the market he added.

Information infrastructure giant EMC Corporation continued to lead the external disk storage systems market with 27.3% revenue share in the first quarter. The company was followed by NetApp with 13.5 percent and IBM in third with 12.2 percent market share. HP ended the quarter in fourth with 10.5 percent, the IDC website reported.