IBM System x3500 M4 16Internal backup unitsThe server supports the internal tape drive options listed in the following table.Table 9. Internal tape drivesPartnumberDescription Maximum quantitysupported46C5364 IBM RDX Removable Hard Disk System - Internal USB 160 GB Bundle 146C5387 IBM RDX Removable Hard Disk System - Internal USB 320 GB Bundle 146C5388 IBM RDX Removable Hard Disk System - Internal USB 500 GB Bundle 146C5399 IBM DDS Generation 5 USB Tape Drive 139M5636 IBM DDS Generation 6 USB Tape Drive 143W8478 IBM Half High LTO Gen 3 SAS Tape Drive 2*44E8895 IBM Half High LTO Gen 4 SAS Tape Drive 2*49Y9898 IBM Half High LTO Gen 5 Internal SAS Tape Drive 2** Note: With standard models, installation of a second tape drive requires removal of DVD-ROM.USB tape drives are attached to the internal USB connector. SAS tape drives require SAS HBA (soldseparately). See Table 13 for list of available SAS HBAs.For more information, see the following at-a-glance guides:IBM RDX Removable Disk Backup Solution at-a-glance guidezhttp://www.redbooks.ibm.com/abstracts/tips0726.html?OpenIBM DDS Generation 5 USB Tape Drive at-a-glance guidezhttp://www.redbooks.ibm.com/abstracts/tips0755.html?OpenIBM DDS Generation 6 USB Tape Drive at-a-glance guidezhttp://www.redbooks.ibm.com/abstracts/tips0725.html?OpenOptical drivesThe server supports the optical drive options listed in the following table.Table 10. Optical drivesPart number Description MaximumquantitysupportedStandard modelswhere usedNone* Half-High SATA DVD-ROM 2 A2x, B2x, C2x, C4x, D2x, F2x,G2x, H2x, J2x81Y6404 Half-High SATA Multiburner 2 -* This option is only available via CTO or is already installed in standard models.The two half-high drives in the table can be installed in any open 5.25" drive bay (Figure 5).