How To Replace Seagate Disk Drives
Seagate is the world's largest enterprise class disk drive manufacturer. Not only does Seagate sell disk drives directly to end users, but they manufacturer the majority of drives that HP, IBM, SUN / Oracle, and EMC re-badge and re-sell. As such, just ordering a Seagate model number may not get you the optimal replacement or upgrade drive.
- OEM Firmware and Drive Capacity
- Identifying Retail Seagate Disk Drives
- Firmware Mode Page Considerations
- Remember: Avoid New Bulk and New Pulls. Drives should be packed in Clamshells.
Seagate manufactures disk drives for system builders of all sizes, from the mom-and-pop computer shop down the street to HP. It is true that re branded drives sold by HP, IBM,and DELL are physically the same as generic / retail units. However, the firmware on the drives changes the behavior of the drives significantly. The most critical issue involved with replacing a failed Seagate disk drive is getting the capacity correct. With Seagate disk drives, generic firmware usually unlocks the largest usable capacity on a drive. OEM firmware from HP, IBM, and SUN usually locks the capacity of Seagate drives down. When replacing a drive in a RAID, the replacement drive must match the capacity exactly. In some cases you can replace a lower capacity drive with a higher capacity drive, but never the other way around.
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| Generic (retail) Seagate Cheetah disk drives usually have firmware labels with revision levels starting with "000." For example, the latest firmware on the Cheetah 10K.6 is 0008 and the latest firmware on the Cheetah 10K.7 is 0005. On Seagate Barracuda and Constellation SATA drives, it is more difficult. Barracuda ES.2 drives will have "SN0X" firmware. Some OEMs put their own logo on Seagate's drives to help customers identify certified drives for their environment. However, this is not always the case. On older SCSI models, a DELL disk drive will look almost identical to a generic disk drive. Vendors often try to resell DELL drives as generic, often because they not know the difference between a generic or DELL certified drive themselves. If in doubt about what kind of Seagate replacement drive you need, please contact us! A little pre-sales support will save you (and us!) a large amount of frustration down the road. Remember: Even though a DELL OEM ST336607LC disk drive has only (2) less 512 byte blocks available than the generic version (71687370 vs. 71687372), a RAID with generic disks WILL NOT accept a DELL certified drive! |
| While trying to replace a disk drive in a RAID with an OEM drive that has too small of a capacity is a sure way to ruin your day, there are other (less obvious) problems involved with using the wrong firmware on a drive in your system. Disk drive operation can be controlled by mode pages. HP, IBM, SUN, DELL, and EMC customize Seagate disk drives for optimal operation with their RAID controllers and HBAs. Mode page settings can have adverse performance and data integrity effects. For example, Compaq RAID controllers traditionally only accepted disk drives with automatic SMART reporting enabled (MRIE Bit 4.) SMART reporting MRIE 4 constantly has disk drives check SMART statistics and report 01x5D sense keys to the controller whenever a SMART parameter is out of spec. On the other hand, DELL PERC controllers traditionally use a polling mechanism to request SMART status from a drive (MRIE Bit 6) rather than waiting for the drive to self report. This increases performance. Installing a DELL OEM drive into a Compaq environment, without changing the mode pages, will prevent Compaq's RAID status monitoring from ever seeing SMART trips since the drive is configured to only send SMART updates when requested whereas the Compaq RAID controller expects to receive notifications from the drive. There are hundreds of mode pages on SCSI, SAS, and FC disk drives. Many of them can adversely affect performance. For example, we have found that enabling the PERF (Performance) mode page along with WCE (Write Cache Enable) and RCE (Read Cache Enable) can speed the number of I/Os on a 10K disk drive from 50 IOPS to 97 IOPS. Here is an interesting discussion we are following about OEM disk drives.The user was lucky that his drives only had an LED mode page setting problem rater than a more serious read/write behavior problem. |
| New Bulk and New Pull disk drives are not actually new! (We consider new disk drives to have close to 0 power on hours and be sealed in retail packaging!) Bulk and Pull disk drives are either used or factory rejected units. Since they have been used or rejected, you don't know how the drive mode page settings have been set or what type of firmware you are getting. Often vendors advertising "new bulk" products outside of distribution cannot supply matching disk drives (matching firmware revisions, matching OEM part numbers, etc.) if you buy more than 1 disk drive from them. TIP: Seagate disk drives almost always ship in plastic "Seashell" (Clamshell) plastic carriers. Merchants advertising "new" drives in anti-static bags probably are not offering truly new drives. (This is not to say that quality refurbished Seagate drives cannot be sealed in anti-static bags.) Learn more about how to choose a spare parts vendor. |
