I know that this may be a stupid question to some but I don't often work with SCSI drives with what seems to be non-standardized sizes compared to SATA drives. I currently have a RAID1 of two drives on an old Dell server and one of the drives has failed.

The current drives are Maxtor 73GB SCSI Ultra320 80-pin 10k (8J073J002075E). When searching for replacement drives of similar specs, it seems that 72.8GB drives are most commonly listed and 73GB drives are more rare.

Is this a case of a manufacturer rounding up on the capacity or is there a real 200MB difference going to cause an issue?

(Note: I realize that the general rule of thumb is to replace with all the same specifications or higher -- this question is whether the difference between 72.8 versus 73 is just labeling versus actual technical difference in size.)

  • 3
    I am included to advice you to just plug in a 128gb SSD an be done with it. Performance will NOT go down.
    – TomTom
    Feb 15, 2017 at 16:03
  • 1
    You must be working on unsupported kit here - U320 is OLLLLLLD dude, I have USB memory sticks that will be quicker than this could ever go.
    – Chopper3
    Feb 15, 2017 at 16:22
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    @Chopper3 The kit is ancient and should have been put out to pasture years ago, but the general question about drive sizes in recovering a degraded RAID array is sound and still relevant today. Feb 15, 2017 at 16:38
  • You're correct that it is old -- about 10 years. Using off-lease hardware for 5 years will do that, but not every company/customer is willing to upgrade their infrastructure every few years or can/chooses to purchase new hardware. The question is specific because this "fix" is only intended to be used for a couple months while newer hardware is obtained/configured/rolled out. 72.8GB drives are far cheaper and more available than 73GB, which is more attractive when it is all going to be trashed soon.
    – Jacob S
    Feb 15, 2017 at 18:42
  • I will disagree with the fellows above that the server should be put away. While it is not complaining about its workload it's good enough to stay in the workforce. I have an HP Gen.2 which runs on those Maxtor SCSI drives. I recently purchased a lot of 10x73GB model. 5 to go in the server and 5 for spare parts. If I recall correctly I got them for $14 each on ebay. I am sure you should be able to trace some down for a price which it will not matter if it is the 72.8 or the 73 GB model. Feb 15, 2017 at 22:12

1 Answer 1


What the marketing people slap on the front of a drive doesn't matter. What matters is how many logical blocks the drive actually has usable.

# fdisk -l /dev/sda
Disk /dev/sda: 223.6 GiB, 240057409536 bytes, 468862128 sectors

In this drive I have 468862128 logical blocks, so if I need to replace the drive, the replacement must have the same number, or more.

With a smaller number of blocks, it will simply be impossible to recover the array to the disk, because there won't be enough space. With a larger number of blocks, the remaining space will go unused, but it will be possible to rebuild the array onto the drive.

  • You are certainly correct, and if I had those specs for hardware I don't have, I wouldn't ask the question. I'm looking more for experience here from people who know whether a Maxtor 73GB and an <insert> 72.8GB are realistically the same. e- But thank you for taking the time to answer.
    – Jacob S
    Feb 15, 2017 at 18:44
  • @JacobS The only way you're going to find out is to go and check them yourself. Now you have the ability to do so. Don't count on anybody here (or anywhere else) having one laying around. Most of us scrapped them years ago, though you might get lucky... Of course, you could just get specifications from whoever is supplying the drives. Feb 15, 2017 at 18:45
  • Wasn't hoping to, just wondered if anyone had experience or dealt with this in the past and knew whether it was an issue. Buying hardware to see if I need to buy different hardware isn't a solution. Asking a question of people who might know an answer is free. If all else fails, I'll purchase the 73GB labeled drive. While this answers how* I can find out if I had two like drives I wanted to compare, this information unfortunately doesn't help me in my situation or answer the original question. I'm doubtful newegg has sector data on refurbished drives. But again, thank you for taking the time.
    – Jacob S
    Feb 15, 2017 at 19:08

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