How to format a disk such that it's System is HPFS/NTFS/exFAT rather than GPT
Linux - SoftwareThis forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
All things being equal I do not believe that GPT is slower then a MSDOS partitioned drive. Do you have another drive of the same model number? Easy enough to partition the slow one to MBR.
True , if both drives are of identical make/models and partitioned the same for start then what could be the difference.
You can use "hdparm -I /dev/sdc" to see what the drive actually reports. Note the upper case "I". That command might not work over a USB interface, but should always work over SATA/eSATA.
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Disk /dev/sdc: 1953525168 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 32792A9E-FD22-4C4C-9160-4D0028DCBA06
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 2048-sector boundaries
Total free space is 3437 sectors (1.7 MiB)
Number Start (sector) End (sector) Size Code Name
1 2048 1953523711 931.5 GiB 0700 primary
For the good/fast drive:
Partition table scan:
MBR: MBR only
BSD: not present
APM: not present
GPT: not present
***************************************************************
Found invalid GPT and valid MBR; converting MBR to GPT format.
***************************************************************
Disk /dev/sdc: 1953525168 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 7D5E7EF5-6576-40D6-A20D-13EFB5CD8708
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 2048-sector boundaries
Total free space is 5485 sectors (2.7 MiB)
Number Start (sector) End (sector) Size Code Name
1 2048 1953521663 931.5 GiB 0700 Microsoft basic data
You can use "hdparm -I /dev/sdc" to see what the drive actually reports. Note the upper case "I". That command might not work over a USB interface, but should always work over SATA/eSATA.
That didn't work on either drive (using eSATA). Results:
/dev/sdc:
HDIO_DRIVE_CMD(identify) failed: Bad address
The recovery and transformation menu in gdisk can convert a GPT back to MBR. Out of curiosity are most of the disks using MBR that you test?
ext4 has been the common format; we're adding NTFS as a supported format but when the system formats a disk with NTFS, the benchmark is too low to be useful. I was trying to determine the limits and couldn't understand how one could work so well. I don't know how I created the "good" one but the more I learn about how it's formatted, the worse it sounds. Especially regarding GPT. We just qualified a 4TB SSD, and single files can be that large, so GPT is a requirement.
Pursuing this is probably not worth the effort. GPT may not be the performance issue but I don't know how the benchmark works. The benchmark routine belongs to Engineering and it's not worth it to them to figure it out until a customer wants it.
I've learned a few things. Thanks (to everyone) for helping,
This 512 sector size is certainly bogus, the real sector size is 4096. Thus, the partition is misaligned.
I don't know why you assume that, fdisk on a 2tb seagate on fedora 23 shows 512/512.
Quote:
Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000da519
Also, misalignment isn't that significant on newer drives, in reality we never see the real physical sector alignments, the drive firmware maps things physically unseen by the os.
I don't know why you assume that, fdisk on a 2tb seagate on fedora 23 shows 512/512.
When was it manufactured? Some drives lie. I have more than one such, and most I own made since 2010 are Seagate.
Quote:
Also, misalignment isn't that significant on newer drives, in reality we never see the real physical sector alignments, the drive firmware maps things physically unseen by the os.
Got any proof? That's directly opposite my understanding, at least WRT writing. Check this Seagate explanation.
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.