@eljamm.
Good hint. I have checked partitions on my PC under win11 and Gentoo linux,
/dev/sda7 is NTFS formated partition. But Gentoo see /dev/sda disc as /dev/sdb.
And Nixos boot and mounts 7th partition sometimes as /dev/sda and sometimes as /dev/sdb. Why?
Gentoo’s fdisk -l looks like that
Disk /dev/nvme0n1: 465.76 GiB, 500107862016 bytes, 976773168 sectors
Disk model: CT500P5PSSD8
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: gpt
Disk identifier: 4FADB7C3-1AE4-4D56-BAF5-4527C8AD862F
Device Start End Sectors Size Type
/dev/nvme0n1p1 2048 485375 483328 236M EFI System
/dev/nvme0n1p2 485376 518143 32768 16M Microsoft reserved
/dev/nvme0n1p3 518144 311668735 311150592 148.4G Microsoft basic data
/dev/nvme0n1p4 311668736 312983551 1314816 642M Windows recovery environment
/dev/nvme0n1p5 312985600 508297215 195311616 93.1G Linux filesystem
/dev/nvme0n1p6 508297216 703608831 195311616 93.1G Linux filesystem
/dev/nvme0n1p7 703608832 976771071 273162240 130.3G Linux filesystem
Disk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: SanDisk SDSSDH31
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: 0x66c58bda
Device Boot Start End Sectors Size Id Type
/dev/sda1 2048 209717247 209715200 100G 83 Linux
/dev/sda2 209717248 419432091 209714844 100G 83 Linux
/dev/sda3 * 419432448 629147647 209715200 100G 83 Linux
/dev/sda4 629147648 1953525167 1324377520 631.5G 5 Extended
/dev/sda5 629149696 838864895 209715200 100G 83 Linux
/dev/sda6 838866944 1048582143 209715200 100G 83 Linux
/dev/sda7 1048584192 1258299391 209715200 100G 83 Linux
/dev/sda8 1258301440 1533028351 274726912 131G 83 Linux
/dev/sda9 1533030400 1953525167 420494768 200.5G 83 Linux
Disk /dev/sdb: 1.82 TiB, 2000398934016 bytes, 3907029168 sectors
Disk model: ST2000LM015-2E81
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0xd714433e
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 419432447 419430400 200G 7 HPFS/NTFS/exFAT
/dev/sdb2 419432448 838862847 419430400 200G 83 Linux
/dev/sdb3 838862848 1107298303 268435456 128G 82 Linux swap / Solaris
/dev/sdb4 1107300350 3907029167 2799728818 1.3T 5 Extended
/dev/sdb5 1107300352 1526730751 419430400 200G 83 Linux
/dev/sdb6 1526732800 1946163199 419430400 200G 7 HPFS/NTFS/exFAT
/dev/sdb7 1946165248 2365595647 419430400 200G 7 HPFS/NTFS/exFAT
/dev/sdb8 2365597696 3907029167 1541431472 735G 7 HPFS/NTFS/exFAT
Partition 4 does not start on physical sector boundary.
Nixos is installed on /dev/nvme0n1p6 and Gentoo on /dev/nvme0n1p7