-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 read test: Telcontar:/data/storage_b/copias_usb_drives # hdparm -tT /dev/sde ; hdparm -tT /dev/sde ; hdparm -tT /dev/sde1 ; hdparm -tT /dev/sde1 /dev/sde: Timing cached reads: 27628 MB in 2.00 seconds = 13836.78 MB/sec Timing buffered disk reads: 358 MB in 3.01 seconds = 119.01 MB/sec /dev/sde: Timing cached reads: 27426 MB in 2.00 seconds = 13737.03 MB/sec Timing buffered disk reads: 390 MB in 3.00 seconds = 129.96 MB/sec /dev/sde1: Timing cached reads: 27798 MB in 2.00 seconds = 13921.69 MB/sec Timing buffered disk reads: 390 MB in 3.01 seconds = 129.52 MB/sec /dev/sde1: Timing cached reads: 27474 MB in 2.00 seconds = 13759.55 MB/sec Timing buffered disk reads: 388 MB in 3.00 seconds = 129.26 MB/sec Telcontar:/data/storage_b/copias_usb_drives/20230321 Seagate 2TB - Para_Pili # Read test with dd: Telcontar:/data/storage_b/copias_usb_drives # time dd if=/dev/zero of=dummy bs=1GiB count=1 oflag=direct 1+0 records in 1+0 records out 1073741824 bytes (1.1 GB, 1.0 GiB) copied, 6.54187 s, 164 MB/s real 0m6.545s user 0m0.005s sys 0m0.149s Telcontar:/data/storage_b/copias_usb_drives # Ok, that is normal. Write test: Telcontar:/data/storage_b/copias_usb_drives/mnt # time dd if=/dev/zero of=dummy bs=1GiB count=1 oflag=direct ; l -h dummy 1+0 records in 1+0 records out 1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.533335 s, 2.0 GB/s real 0m0.536s user 0m0.000s sys 0m0.152s - -rwxrwxrwx 1 root root 1.0G Mar 22 20:01 dummy* Telcontar:/data/storage_b/copias_usb_drives/mnt # time dd if=/dev/zero of=dummy bs=1GiB count=10 oflag=direct ; l -h dummy 10+0 records in 10+0 records out 10737418240 bytes (11 GB, 10 GiB) copied, 27.5384 s, 390 MB/s real 0m27.542s user 0m0.000s sys 0m1.501s - -rwxrwxrwx 1 root root 10G Mar 22 20:02 dummy* Telcontar:/data/storage_b/copias_usb_drives/mnt # time dd if=/dev/zero of=dummy bs=1GiB count=20 oflag=direct ; l -h dummy 20+0 records in 20+0 records out 21474836480 bytes (21 GB, 20 GiB) copied, 142.6 s, 151 MB/s real 2m22.604s user 0m0.000s sys 0m3.054s - -rwxrwxrwx 1 root root 20G Mar 22 20:04 dummy* Telcontar:/data/storage_b/copias_usb_drives//mnt # I don't understand how the write can be that fast. It is a cheap Seagate external 2.5 rotating rust thing. It can not have a huge internal ram cache, and the oflag=direct should disable the kernel buffer. mount: /dev/sde1 on /data/storage_b/copias_usb_drives/mnt type fuseblk (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096) Telcontar:~ # file -s /dev/sde1 /dev/sde1: DOS/MBR boot sector, code offset 0x52+2, OEM-ID "NTFS ", sectors/cluster 8, Media descriptor 0xf8, sectors/track 63, heads 255, hidden sectors 64, dos < 4.0 BootSector (0x80), FAT (1Y bit by descriptor); NTFS, sectors/track 63, sectors 3907024064, $MFT start cluster 786432, $MFTMirror start cluster 2, bytes/RecordSegment 2^(-1*246), clusters/index block 1, serial number 0a8b67aebb67aba00; containsMicrosoft Windows XP/VISTA bootloader BOOTMGR Telcontar:~ # - -- Cheers Carlos E. R. (from 15.4 x86_64 at Telcontar) -----BEGIN PGP SIGNATURE----- iHoEARECADoWIQQZEb51mJKK1KpcU/W1MxgcbY1H1QUCZBtTahwccm9iaW4ubGlz dGFzQHRlbGVmb25pY2EubmV0AAoJELUzGBxtjUfVjY4An03d/kCDX4klF97pvgV9 IBwCZBmzAJsHCeVWel4ux388OyAKjns2kPCZvw== =MUlt -----END PGP SIGNATURE-----