1 |
On Wednesday, 25 November 2020 17:37:15 GMT Dr Rainer Woitok wrote: |
2 |
> Greetings, |
3 |
> |
4 |
> since my old 64 GB Verbatim USB sticks became too small, I bought two |
5 |
> new 128 GB Philips sticks. Because I need to read and write them on |
6 |
> both, a stand-alone Windows laptop (not connected to the internet) runn- |
7 |
> ing Windows Vista and Cygwin and my Gentoo laptop, I encrypted them with |
8 |
> old TrueCrypt on the Windows box, using them under Gentoo in TrueCrypt |
9 |
> compatibility mode. |
10 |
> |
11 |
> This worked well with the Verbatim USB sticks (which probably are USB |
12 |
> 2.0), but while reading the new USB 3.0 Philips USB sticks is signific- |
13 |
> antly faster than reading the old Verbatim USB sticks, writing to them |
14 |
> is slow as hell under Gentoo. And writing to the Philips USB sticks on |
15 |
> the old Vista laptop with USB 2.0 ports clearly outperforms writing to |
16 |
> them using the Gentoo laptop's USB 3.0 ports. |
17 |
> |
18 |
> This could be a problem with TrueCrypt/VeraCrypt or with somehow miscon- |
19 |
> figured USB ports. To check for the latter I provide below all kernel |
20 |
> configuration variables I regard USB related in the hope that some know- |
21 |
> ledgable people might find a glitch in there: |
22 |
|
23 |
Check dmesg to see if initialisation of the USB 3.0 drive throws up any |
24 |
errors. Then check 'lsusb -t' to make sure it has been recognised as a USB |
25 |
3.0. |
26 |
|
27 |
If write operations without TrueCrypt/VeraCrypt are equally slow, then |
28 |
obviously the problem is not with encryption. |
29 |
|
30 |
I've read in a number of articles the erase block size on most USB flash |
31 |
(NAND) is 128KB, which incurs a lot of operations on a write, when using Linux |
32 |
with its 4K size sectors. Partitioning the USB drive to use 128KB sectors and |
33 |
then aligning the fs on it should improve matters. |
34 |
|
35 |
I found this article which mentions an experiment with ext4 fs. A more |
36 |
effective search should hopefully bring up examples on FAT fs. |
37 |
|
38 |
HTH. |