Question on persistence file minimum size

**utu** · 11-09-2012, 05:54 PM

.
I recently did an update on my Synaptic.
I notice that my /var increased by 287 Mb.
Had I been using a 'minimum' persistence of 200 Mb,
wouldn't that have made knoppix-data.img unusable on the next boot?

**Werner P. Schulz** · 11-09-2012, 08:35 PM

Unusable not but no space left and the update will be corrupt.

It's a bad idea to use such a little persistent memory. I always use a pm as big as possible (max 4GB). Why buy a 256MB USB-stick, if you can buy a 16GB stick

**utu** · 11-09-2012, 08:55 PM

Greetings, Werner.

Shouldn't we petition KK to change the 200 Mb number built into the
Knoppix prompt to 400 Mb? One less pitfall for the new user?

**Werner P. Schulz** · 11-09-2012, 11:31 PM

No. Why fiddle around with such small devices? Today you only use for example 200 MB space on the device. But one day you need 2 GB additional space. New users should always use persistent memory as big as possible. USB sticks are cheap.

**utu** · 11-10-2012, 01:11 AM

.
I know what you mean and I agree, more is usually better.

What concerns me is that the prompt for establishing persistence seems
to say implicitly is that 200 Mb is probably a 'safe' minimum.
It isn't.
If one establishes a 200 Mb persistence file and his first act after
that is to update Synaptic, then what happens then is a crash
(certainly on the next boot) a new user might not know to anticipate.

I think the prompt and the minimum should be set higher for this reason.
More is better. That's not my point here. 200 Mb isn't enough.
Not enough for the minimum and not enough for the prompt.

**Werner P. Schulz** · 11-10-2012, 12:15 PM

If you do a Knoppix CD flash installation to a 1 GB USB stick, you can only establish a software device of 200 -269 MB (persistent memory). This is enough for personal settings, but with such a very, very small device you cannot do big jobs.

200 MB isn't a 'safe' minimum! Nobody claimed this.

You have to distinguish by yourself what you can do with such a Liliput device of 200 MB or with a big device of 4 GB.

**Werner P. Schulz** · 11-10-2012, 06:48 PM

I recently did an update on my Synaptic.
I notice that my /var increased by 287 Mb.
Had I been using a 'minimum' persistence of 200 Mb,
wouldn't that have made knoppix-data.img unusable on the next boot?

Unusable not but no space left and the update will be corrupt.

Now I tested it by myself. While trying to update you'll get a error message. Reboot fails because there is no space left for UNIONFS.

You have to restart with Knoppix cheatcode

Code: