When installing Debian, or a derivative OS such as crunchbang, you may have opted to separate out your partitions/logical volumes to manage your disk space more finely.
I opted to do this. My partitions were set up thus:
$ sudo lvs
LV VG Attr LSize
home t420 -wi-ao-- 438.10g
root t420 -wi-ao-- 332.00m
swap_1 t420 -wi-ao-- 15.50g <-- way too big!
tmp t420 -wi-ao-- 369.00m <-- way too small!
usr t420 -wi-ao-- 8.38g
var t420 -wi-ao-- 2.79g
This was not working for me. Doing backups using the easy backintime was proving difficult, as backintime relied on more /tmp space than I had.
As I rarely touched swap space, I figured that 15.5G was probably a bit large for my needs. Thankfully, nabbing swap space and reusing it for the filesystem is easy as pie – and all achieved with no downtime.
Here’s the sequence I typed into a terminal. First, turn off swap:
$ sudo swapoff -a
Then resize the swap volume:
$ sudo lvresize -L 8GB /dev/t420/swap_1
Now re-format the swap partition before using it again:
$ sudo mkswap /dev/t420/swap_1
Then turn swap availability back on:
$ sudo swapon -a
And finally, resize the /tmp partition on-the-fly:
$ sudo lvextend -L +1G -r -v /dev/t420/tmp
Because the LVM tools have semi-awareness with respect to filesystems, the resizing of /tmp (using the -r switch) was achieved on-line – no need to log out, reboot or anything else. The verbose (-v) switch allowed me to see everything that was happening.
It all starts with that strange sound… In my machine’s case, a whining noise. As a sysadmin and/or experienced geek, you know something’s wrong. I suspect the head assembly has become detached and is scraping along the disk surface at 7200rpm…
Naturally, the usual recovery tools don’t work… and the drive sounds shot.
# pvmove /dev/sdd1 /dev/sdg1
/dev/sdd1: Moved: 0.0%
/dev/sdd1: Moved: 0.0%
/dev/sdd1: read failed after 0 of 2048 at 0: Input/output error
No physical volume label read from /dev/sdd1
Physical volume /dev/sdd1 not found
ABORTING: Can’t reread PV /dev/sdd1
ABORTING: Can’t reread VG for /dev/sdd1
# dd if=/dev/sdd1 of=dev/sdg1 bs=4096
dd: reading `/dev/sdd1′: Input/output error
2+0 records in
2+0 records out
8192 bytes (8.2 kB) copied, 0.0992418 s, 82.5 kB/s
# dd if=/dev/sdd of=dev/sdg bs=4096
dd: reading `/dev/sdd’: Input/output error
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 0.0205753 s, 199 kB/s
This is the third 1TB Seagate ES.2 drive I’ve had develop bad sectors. Although they have a 5 year warranty, they seem to start expiring after 3.
I have a Thinkpad T420 – now 2 years, 6 months old. Started to notice the fan seemed a bit noisier than normal and the CPU was reporting a temperature of around 60deg C, even when the machine wasn’t doing very much.
As suspected, 30 months of usage without a clean is a little bit too long. Cleaning a laptop fan can be fairly straightforward – this took just two screw removals. Of course, always seek advice and YouTube videos if you need help to do yours!
After the procedure, my laptop runs about 10-15deg C cooler and is much quieter.
Is there ever time in the day to reconsider your online security? I mean, really consider it?
Take the most common access point for communication in the 21st century – email. Yes, you read that right. It’s still email. Email is the root of online authentication for people worldwide, not only allowing them a “safe place” to recover lost account credentials, but also facilitating properly secured communications with the use of PGP signed and encrypted email. But is your email storage secure?
The woes of web mail
The “problem” with email is that its ubiquity spawned, some years ago, the explosion of “free” web mail services. All the big players provide it. These services are advertising-supported. In other words, the cost of providing such services are met by revenue generated from scanning your email and providing “relevant” adverts within your browser to click on. Each click is tracked and the advertiser billed accordingly.
An issue here, then, is that your email is scanned. All your emails are read by an indexing process which scours every single nugget of information. What information could that include? How could it be used? How about this little list for starters:
the date & time
the sender’s name and email address
their computer’s name
their network (i.e. their email provider, their ISP, any intervening mail routers)
their probable native language
their approximate location when sending the message (obtained from their original IP address)
your approximate location when reading the email (based on your IP address)
yours and their exact locations if using any location service
That’s not all
If the sender is using the same “free” web-mail service as you:
if they use a calendar in that service, what they were doing when they emailed you (giving an insight into the sender’s thought processes…)
if they maintain a contact list / address book in that web-mail service, that service may “know” you are a friend or family member of the sender
in this case, it will also know their friends – and your friends – and any shared friends too. It can start to build up a map of contacts – who knows who and possibly why.
Knowing “who knows who” means those related contacts’ web-mail services can be interrogated for commonalities, such as shared events (in a calendar), shared interests via a social network, and so on.
There are yet more ways your data can be exposed. If they are not using the same “free” web-mail service, but are using another service which they log into using their web mail service’s credentials:
that web-mail service provider could poll the other services to see what data you are sending (e.g. what you are posting) to those services
it can map any correspondence to or from your contact via its services even when not in relation to your email – e.g. It can expose a contact’s movements, their communications and interests in a given time-frame.
they can even be exposed by their use of related services from that provider. For example, new photos into a flickr or instagram account which is public, can be mapped back from their date, time and location to the IP address that was used to query location services.
Finally, a crucial problem with all online services is that there is no guarantee your data is actually deleted when you choose to delete it. After hitting “delete” through a web site, this could simply flag the email to be removed from your visible account and stored in MegaWebCorp’s vault of “deleted” email, remaining there forever. Or until needed…
This is the risk of putting data into another provider’s hands – what gets uploaded or stored in your name, stays there in your name, forever. What goes up, sometimes stays up.
Resolving the privacy crisis
Coming back to email, then, the first priority for someone who wants to maintain some privacy with respect to their life activity needs first to remove the source of indexing from MegaWebCorp’s database – the link between all things you do, your email address.
When the email address is removed from the purview of MegaWebCorp’s systems, your online activity can start to become your business – not the advertiser’s.
Getting your own address is simple. You can register a domain name with any of numerous providers around the world and sign up for a low-cost hosting plan. For any person who values their privacy and the sanctity of anonymity, this is a small hurdle to overcome.
For the gain in privacy you can achieve by hosting your own web site, the price attached to a “free” web-mail account may seem rather high.