108
votes
linux: How can I view all UUIDs for all available disks on my system?
The best command to use is
lsblk -f.
It will list all the devices and partitions, how they are mounted (if at all) and the tree structure of the devices in the case of using LVM, crypto_LUKS, or ...
- 1,081
45
votes
Accepted
Why is sync so important when making a bootable linux usb stick?
The dd does not bypass the kernel disk caches when it writes to a device, so some part of data may be not written yet to the USB stick upon dd completion. If you unplug your USB stick at that moment, ...
- 8,651
36
votes
Accepted
snap /dev/loop at 100% utilization -- no free space
No, having Snap images which consume 100% of their filesystem is perfectly acceptable. In fact, it's supposed to work that way.
A snap is a squashfs file carrying content and a bit of metadata that ...
- 7,278
27
votes
linux: How can I view all UUIDs for all available disks on my system?
To only get the UUID of a specific disk device (for example to be used in a script) you can use:
sudo blkid -s UUID -o value /dev/sdXY
where /dev/sdXY is the name of the device.
25
votes
Accepted
Best way to delete large amount of files by date
If the files are not modified after initial creation, you could delete if they have not been modified in over 90 days:
find /path/to/folder ! -type d -mtime +90 -delete
or
find /path/to/folder ! -...
- 9,065
19
votes
Check data integrity after copying thousands of files
Using MD5 sums is a good way, but the canonical way to use it is:
cd to the directory of the source files and issue:
md5sum * >/path/to/the/checksumfile.md5
If you have directories with many ...
- 9,068
19
votes
Accepted
Is my drive failing and is this the same reason my laptop is running slower?
Yes, your drive is failing:
5 Reallocated_Sector_Ct 0x0033 001 001 005 Pre-fail Always FAILING_NOW 9800
There’s nothing you can do to make the drive “better”. What you need to do next ...
- 450k
18
votes
How do I check TRIM?
Try lsblk -D
TRIM/discard is available, if the DISC-MAX column is not 0B
Example (SSD/trim available)
[root@foo bar]# lsblk -D
NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO
sda 0 4K ...
- 181
18
votes
linux: How can I view all UUIDs for all available disks on my system?
lsblk -o +uuid,name
You can see all the outputs that can be added to the -o (--output) with
lsblk --help
Also this will do the job
# blkid
- 2,435
15
votes
Persistent disk name /dev/sd'x', changing with almost every reboot
/dev/sdX has not been a stable identifier for a drive for a very long time (and indeed probably never was). Those are allocated in the order they're discovered, and different controllers are probed in ...
- 111k
14
votes
Accepted
Check data integrity after copying thousands of files
Unmount, eject, and remount the device. Then use
diff -r source destination
In case you used rsync to do the copy, rsync -n -c might be very convenient, and it is nearly as good as diff. It doesn'...
- 51.4k
12
votes
Accepted
Inaccessable partition with 477GB
nvme0n1 is not a partition, it is an entire disk: "NVMe controller #0, namespace #1". Unless you have some serious enterprise hardware, your NVMe disks have only a single namespace on them.
...
- 103k
11
votes
Accepted
Convert a single-drive LVM volume to a striped volume across 3 drives
I finally found a trick way.
The setup: Let's say our original drive is /dev/sda (PV is /dev/sda1) and our two new drives are /dev/sdb and /dev/sdc. All drives are 100 MB big.
The idea: Because all ...
- 20.4k
11
votes
Accepted
persistent device naming for NVMe storage devices
Short: No. You can not rely on the name of the descriptor. And you most likely never will.
The NVMe naming standard describes:
nvme0: first registered device's device controller
nvme0n1: first ...
- 156
10
votes
Accepted
What is the "~/.stack" directory?
From https://docs.haskellstack.org/en/stable/GUIDE/
The stack root directory holds packages belonging to snapshots and any stack-installed versions of GHC.
You can safely remove any or all of it, ...
- 236
9
votes
Accepted
tmpfs usage and resizing
Now, from what I read the tmpfs doesn't take physical storage, but uses the virtual memory of the machine. Is it correct?
Correct. tmpfs appears as a mounted file system, but it's stored in volatile ...
- 2,859
8
votes
Clear unused space with zeros (btrfs)
The correct and "smart" way to clear the free space is using:
fstrim /mountpoint
Use this on a mounted filesystem.
It's important to note that there is no security advantage to this. If you wish to ...
- 224
8
votes
Check data integrity after copying thousands of files
rsync -rc original-dir/ copied-dir/
-c causes rsync to compare files by MD5 checksum (without it, it normally uses only the timestamp and size for quicker comparisons).
This will also cause rsync to ...
- 4,835
8
votes
Replicating an SD card
If you're just looking to copy an SD card exactly from one to another then you can do so with dd on the command line.
You should NOT do this from your raspberry pi from it's own OS. This is because ...
- 19.4k
7
votes
Accepted
Is it true that rsync does not handle "File renames" gracefully?
There is no mechanism for rsync to track renames as it does not maintain state other than while it is running. If you rename /test/10GBfile to /test/10GBfile_newname on the source computer, then by ...
- 120k
6
votes
Accepted
why resize a PV instead of adding a new PV?
Summary: From a purely technical standpoint, it doesn't make much difference, but resizing is better. Once you add in practical aspects, adding a new partition is a clear winner.
From a strictly ...
- 111k
6
votes
Accepted
df command shows 100% full, even after deleting files it shows same usage (100%)
A reboot and re-mount would solve the problem I believe.
Reason: The reason behind this is that df utilize statfs(2) system call to get the File system stat. What it means that it checks open kernel ...
- 1,499
6
votes
How to make journald increase logs storage capacity?
It's necessary to setup SystemMaxUse=100G e.g.
- 245
6
votes
Accepted
Report how much space is used and available in storage in ZFS on FreeBSD
zfs list
Use the list option on the zfs command built into FreeBSD.
zfs list
Example:
$ zfs list
NAME USED AVAIL REFER MOUNTPOINT
zroot 4.41G 17.4G 88K none
...
- 1,577
5
votes
Accepted
In which file does Chromium store session storage data of the HTML5 webstorage
https://www.google.co.uk/search?q=leveldb%20log
https://www.quora.com/Why-does-a-LevelDB-database-use-a-directory-instead-of-a-single-file
New writes are first appended to a binary log file and ...
- 51.4k
5
votes
Why is there no lost+found directory in storage pool?
lost+found is a directory typically created when a mountpoint gets formatted with a standard Linux filesystem, like ext. I haven't played much with XFS, but afaik lost+found is specific to the fsck ...
- 1,164
5
votes
Accepted
Mirror Linux disk writes to secondary disk
You can use a MD RAID1 with the option --write-mostly.
subsequent devices listed in a --build, --create, or --add command will be flagged as 'write-mostly'. This is valid for RAID1 only and means ...
- 9,089
5
votes
Check data integrity after copying thousands of files
Along with the other fine answers above, I would like to also recommend considering hashdeep, from http://md5deep.sourceforge.net/. It has a good sized userbase in the scientific community, where they ...
- 150
5
votes
Is it true that rsync does not handle "File renames" gracefully?
--fuzzy has already been answered but there is another interesting hack involving hard links.
After the first transfer
$ rsync -avHP --delete-after ~/family/Photos remotebox:backups
You create a hard ...
- 6,084
5
votes
Accepted
why is the internal storage mmc and not sd?
/dev/sdX indeed once meant SCSI disk, but nowadays it covers anything with a SCSI-like interface, including SATA, USB storage and even old PATA when libata drivers are used. Some actually have ...
- 103k
Only top scored, non community-wiki answers of a minimum length are eligible