8 votes
Accepted

How does EXT4 handle sudden lack of space in the underlying storage?

When the block device overcommits its available data capacity like when using thin provisionning or has other reasons to not be able to accept more writes, like having a snapshot full, it has to send ...
A.B's user avatar
  • 35.3k
6 votes
Accepted

What is the significance of GPT's "Partition Type GUIDs"?

The idea behind all these different partition type GUIDs is that they can be used to mount a system’s volumes without /etc/fstab. The partition types are defined in the discoverable partitions ...
Stephen Kitt's user avatar
5 votes

How does EXT4 handle sudden lack of space in the underlying storage?

It depends on the filesystem (and possibly mount options) and the underlying storage. In most cases, a failure to write to a block device due to it being over-committed on space will immediately be ...
Austin Hemmelgarn's user avatar
4 votes
Accepted

What can cause “multiply claimed blocks” on an ext4 drive?

As stated very early by Theodore Tso himself, there can be two immediate reasons for “Multiply claimed blocks” to be reported by fsck : One is that one or more blocks in the inode table get written ...
MC68020's user avatar
  • 7,624
3 votes

Retrieve last time a file has been written to a folder (even though it isn't there anymore) in Ubuntu

The last modification time of a directory is updated whenever its contents change, so adding or removing a file in a directory can be seen even after the file is gone by looking at the directory’s ...
Stephen Kitt's user avatar
2 votes

What can cause “multiply claimed blocks” on an ext4 drive?

Multiply claimed blocks can occur with Network/Shared Storage, eg Fibre Channel, iscsi, SAN, JBOD devices etc. With these setups, if they are configured incorrectly, then two systems (Virtual or bare ...
Luke Attard's user avatar
2 votes
Accepted

Which filesystems support the C attribute?

chattr’s C attribute corresponds to the FS_NOCOW_FL flag in the kernel UAPI (defined in linux/fs.h). So the only file systems which support this attribute are those which handle that flag: currently, ...
Stephen Kitt's user avatar
2 votes
Accepted

How are block devices physically addressed in a file system

Do the pointers that are part of the inodes comprise of logical block indices or actual physical addresses? Logical, relative to beginning of the block device that contains the filesystem. then ...
telcoM's user avatar
  • 94.5k
2 votes

Retrieve last time a file has been written to a folder (even though it isn't there anymore) in Ubuntu

That would be a job for the inotify system interface, which you can use to subscribe to changes in a directory. With pyinotify and others there are useful scripting frontends for it. If you can't be ...
sina bala's user avatar
  • 299
2 votes

What could be the source of drastically different disk usage reports between df, lsblk and baobab?

Thanks to @frostschutz' comment and link to a related question, the problem could be further diagnosed using a bind mount: mkdir /mnt/root mount --bind / /mnt/root Upon inspection of the filesystem ...
kuadrat's user avatar
  • 51
1 vote
Accepted

What's limiting the depth of a recursive symlink chain?

When you do cd haha/haha/..., or really use any path symlinks, the kernel has to resolve the links to figure out where the path points to. In Linux, there's a limit to how many links it resolves ...
ilkkachu's user avatar
  • 137k
1 vote
Accepted

Each file gets one inode block

It's hard to know what they're thinking exactly (you'd have to ask them), especially since they talk about "all data on the FS" (not just one file), and mention "using inodes" (in ...
ilkkachu's user avatar
  • 137k
1 vote

What is the best place for storing of semi-short-lived data produced by a bash script?

I would do this in two parts: The core bash script, which makes a new uniquely named temp directory (under a suitable parent) for every run. A cleanup script (likely invoked by the core bash script ...
arp's user avatar
  • 141
1 vote

What is the most high-performance Linux filesystem for storing a lot of small files (HDD, not SSD)?

I would use the default FileSystem on your OS, but don't store data within files, and switch to use a SQlite3 database. https://sqlite.org/fasterthanfs.html It would be much faster for your use case, ...
Arnaud Bouchez's user avatar

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