# Companies using ext4

We found 465 companies that use ext4. 352 of them name it in their own job posts, and the rest through employees' public profiles. 317 job posts named it from October 2025 to August 2026. It comes up most in Administrator job posts.

Data as of November 9, 2026. Source: Sumble.

## Which companies name ext4 in the most job posts?

Apple and DDN have the most job posts naming ext4, with 43 and 37. BAE Systems has named it in job posts the longest of the five companies in the table, since April 2023.

| Company | Job posts | Recent job post |
|---|---:|---|
| [Apple](https://sumble.com/orgs/apple) | 43 | "Good understanding of block, object, and file storage solutions in Linux (such as LVM, XFS,ext4, S3, Ceph, Gluster, NFS)." (Storage Platform Engineer (SRE), Sep 7, 2026) |
| [DDN](https://sumble.com/orgs/ddn-storage) | 37 | "Configure and maintain storage and filesystems including ext4, xfs, LVM, NFS, iSCSI, and potentially Lustre." (on-prem devops engineer, Dec 4, 2025) |
| [DXC Technology](https://sumble.com/orgs/dxc-technology) | 35 | "Configure and maintain LVM, filesystems (ext4, XFS, OCFS2), multipath, and iSCSI storage at the OS layer." (OCI Server OS Administrator, Oct 23, 2026) |
| [BAE Systems](https://sumble.com/orgs/bae-systems) | 31 | "Multi-vendor filesystems such as XFS, GPFS, and CXFS, EXT4, CIFS, NFSClustered Blade systems and associated interconnects…" (Senior High Performance Computing (HPC) Systems Administrator, Feb 10, 2026) |
| [Oracle](https://sumble.com/orgs/oracle) | 27 | "Filesystem diagnosis and troubleshooting (ext4, btrfs, xfs, ocfs2 etc.)" (Senior Technical Support Engineer, Apr 23, 2025) |

## Is hiring for ext4 growing?

Job posts mentioning ext4 went from 0.19 to 0.15 in every 10,000 job posts, comparing March to May with June to August 2026. These are small numbers of job posts, so a few companies can move them.

| Month | Job posts naming it | All job posts | Per 10,000 job posts |
|---|---:|---:|---:|
| Oct 2025 | 16 | 1,413,673 | 0.11 |
| Nov 2025 | 36 | 1,822,119 | 0.20 |
| Dec 2025 | 27 | 1,236,103 | 0.22 |
| Jan 2026 | 27 | 1,828,002 | 0.15 |
| Feb 2026 | 27 | 1,856,647 | 0.15 |
| Mar 2026 | 34 | 1,850,711 | 0.18 |
| Apr 2026 | 33 | 1,728,886 | 0.19 |
| May 2026 | 34 | 1,821,509 | 0.19 |
| Jun 2026 | 32 | 1,909,496 | 0.17 |
| Jul 2026 | 25 | 1,815,180 | 0.14 |
| Aug 2026 | 26 | 1,835,698 | 0.14 |

## How many companies named ext4 in a job post for the first time in recent months?

ext4 showed up in job posts at 26 companies for the first time from June to August 2026, and 33 in the three months before. That brings the companies naming it for the first time since October 2025 to 92, through August 2026.

| Period | Companies naming it in a job post for the first time |
|---|---:|
| March to May 2026 | 33 |
| June to August 2026 | 26 |
| October 2025 to August 2026 | 92 |

Companies whose first job post naming it appeared in that period. Recruiters, staffing firms and job boards are left out.

## How do we know which companies use ext4?

352 of the 465 companies name ext4 in their own job posts. 113 come from employees' profiles alone.

| How we know | Companies | Share |
|---|---:|---:|
| Job posts name ext4 | 352 | 76% |
| Employees' profiles list ext4 | 113 | 24% |

## What size are the companies that use ext4?

34% of ext4 users are companies with 50 to 999 employees, and companies with more than 5,000 employees make up 31%, a high share for a tech page. 81 of its companies have fewer than 50 employees.

| Size | Share | Typical tech page |
|---|---:|---:|
| Under 50 employees | 17% | 22% |
| 50 to 999 | 34% | 38% |
| 1,000 to 5,000 | 18% | 17% |
| Over 5,000 | 31% | 23% |

## Where are ext4 companies based?

India is 1.7 times as common among ext4 companies as on the typical tech page, at 12%. The United States leads overall with 49%. Germany is less common than usual, at 2.9% against 4.4% on the typical tech page.

| Country | Companies | Share | Typical tech page |
|---|---:|---:|---:|
| United States | 219 | 49% | 43% |
| India | 52 | 12% | 6.9% |
| France | 23 | 5.2% | 4.6% |
| Brazil | 15 | 3.4% | 2.8% |
| Canada | 13 | 2.9% | 3.6% |
| Germany | 13 | 2.9% | 4.4% |

## Which teams work with ext4?

IT teams are by far the most common home for ext4, at 6 companies. Storage and systems administration teams come next, at 3 companies each.

| Team | Companies |
|---|---:|
| IT | 6 |
| Storage | 3 |
| Systems administration | 3 |
| DevOps | 2 |
| Engineering | 2 |
| Ge vernova advanced research | 2 |

## Which roles mention ext4 most?

Administrator and Data Center Engineer roles account for 21% of the job posts that name ext4. Administrator posts naming it numbered 12 from March to May 2026 and 8 from June to August.

| Role | Share | Oct 2025 to Aug 2026 | Mar to May 2026 | Jun to Aug 2026 |
|---|---:|---:|---:|---:|
| Administrator | 12% | 37 | 12 | 8 |
| Data Center Engineer | 9.1% | 29 | 10 | 3 |
| Customer Engineer | 8.5% | 27 | 10 | 6 |
| Software Engineer | 7.9% | 25 | 8 | 5 |
| Systems Engineer | 6.9% | 22 | 5 | 6 |
| IT Support | 5% | 16 | 3 | 5 |

## Which companies started naming ext4 in job posts recently?

Between April and August 2026, ext4 appeared for the first time in job posts at 33 companies: 13 commercial, 7 mid-market and 13 enterprise. Qube Cinema has the most job posts of the new commercial companies, 5 from April to August.

| Group | Company | Job posts, April to August 2026 |
|---|---|---:|
| Commercial | [Qube Cinema](https://sumble.com/orgs/qube-cinema) | 5 |
| Commercial | [Eximietas Design](https://sumble.com/orgs/eximietas-design) | 2 |
| Commercial | [indurad](https://sumble.com/orgs/indurad) | 2 |
| Commercial | [Scaleway](https://sumble.com/orgs/scaleway) | 1 |
| Commercial | [Backblaze](https://sumble.com/orgs/backblaze) | 1 |
| Mid-market | [Corebridge Financial](https://sumble.com/orgs/corebridge-financial) | 2 |
| Mid-market | [Commvault](https://sumble.com/orgs/commvault) | 2 |
| Mid-market | [Hyve Solutions](https://sumble.com/orgs/hyve-solutions) | 2 |
| Mid-market | [Argonne National Laboratory](https://sumble.com/orgs/argonne-national-laboratory) | 1 |
| Mid-market | [Onepoint](https://sumble.com/orgs/groupe-onepoint) | 1 |
| Enterprise | [Inetum](https://sumble.com/orgs/inetum) | 2 |
| Enterprise | [Groupe SII](https://sumble.com/orgs/groupe-sii) | 2 |
| Enterprise | [Systems Limited](https://sumble.com/orgs/systems) | 2 |
| Enterprise | [Capgemini](https://sumble.com/orgs/capgemini) | 1 |
| Enterprise | [Infosys](https://sumble.com/orgs/infosys) | 1 |

Companies that named ext4 in a job post for the first time between April and August 2026, ranked by their job posts in those months. AI-native companies get a group of their own, whatever their size. Recruiters and job boards are left out.

## What else do ext4 companies use?

ext3 and XFS are the tools most closely tied to ext4. Btrfs comes third, 600 times as common as usual, at 15%.

| Tool | Companies | Also name it | Typical | Times as common |
|---|---:|---:|---:|---:|
| ext3 | 23 | 13% | 0.02% | 759 times |
| XFS | 110 | 64% | 0.1% | 650 times |
| btrfs | 26 | 15% | 0.03% | 600 times |
| dnf | 10 | 5.8% | 0.04% | 156 times |
| Oracle ZFS | 56 | 33% | 0.27% | 121 times |
| RHEV | 12 | 7% | 0.08% | 83 times |
| SATA | 23 | 13% | 0.16% | 82 times |
| YUM | 22 | 13% | 0.17% | 76 times |

Shares are out of the 172 companies whose job posts name ext4, not counting firms whose job posts name almost every technology.

## Which project themes come up in ext4 job posts?

After broad digital transformation work, teams hiring for ext4 most often mention Cloud Cost Optimization, in 23 job posts. Broad digital transformation work shows up in 100 of its job posts.

| Project theme | Job posts |
|---|---:|
| Digital Transformation | 100 |
| Cloud Cost Optimization | 23 |
| Cloud Migration | 5 |
| Data Infrastructure Migration | 5 |

## About this data

Sumble built this page. Sumble gives sales, marketing and other GTM teams technographics and hiring signals for the companies they sell to: the technologies each company uses, which teams are hiring and for what, and who reports to whom. That helps a team know who to contact, why now, and what to say.

Sumble covers more than 3.6 million companies, 93 million job posts collected since 2022 and 194 million employee profiles, and tracks more than 37,000 technologies. It finds which technologies a company uses by reading its job posts and its employees' public profiles.

Sumble has a free plan, and the same data is available through its API and MCP server.

A company counts when its own job posts or its employees' public profiles name the technology. Hiring is that technology's share of all job posts collected each month. Quotes are copied word for word from the companies' job posts.

Every figure on this page comes from Sumble's own analysis, and you won't find it outside Sumble.