You grabbed Big.Linux.ISO.part1.rar from a forum, double-clicked it, and your archiver threw something like "Cannot find volume Big.Linux.ISO.part2.rar". Nothing extracted. The file is 500 MB, so it clearly contains something — why won't it open?
Because a rar part1 part2 set is not a group of independent archives. It is one archive that has been sliced into equal chunks, and the slices only make sense together. This guide shows you how the naming schemes work, how to verify you have the complete set before wasting time, and three concrete ways to extract it: unar, 7-Zip, and a browser-based route if you can't install software.
What a multi-volume RAR actually is
When someone compresses a 4.7 GB file, they often tell WinRAR to split the output into fixed-size volumes — 100 MB, 200 MB, 500 MB are typical. The compressed data stream is written continuously and simply cut at each size boundary.
That means a single part is a raw slice of a stream, not a standalone file. Part 1 holds the archive header and the file list. Part 7 holds bytes somewhere in the middle of a video file, with no header, no index, and no way to know where a file starts or ends. This is why:
- You always start extraction from part 1. Opening part 5 directly gives an error or a truncated mess.
- Every part must be present, in the same folder, with its original filename.
- One corrupt part breaks the whole output, not just its own share of the data.
The good news: the parts are sequential, so if a download manager gave you 9 of 10 files, you only need to re-fetch the missing one — not the entire 4.7 GB.
The two naming schemes you will see
Scene releases and forum uploads use two different conventions, and knowing which one you have tells you immediately which file to open.
New style (RAR 3.0 and later) — numbered .partN.rar names:
release.part1.rar 200,000,000 bytes
release.part2.rar 200,000,000 bytes
release.part3.rar 200,000,000 bytes
release.part4.rar 47,382,912 bytesStart from release.part1.rar. Large sets use zero padding — part01, part02 … part15 — so they sort correctly in a file manager.
Old style (RAR 2.x) — one .rar plus .r00, .r01, .r02:
release.rar
release.r00
release.r01
release.r02Here release.rar is the first volume and .r00 is the second. Open the .rar file, never the .r00. The counter runs .r00 to .r99, then continues .s00, .s01 for very large sets.
A third thing that looks similar but isn't: files named movie.mkv.001, movie.mkv.002. Those are plain byte-splits made by tools like HJSplit or 7-Zip's "split to volumes", not RAR volumes. 7-Zip handles them if you open the .001 file; on macOS or Linux you can also run cat movie.mkv.* > movie.mkv.
Check the set before you extract
Thirty seconds of checking beats a failed 20-minute extraction. Two things matter: no gaps in the numbering, and equal file sizes.
ls -l *.part*.rarEvery volume except the last should be byte-identical in size. If part6.rar is 83 MB while its siblings are 200 MB, that download was interrupted — redownload that single part. If the list jumps from part4 to part6, you are missing a volume and no tool on earth can rebuild it from the others.
Many release folders also ship an .sfv file containing CRC32 checksums for each volume. If you have one, verify it — it pinpoints exactly which part is damaged.
Extract a rar part1 part2 set with unar
unar (from The Unarchiver project) is the most forgiving command-line extractor around: it handles both naming schemes, finds the follow-on volumes automatically, and doesn't care about RAR version quirks.
Install it:
# macOS
brew install unar
# Debian / Ubuntu
sudo apt install unarList the contents first, without extracting — this also proves the chain is complete:
lsar release.part1.rarThen extract into a clean output folder:
unar -o ~/Downloads/release-out release.part1.rarUseful flags: -p yourpassword for encrypted sets, -f to overwrite existing files, and -D to dump everything into the output folder without creating an enclosing directory. Point the command at part1 only — unar pulls in part2, part3 and the rest by itself.
The 7-Zip route on Windows
7-Zip reads multi-volume RAR fine (it can't create them, but extraction is all you need). In Explorer, right-click the first volume → 7-Zip → Extract Here. From a terminal:
"C:\Program Files\7-Zip\7z.exe" l D:\dl\release.part1.rar
"C:\Program Files\7-Zip\7z.exe" x D:\dl\release.part1.rar -oD:\dl\outl lists, x extracts with full paths, -o sets the destination (no space after -o). Add -p for passwords. The same syntax works with 7z on Linux and macOS.
No installer? Convert the set in your browser
On a locked-down work laptop, a Chromebook or a phone, installing WinRAR isn't an option. The practical workaround is to turn the RAR set into a single ZIP, because ZIP opens natively in Windows Explorer, macOS Finder, Android and iOS Files.
Put every volume in one folder, then use our RAR to ZIP converter and add the whole set — starting with release.part1.rar. The rule from the desktop still applies online: the complete chain must be there, or the conversion fails with the same missing-volume complaint. What comes back is one ordinary .zip you can open anywhere without extra software.
If you also deal with 7z, TAR or GZ files, the rest of the archive converter tools work the same way.
Errors and what they really mean
- "Cannot find volume release.part3.rar" — that volume is missing, misnamed, or sitting in a different folder. Download it again; don't re-fetch the whole set.
- "Unexpected end of archive" — the last part is truncated. Compare its size against the uploader's listing.
- "CRC failed in file.mkv" — the data arrived, but one part is corrupt. Checksum the volumes, redownload the bad one, extract again.
- You renamed the files — stripping
part1/part2or changing the base name breaks the chain. Restore the original names exactly, including zero padding. - Everything is inside a nested `.rar` — some releases wrap a second archive inside. Extract once, then extract the result.
- Password prompt — multi-volume sets are often encrypted with the forum or site password. Check the release notes or
.nfofile.
One myth worth killing: there is no repair tool that reconstructs a missing volume. Recovery records (.rev files, if the uploader made them) can rebuild a damaged or missing part — but only if enough .rev files shipped with the release.
Your three-step routine for any split RAR
- Verify the set.
ls -lthe folder. Sequential numbering, identical sizes except the last file. - Open part 1 only.
unar release.part1.raror7z x release.part1.rar. Never point your tool at part 2 or at a.r00. - No tools available? Drop the full set into the RAR to ZIP converter and download one ZIP that opens everywhere.
Once the extracted file plays or mounts correctly, you can delete the volumes — they are just packaging. Keep them only if you plan to re-seed.
FAQ
Can I extract a multi-part RAR if one volume is missing? Not completely. Some tools will recover the files that happen to sit entirely inside the volumes you do have, but anything spanning the gap is lost. For a single large file split across all parts, you get nothing usable.
Which file do I open — part1 or the one without a number?
In the .partN.rar scheme, open part1. In the old scheme, open the plain .rar (the .r00 is the second volume, not the first).
Do I need WinRAR specifically?
No. unar, 7-Zip, PeaZip and The Unarchiver all extract multi-volume RAR for free. WinRAR is only required if you want to create new RAR volumes.
Why is part1 the same size as part2 if the content differs? Volumes are cut at a fixed byte size, not at file boundaries. Only the final volume is smaller, because it holds whatever remains.
Can I join split RAR files back into one .rar?
Merging volumes with cat or copy /b does not work for true RAR volumes — each one has its own header. Extract the contents instead, or convert the set to a single ZIP.
Is it safe to delete the parts after extracting? Yes, once you've confirmed the extracted file opens correctly. Verify first, delete second.