diff --git a/src/backup/fixed_index.rs b/src/backup/fixed_index.rs
index 1b58551a..ccea6485 100644
--- a/src/backup/fixed_index.rs
+++ b/src/backup/fixed_index.rs
@@ -1,4 +1,5 @@
 use failure::*;
+use std::io::{Seek, SeekFrom};
 
 use crate::tools;
 use super::IndexFile;
@@ -12,7 +13,9 @@ use std::path::{Path, PathBuf};
 use std::os::unix::io::AsRawFd;
 use uuid::Uuid;
 use chrono::{Local, TimeZone};
+
 use super::ChunkInfo;
+use super::read_chunk::*;
 
 /// Header format definition for fixed index files (`.fidx`)
 #[repr(C)]
@@ -68,6 +71,8 @@ impl FixedIndexReader {
             bail!("unable to get shared lock - {}", err);
         }
 
+        file.seek(SeekFrom::Start(0))?;
+
         let header_size = std::mem::size_of::<FixedIndexHeader>();
 
         // todo: use static assertion when available in rust
@@ -136,6 +141,38 @@ impl FixedIndexReader {
         Ok(())
     }
 
+    pub fn chunk_info(&self, pos: usize) -> Result<(u64, u64, [u8; 32]), Error> {
+
+        if pos >= self.index_length {
+            bail!("chunk index out of range");
+        }
+        let start = (pos * self.chunk_size) as u64;
+        let mut end = start + self.chunk_size as u64;
+
+        if end > self.size {
+            end = self.size;
+        }
+
+        let mut digest: [u8; 32] = unsafe { std::mem::uninitialized() };
+        unsafe { std::ptr::copy_nonoverlapping(self.index.add(pos*32), digest.as_mut_ptr(), 32); }
+
+        Ok((start, end, digest))
+    }
+
+    #[inline]
+    fn chunk_end(&self, pos: usize) -> u64 {
+        if pos >= self.index_length {
+            panic!("chunk index out of range");
+        }
+
+        let end = ((pos+1) * self.chunk_size) as u64;
+        if end > self.size {
+            self.size
+        } else {
+            end
+        }
+    }
+
     pub fn print_info(&self) {
         println!("Size: {}", self.size);
         println!("ChunkSize: {}", self.chunk_size);
@@ -284,10 +321,8 @@ impl FixedIndexWriter {
 
         self.unmap()?;
 
-        use std::io::Seek;
-
         let csum_offset = proxmox::tools::offsetof!(FixedIndexHeader, index_csum);
-        self.file.seek(std::io::SeekFrom::Start(csum_offset as u64))?;
+        self.file.seek(SeekFrom::Start(csum_offset as u64))?;
         self.file.write_all(&index_csum)?;
         self.file.flush()?;
 
@@ -367,3 +402,135 @@ impl FixedIndexWriter {
         Ok(())
     }
 }
+
+pub struct BufferedFixedReader<S> {
+    store: S,
+    index: FixedIndexReader,
+    archive_size: u64,
+    read_buffer: Vec<u8>,
+    buffered_chunk_idx: usize,
+    buffered_chunk_start: u64,
+    read_offset: u64,
+}
+
+impl <S: ReadChunk> BufferedFixedReader<S> {
+
+    pub fn new(index: FixedIndexReader, store: S) -> Self {
+
+        let archive_size = index.size;
+        Self {
+            store,
+            index: index,
+            archive_size: archive_size,
+            read_buffer: Vec::with_capacity(1024*1024),
+            buffered_chunk_idx: 0,
+            buffered_chunk_start: 0,
+            read_offset: 0,
+        }
+    }
+
+    pub fn archive_size(&self) -> u64 { self.archive_size }
+
+    fn buffer_chunk(&mut self, idx: usize) -> Result<(), Error> {
+
+        let index = &self.index;
+        let (start, end, digest) = index.chunk_info(idx)?;
+
+        // fixme: avoid copy
+
+        let data = self.store.read_chunk(&digest)?;
+
+        if (end - start) != data.len() as u64  {
+            bail!("read chunk with wrong size ({} != {}", (end - start), data.len());
+        }
+
+        self.read_buffer.clear();
+        self.read_buffer.extend_from_slice(&data);
+
+        self.buffered_chunk_idx = idx;
+
+        self.buffered_chunk_start = start as u64;
+        //println!("BUFFER {} {}",  self.buffered_chunk_start, end);
+        Ok(())
+    }
+}
+
+impl <S: ReadChunk> crate::tools::BufferedRead for BufferedFixedReader<S> {
+
+    fn buffered_read(&mut self, offset: u64) -> Result<&[u8], Error> {
+
+        if offset == self.archive_size { return Ok(&self.read_buffer[0..0]); }
+
+        let buffer_len = self.read_buffer.len();
+        let index = &self.index;
+
+        // optimization for sequential read
+        if buffer_len > 0 &&
+            ((self.buffered_chunk_idx + 1) < index.index_length) &&
+            (offset >= (self.buffered_chunk_start + (self.read_buffer.len() as u64)))
+        {
+            let next_idx = self.buffered_chunk_idx + 1;
+            let next_end = index.chunk_end(next_idx);
+            if offset < next_end {
+                self.buffer_chunk(next_idx)?;
+                let buffer_offset = (offset - self.buffered_chunk_start) as usize;
+                return Ok(&self.read_buffer[buffer_offset..]);
+            }
+        }
+
+        if (buffer_len == 0) ||
+            (offset < self.buffered_chunk_start) ||
+            (offset >= (self.buffered_chunk_start + (self.read_buffer.len() as u64)))
+        {
+            let idx = (offset / index.chunk_size as u64) as usize;
+            self.buffer_chunk(idx)?;
+         }
+
+        let buffer_offset = (offset - self.buffered_chunk_start) as usize;
+        Ok(&self.read_buffer[buffer_offset..])
+    }
+}
+
+impl <S: ReadChunk> std::io::Read for  BufferedFixedReader<S> {
+
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
+
+        use std::io::{Error, ErrorKind};
+        use crate::tools::BufferedRead;
+
+        let data = match self.buffered_read(self.read_offset) {
+            Ok(v) => v,
+            Err(err) => return Err(Error::new(ErrorKind::Other, err.to_string())),
+        };
+
+        let n = if data.len() > buf.len() { buf.len() } else { data.len() };
+
+        unsafe { std::ptr::copy_nonoverlapping(data.as_ptr(), buf.as_mut_ptr(), n); }
+
+        self.read_offset += n as u64;
+
+        return Ok(n);
+    }
+}
+
+impl <S: ReadChunk> Seek for  BufferedFixedReader<S> {
+
+    fn seek(&mut self, pos: SeekFrom) -> Result<u64, std::io::Error> {
+
+        let new_offset = match pos {
+            SeekFrom::Start(start_offset) =>  start_offset as i64,
+            SeekFrom::End(end_offset) => (self.archive_size as i64)+ end_offset,
+            SeekFrom::Current(offset) => (self.read_offset as i64) + offset,
+        };
+
+        use std::io::{Error, ErrorKind};
+        if (new_offset < 0) || (new_offset > (self.archive_size as i64)) {
+            return Err(Error::new(
+                ErrorKind::Other,
+                format!("seek is out of range {} ([0..{}])", new_offset, self.archive_size)));
+        }
+        self.read_offset = new_offset as u64;
+
+        Ok(self.read_offset)
+    }
+}
diff --git a/src/bin/proxmox-backup-client.rs b/src/bin/proxmox-backup-client.rs
index 6e316b1b..447bc108 100644
--- a/src/bin/proxmox-backup-client.rs
+++ b/src/bin/proxmox-backup-client.rs
@@ -626,11 +626,16 @@ fn restore(
         }
     };
 
-    if !archive_name.ends_with(".pxar") {
-        bail!("unknown file extensions - unable to restore '{}'", archive_name);
-    }
+    let server_archive_name = if archive_name.ends_with(".pxar") {
+        format!("{}.didx", archive_name)
+    } else if archive_name.ends_with(".img") {
+        format!("{}.fidx", archive_name)
+    } else {
+        bail!("unknown archive file extension (expected .pxar of .img)");
+    };
 
     let client = client.start_backup_reader(repo.store(), &backup_type, &backup_id, backup_time, true).wait()?;
+    let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config);
 
     use std::os::unix::fs::OpenOptionsExt;
 
@@ -640,23 +645,42 @@ fn restore(
         .custom_flags(libc::O_TMPFILE)
         .open("/tmp")?;
 
-    let tmpfile = client.download(&format!("{}.didx", archive_name), tmpfile).wait()?;
+    if server_archive_name.ends_with(".didx") {
+        let tmpfile = client.download(&server_archive_name, tmpfile).wait()?;
 
-    let index = DynamicIndexReader::new(tmpfile)?;
+        let index = DynamicIndexReader::new(tmpfile)
+            .map_err(|err| format_err!("unable to read dynamic index '{}' - {}", archive_name, err))?;
 
-    let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config);
+        let mut reader = BufferedDynamicReader::new(index, chunk_reader);
 
-    let mut reader = BufferedDynamicReader::new(index, chunk_reader);
+        let feature_flags = pxar::CA_FORMAT_DEFAULT;
+        let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags, |path| {
+            if verbose {
+                println!("{:?}", path);
+            }
+            Ok(())
+        });
 
-    let feature_flags = pxar::CA_FORMAT_DEFAULT;
-    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags, |path| {
-        if verbose {
-            println!("{:?}", path);
-        }
-        Ok(())
-    });
+        decoder.restore(Path::new(target))?;
 
-    decoder.restore(Path::new(target))?;
+    } else if server_archive_name.ends_with(".fidx") {
+        let tmpfile = client.download(&server_archive_name, tmpfile).wait()?;
+
+        let index = FixedIndexReader::new(tmpfile)
+            .map_err(|err| format_err!("unable to read fixed index '{}' - {}", archive_name, err))?;
+
+        let mut reader = BufferedFixedReader::new(index, chunk_reader);
+
+        let mut writer = std::fs::OpenOptions::new()
+            .write(true)
+            .create(true)
+            .create_new(true)
+            .open(target)
+            .map_err(|err| format_err!("unable to create target file {:?} - {}", target, err))?;
+
+        std::io::copy(&mut reader, &mut writer)
+            .map_err(|err| format_err!("unable to store data - {}", err))?;
+    }
 
     Ok(Value::Null)
 }