diff --git a/server/filestore.go b/server/filestore.go
index 862897077a2..ec07a53d641 100644
--- a/server/filestore.go
+++ b/server/filestore.go
@@ -356,6 +356,9 @@ const (
 	// For smaller reuse buffers. Usually being generated during contention on the lead write buffer.
 	// E.g. mirrors/sources etc.
 	defaultSmallBlockSize = 1 * 1024 * 1024 // 1MB
+	// NOT an actual block size, but used for the sync.Pools, so that we don't allocate huge buffers
+	// unnecessarily until there are enough writes to justify it.
+	defaultTinyBlockSize = 1 * 1024 * 256 // 256KB
 	// Maximum size for the encrypted head block.
 	maximumEncryptedBlockSize = 2 * 1024 * 1024 // 2MB
 	// Default for KV based
@@ -947,6 +950,12 @@ func (fs *fileStore) writeStreamMeta() error {
 }
 
 // Pools to recycle the blocks to help with memory pressure.
+var blkPoolTiny = &sync.Pool{
+	New: func() any {
+		b := [defaultTinyBlockSize]byte{}
+		return &b
+	},
+}
 var blkPoolSmall = &sync.Pool{
 	New: func() any {
 		b := [defaultSmallBlockSize]byte{}
@@ -969,6 +978,8 @@ var blkPoolBig = &sync.Pool{
 // Get a new msg block based on sz estimate.
 func getMsgBlockBuf(sz int) (buf []byte) {
 	switch {
+	case sz <= defaultTinyBlockSize:
+		return blkPoolTiny.Get().(*[defaultTinyBlockSize]byte)[:0]
 	case sz <= defaultSmallBlockSize:
 		return blkPoolSmall.Get().(*[defaultSmallBlockSize]byte)[:0]
 	case sz <= defaultMediumBlockSize:
@@ -986,6 +997,9 @@ func getMsgBlockBuf(sz int) (buf []byte) {
 // Recycle the msg block.
 func recycleMsgBlockBuf(buf []byte) {
 	switch cap(buf) {
+	case defaultTinyBlockSize:
+		b := (*[defaultTinyBlockSize]byte)(buf[0:defaultTinyBlockSize])
+		blkPoolTiny.Put(b)
 	case defaultSmallBlockSize:
 		b := (*[defaultSmallBlockSize]byte)(buf[0:defaultSmallBlockSize])
 		blkPoolSmall.Put(b)
@@ -6237,6 +6251,17 @@ func (mb *msgBlock) writeMsgRecordLocked(rl, seq uint64, subj string, mhdr, msg
 	// reference. It will now stay strong until the flusher decides it is time to weaken.
 	mb.ecache.Strengthen()
 
+	// Make sure we have enough space to write into. If we don't then we can pull a buffer
+	// from the next pool size up to save us from reallocating in append() below.
+	if nsz := len(mb.cache.buf) + int(rl); cap(mb.cache.buf) < nsz {
+		prev := mb.cache.buf
+		mb.cache.buf = getMsgBlockBuf(nsz)
+		if prev != nil {
+			mb.cache.buf = mb.cache.buf[:copy(mb.cache.buf[:nsz], prev)]
+			recycleMsgBlockBuf(prev)
+		}
+	}
+
 	// Indexing
 	index := len(mb.cache.buf)