diff --git a/app/vmbackup/README.md b/app/vmbackup/README.md
index ca63572a7..f1c8635bb 100644
--- a/app/vmbackup/README.md
+++ b/app/vmbackup/README.md
@@ -219,6 +219,12 @@ See [this article](https://medium.com/@valyala/speeding-up-backups-for-big-time-
      Username for HTTP Basic Auth. The authentication is disabled if empty. See also -httpAuth.password
   -httpListenAddr string
      TCP address for exporting metrics at /metrics page (default ":8420")
+  -internStringCacheExpireDuration duration
+     The expiry duration for caches for interned strings. See https://en.wikipedia.org/wiki/String_interning . See also -internStringMaxLen and -internStringDisableCache (default 6m0s)
+  -internStringDisableCache
+     Whether to disable caches for interned strings. This may reduce memory usage at the cost of higher CPU usage. See https://en.wikipedia.org/wiki/String_interning . See also -internStringCacheExpireDuration and -internStringMaxLen
+  -internStringMaxLen int
+     The maximum length for strings to intern. Lower limit may save memory at the cost of higher CPU usage. See https://en.wikipedia.org/wiki/String_interning . See also -internStringDisableCache and -internStringCacheExpireDuration (default 500)
   -loggerDisableTimestamps
      Whether to disable writing timestamps in logs
   -loggerErrorsPerSecondLimit int
@@ -257,8 +263,15 @@ See [this article](https://medium.com/@valyala/speeding-up-backups-for-big-time-
   -pushmetrics.url array
      Optional URL to push metrics exposed at /metrics page. See https://docs.victoriametrics.com/#push-metrics . By default, metrics exposed at /metrics page aren't pushed to any remote storage
      Supports an array of values separated by comma or specified via multiple flags.
+  -s2a_enable_appengine_dialer
+     If true, opportunistically use AppEngine-specific dialer to call S2A.
+  -s2a_timeout duration
+     Timeout enforced on the connection to the S2A service for handshake. (default 3s)
   -s3ForcePathStyle
      Prefixing endpoint with bucket name when set false, true by default. (default true)
+  -s3StorageClass string
+     The Storage Class applied to objects uploaded to AWS S3. Supported values are: GLACIER, DEEP_ARCHIVE, GLACIER_IR, INTELLIGENT_TIERING, ONEZONE_IA, OUTPOSTS, REDUCED_REDUNDANCY, STANDARD, STANDARD_IA.
+     See https://docs.aws.amazon.com/AmazonS3/latest/userguide/storage-class-intro.html/
   -snapshot.createURL string
      VictoriaMetrics create snapshot url. When this is given a snapshot will automatically be created during backup. Example: http://victoriametrics:8428/snapshot/create . There is no need in setting -snapshotName if -snapshot.createURL is set
   -snapshot.deleteURL string
diff --git a/docs/vmbackup.md b/docs/vmbackup.md
index bbbaabd37..80930fc53 100644
--- a/docs/vmbackup.md
+++ b/docs/vmbackup.md
@@ -230,6 +230,12 @@ See [this article](https://medium.com/@valyala/speeding-up-backups-for-big-time-
      Username for HTTP Basic Auth. The authentication is disabled if empty. See also -httpAuth.password
   -httpListenAddr string
      TCP address for exporting metrics at /metrics page (default ":8420")
+  -internStringCacheExpireDuration duration
+     The expiry duration for caches for interned strings. See https://en.wikipedia.org/wiki/String_interning . See also -internStringMaxLen and -internStringDisableCache (default 6m0s)
+  -internStringDisableCache
+     Whether to disable caches for interned strings. This may reduce memory usage at the cost of higher CPU usage. See https://en.wikipedia.org/wiki/String_interning . See also -internStringCacheExpireDuration and -internStringMaxLen
+  -internStringMaxLen int
+     The maximum length for strings to intern. Lower limit may save memory at the cost of higher CPU usage. See https://en.wikipedia.org/wiki/String_interning . See also -internStringDisableCache and -internStringCacheExpireDuration (default 500)
   -loggerDisableTimestamps
      Whether to disable writing timestamps in logs
   -loggerErrorsPerSecondLimit int
@@ -268,8 +274,15 @@ See [this article](https://medium.com/@valyala/speeding-up-backups-for-big-time-
   -pushmetrics.url array
      Optional URL to push metrics exposed at /metrics page. See https://docs.victoriametrics.com/#push-metrics . By default, metrics exposed at /metrics page aren't pushed to any remote storage
      Supports an array of values separated by comma or specified via multiple flags.
+  -s2a_enable_appengine_dialer
+     If true, opportunistically use AppEngine-specific dialer to call S2A.
+  -s2a_timeout duration
+     Timeout enforced on the connection to the S2A service for handshake. (default 3s)
   -s3ForcePathStyle
      Prefixing endpoint with bucket name when set false, true by default. (default true)
+  -s3StorageClass string
+     The Storage Class applied to objects uploaded to AWS S3. Supported values are: GLACIER, DEEP_ARCHIVE, GLACIER_IR, INTELLIGENT_TIERING, ONEZONE_IA, OUTPOSTS, REDUCED_REDUNDANCY, STANDARD, STANDARD_IA.
+     See https://docs.aws.amazon.com/AmazonS3/latest/userguide/storage-class-intro.html/
   -snapshot.createURL string
      VictoriaMetrics create snapshot url. When this is given a snapshot will automatically be created during backup. Example: http://victoriametrics:8428/snapshot/create . There is no need in setting -snapshotName if -snapshot.createURL is set
   -snapshot.deleteURL string