# After upgrading from 7.x to 8.x, Elasticsearch cannot start **URL:** \ **Category:** Elasticsearch\ **Created:** [August 30, 2024, 9:07pm UTC](https://discuss.elastic.co/t/after-upgrading-from-7-x-to-8-x-elasticsearch-cannot-start/365842 "2024-08-30T21:07:00Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![roman-tasi](https://avatars.discourse-cdn.com/v4/letter/r/7ea924/32.png) [@roman-tasi](https://discuss.elastic.co/u/roman-tasi)\ **Post date:** [August 30, 2024, 9:07pm UTC](https://discuss.elastic.co/t/after-upgrading-from-7-x-to-8-x-elasticsearch-cannot-start/365842/1 "2024-08-30T21:07:00Z")
These are the errors in the logs: `Aug 29 13:45:34 ELK-Stack.uhtasi.local systemd-entrypoint[13266]: Error occurred during initialization of boot layer` `Aug 29 13:45:34 ELK-Stack.uhtasi.local systemd-entrypoint[13266]: java.lang.module.ResolutionException: Modules tools and jdk.jdi export package com.sun.jdi to module HdrHistogram` `Aug 29 13:45:35 ELK-Stack.uhtasi.local systemd-entrypoint[13266]: ERROR: Elasticsearch died while starting up, with exit code 1` Help is appreciated! ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [September 2, 2024, 5:23am UTC](https://discuss.elastic.co/t/after-upgrading-from-7-x-to-8-x-elasticsearch-cannot-start/365842/2 "2024-09-02T05:23:03Z")
You have not provided a lot of information, so there is not a lot to go on. Did you follow [the official upgrade guide available in the documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-upgrade.html)? Also please share any errors and context around these from the Elasticsearch logs. ---
**Author:** ![roman-tasi](https://avatars.discourse-cdn.com/v4/letter/r/7ea924/32.png) [@roman-tasi](https://discuss.elastic.co/u/roman-tasi)\ **Post date:** [September 4, 2024, 12:32am UTC](https://discuss.elastic.co/t/after-upgrading-from-7-x-to-8-x-elasticsearch-cannot-start/365842/3 "2024-09-04T00:32:40Z")
I just reverted back to pre-upgrade. **This is my current Upgrade Assistant:** ![upgrade](https://us1.discourse-cdn.com/elastic/original/3X/f/c/fc46aa5e07c9691e979d5e1270347814d7ed1fc1.jpeg) I am bypassing the "Back up your data" since I am snapshotting the virtual machine on the VMware side anyway, if that's fine. My question: **Is the rolling upgrade required?** Or can I just do the RPM method without doing the rolling upgrade? ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [September 4, 2024, 8:47am UTC](https://discuss.elastic.co/t/after-upgrading-from-7-x-to-8-x-elasticsearch-cannot-start/365842/4 "2024-09-04T08:47:55Z")
> [@roman-tasi](#): > > I am bypassing the "Back up your data" since I am snapshotting the virtual machine on the VMware side anyway, if that's fine. That is not a supported backup method, so there is no guarantee that will work. Please see [the official documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/snapshot-restore.html#other-backup-methods) for further details. > [@roman-tasi](#): > > My question: **Is the rolling upgrade required?** Or can I just do the RPM method without doing the rolling upgrade? How many nodes do you have in the cluster? ---
**Author:** ![roman-tasi](https://avatars.discourse-cdn.com/v4/letter/r/7ea924/32.png) [@roman-tasi](https://discuss.elastic.co/u/roman-tasi)\ **Post date:** [September 4, 2024, 7:13pm UTC](https://discuss.elastic.co/t/after-upgrading-from-7-x-to-8-x-elasticsearch-cannot-start/365842/5 "2024-09-04T19:13:11Z")
> How many nodes do you have in the cluster? `"number_of_nodes" : 1` What are the next steps? ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [September 4, 2024, 8:27pm UTC](https://discuss.elastic.co/t/after-upgrading-from-7-x-to-8-x-elasticsearch-cannot-start/365842/6 "2024-09-04T20:27:41Z")
If you only have one node you can ignore the instructions around rolling upgrade. You will need to upgrade in place with downtime.