нашел это в /var/log/apache/error.log
[Tue Aug 28 23:07:22.086803 2018] [core:warn] [pid 4642:tid 140536691099520] AH00098: pid file /var/run/apache2/apache2.pid overwritten -- Unclean shutdown of previous Apache run?
[Tue Aug 28 23:07:22.087430 2018] [mpm_event:notice] [pid 4642:tid 140536691099520] AH00489: Apache/2.4.18 (Ubuntu) configured -- resuming normal operations
[Tue Aug 28 23:07:22.087452 2018] [core:notice] [pid 4642:tid 140536691099520] AH00094: Command line: '/usr/sbin/apache2'
[Tue Aug 28 23:07:22.087933 2018] [mpm_event:alert] [pid 4647:tid 140536615016192] (11)Resource temporarily unavailable: apr_thread_create: unable to create worker thread
[Tue Aug 28 23:07:22.088191 2018] [mpm_event:alert] [pid 4646:tid 140536615016192] (11)Resource temporarily unavailable: apr_thread_create: unable to create worker thread
[Tue Aug 28 23:07:24.089398 2018] [mpm_event:alert] [pid 4642:tid 140536691099520] AH02324: A resource shortage or other unrecoverable failure was encountered before any child process initialized successfully... httpd is exiting!
[Tue Aug 28 23:07:50.494617 2018] [core:warn] [pid 4742:tid 139845939062656] AH00098: pid file /var/run/apache2/apache2.pid overwritten -- Unclean shutdown of previous Apache run?
[Tue Aug 28 23:07:50.495122 2018] [mpm_event:notice] [pid 4742:tid 139845939062656] AH00489: Apache/2.4.18 (Ubuntu) configured -- resuming normal operations
[Tue Aug 28 23:07:50.495138 2018] [core:notice] [pid 4742:tid 139845939062656] AH00094: Command line: '/usr/sbin/apache2'
[Tue Aug 28 23:07:50.495467 2018] [mpm_event:alert] [pid 4747:tid 139845862979328] (11)Resource temporarily unavailable: apr_thread_create: unable to create worker thread
[Tue Aug 28 23:07:50.495478 2018] [mpm_event:alert] [pid 4746:tid 139845862979328] (11)Resource temporarily unavailable: apr_thread_create: unable to create worker thread
[Tue Aug 28 23:07:52.496274 2018] [mpm_event:alert] [pid 4742:tid 139845939062656] AH02324: A resource shortage or other unrecoverable failure was encountered before any child process initialized successfully... httpd is exiting!
я пытаюсь удалить, очистить и удалить, затем переустановить apt-get install apache2 все еще получена та же ошибка, все установки и конфигурации по умолчанию
MemTotal: 262144 kB
MemFree: 226540 kB
Cached: 28040 kB
Buffers: 0 kB
Active: 58876 kB
Inactive: 47080 kB
Active(anon): 3392 kB
Inactive(anon): 8424 kB
Active(file): 55484 kB
Inactive(file): 38656 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 0 kB
Writeback: 0 kB
AnonPages: 11816 kB
Shmem: 2776 kB
Slab: 7564 kB
SReclaimable: 3520 kB
SUnreclaim: 4044 kB
Filesystem Size Used Avail Use% Mounted on
/dev/simfs 15G 732M 15G 5% /
devtmpfs 128M 0 128M 0% /dev
tmpfs 128M 0 128M 0% /dev/shm
tmpfs 128M 2.8M 126M 3% /run
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 128M 0 128M 0% /sys/fs/cgroup
none 128M 0 128M 0% /run/shm