пластмассовые, с регулируемой высотой накладки

# df /
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/lvm-slot10--0
2.0G 2.0G 0 100% /

# du -akx / | sort -rn | fgrep /dev/null | head -15
1029308 /dev/null.22874
165220 /dev/null.18565
115264 /dev/null.8357
100336 /dev/null.724
71028 /dev/null.23410
59840 /dev/null.1703
50672 /dev/null.3605
37016 /dev/null.32292
27320 /dev/null.397
2544 /dev/null.28946
1396 /dev/null.16699
0 /dev/null

# file /dev/null.[0-9]*
/dev/null.16699: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style,
from '/usr/sbin/slurmdbd'
/dev/null.1703: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style,
from '/usr/sbin/slurmctld'
/dev/null.18565: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style,
from '/usr/sbin/slurmctld'
/dev/null.23410: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style,
from '/usr/sbin/slurmctld'
/dev/null.28946: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style,
from '/usr/sbin/slurmdbd'