--- name: "zpios" section: "1" platform: "linux" package: "zfs-test" version: "0.7.12-2+deb10u2" release: "Debian 10 (Buster)" platforms: ["linux"] url: "https://new.carta.tech/zpios" --- # zpios(1) Directly test the DMU. ## NAME zpios - Directly test the DMU. ## SYNOPSIS **zpios \[options\] \<-p** *pool***\>** ## DESCRIPTION This utility runs in-kernel DMU performance and stress tests that do not depend on the ZFS Posix Layer ("ZPL"). ## OPTIONS **-t** *regex***, --threadcount** *regex* - Start this many threads for each test series, specified as a comma delimited regular expression. (eg: "-t 1,2,3") - This option is mutually exclusive with the **threadcount\_\*** options. **-l** *regex\_low***, --threadcount\_low** *regex\_low* **-h** *regex\_high***, --threadcount\_high** *regex\_high* **-e** *regex\_incr***, --threadcount\_incr** *regex\_incr* - Start *regex\_low* threads for the first test, add *regex\_incr* threads for each subsequent test, and start *regex\_high* threads for the last test. - These three options must be specified together and are mutually exclusive with the **threadcount** option. **-n** *regex***, --regioncount** *regex* - Create this many regions for each test series, specified as a comma delimited regular expression. (eg: "-n 512,4096,65536") - This option is mutually exclusive with the **regioncount\_\*** options. **-i** *regex\_low***, --regioncount\_low** *regex\_low* **-j** *regex\_high***, --regioncount\_high** *regex\_high* **-k** *regex\_incr***, --regioncount\_incr** *regex\_incr* - Create *regex\_low* regions for the first test, add *regex\_incr* regions for each subsequent test, and create *regex\_high* regions for the last test. - These three options must be specified together and are mutually exclusive with the **regioncount** option. **-o** *size***, --offset** *size* - Create regions at *size* offset for each test series, specified as a comma delimited regular expression with an optional unit suffix. (eg: "-o 4M" means four megabytes.) - This option is mutually exclusive with the **offset\_\*** options. **-m** *size\_low***, --offset\_low** *size\_low* **-q** *size\_high***, --offset\_high** *size\_high* **-r** *size\_incr***, --offset\_incr** *size\_incr* - Create a region at *size\_low* offset for the first test, add *size\_incr* to the offset for each subsequent test, and create a region at *size\_high* offset for the last test. - These three options must be specified together and are mutually exclusive with the **offset** option. **-c** *size***, --chunksize** *size* - Use *size* chunks for each test, specified as a comma delimited regular expression with an optional unit suffix. (eg: "-c 1M" means one megabyte.) The chunk size must be at least the region size. - This option is mutually exclusive with the **chunksize\_\* options.** **-a** *size\_low***, --chunksize\_low** *size\_low* **-b** *size\_high***, --chunksize\_high** *size\_high* **-g** *size\_incr***, --chunksize\_incr** *size\_incr* - **Use a** *size\_low* chunk size for the first test, add *size\_incr* to the chunk size for each subsequent test, and use a *size\_high* chunk size for the last test. - These three options must be specified together and are mutually exclusive with the **chunksize** option. **-s** *size***, --regionsize** *size* - Use *size* regions for each test, specified as a comma delimited regular expression with an optional unit suffix. (eg: "-s 1M" means one megabyte.) - This option is mutually exclusive with the **regionsize\_\* options.** **-A** *size\_low***, --regionsize\_low** *size\_low* **-B** *size\_high***, --regionsize\_high** *size\_high* **-C** *size\_incr***, --regionsize\_incr** *size\_incr* - **Use a** *size\_low* region size for the first test, add *size\_incr* to the region size for each subsequent test, and use a *size\_high* region size for the last test. - These three options must be specified together and are mutually exclusive with the **regionsize** option. **-S** *size \| sizes***, --blocksize** *size \| sizes* - Use *size* ZFS blocks for each test, specified as a comma delimited regular expression with an optional unit suffix. (eg: "-S 1M" means one megabyte.) The supported range is powers of two from 128K through 16M. A range of blocks can be tested as follows: "-S 128K,256K,512K,1M". - **-L** *dmu\_flags***, --load** *dmu\_flags* - Specify *dmuio* for regular DMU\_IO, *ssf* for single shared file access, or *fpp* for per thread access. Use commas to delimit multiple flags. (eg: "-L dmuio,ssf") **-p** *name***, --pool** *name* - The pool name, which is mandatory. **-M** *test***, --name** *test* - An arbitrary string that appears in the program output. **-x, --cleanup** - Enable the DMU\_REMOVE flag. **-P** *command***, --prerun** *command* - Invoke *command* from the kernel before running the test. Shell expansion is not performed and the environment is set to HOME=/; TERM=linux; PATH=/sbin:/usr/sbin:/bin:/usr/bin. **-R** *command***, --postrun** *command* - Invoke *command* from the kernel after running the test. Shell expansion is not performed and the environment is set to HOME=/; TERM=linux; PATH=/sbin:/usr/sbin:/bin:/usr/bin. **-G** *directory***, --log** *directory* - Put logging output in this directory. **-I** *size***, --regionnoise** *size* - Randomly vary the **regionsize** parameter for each test modulo *size* bytes. **-N** *size***, --chunknoise** *size* - Randomly vary the **chunksize** parameter for each test modulo *size* bytes. **-T** *time***, --threaddelay** *time* - Randomly vary the execution time for each test modulo *time* kernel jiffies. **-V****, --verify** - Enable the DMU\_VERIFY flag for trivial data verification. **-z****, --zerocopy** - Enable the DMU\_READ\_ZC and DMU\_WRITE\_ZC flags, which are currently unimplemented for Linux. - **-O****, --nowait** - Enable the DMU\_WRITE\_NOWAIT flag. **-f****, --noprefetch** - Enable the DMU\_READ\_NOPF flag. **-H****, --human-readable** - Print PASS and FAIL results explicitly and put unit suffixes on large numbers. **-v****, --verbose** - Increase output verbosity. **-?** **, --help** - Print the usage message. ## AUTHORS The original zpios implementation was created by Cluster File Systems Inc and adapted to ZFS on Linux by Brian Behlendorf \. This man page was written by Darik Horn \. ## SEE ALSO [**zpool**(8)](/zpool/8.md), [**zfs**(8)](/zfs/8.md)