probing disks Post: 43963

8 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

how many disks do I have?

Hi How do I check how many disks do I have in Solaris & HP-UX? Also what does this mean c9t1d5 in /dev/dsk what is c, t, d etc cheers

2. Filesystems, Disks and Memory

Hello, I'm running Red Hat Linux on a Dell Poweredge 2650 Rack Server and wondered if anyone knew of a tool or command I could use to probe the memory slots on the motherboard. I know the machine has six memory slots and currently contains 1GB RAM, what I don't know however, is if it contains...

3. UNIX for Dummies Questions & Answers

Disks on AIX

Hello I've been working on AIX 5.3 ML3 on IBM pSeries520. That server has 6 HDD drives in 3 volume groups (1+mirror in each group). I must check which phisical disk is which disk in the system. For ex. I want to know that disk in 4th slot in the machine is marked as hdisk5 on AIX. Does anybody...

4. Solaris

probe-scsi-all hangs probing D1000

Hi folks, I�m having a problem with a Ultra60 box with diff scsi pci card conected to one D1000. The conection are correct because a checked the D1000 guide. When a do probe-scsi-all in the OBP, the D1000 blink all disks one time then the led of one of the disks powers off and then nothing...

5. AIX

SCSI Disks

Hi Is it possible to install in p5 and pSeries SCSI Disks from SUN on DELL? Will they work? Regards, Pit

6. Solaris

Disks compatibility

Hi all, I am trying to isntall veritas replicator on 2 DA 3000 storage , But with little luck . I am running a solaris 10 and vsf 4.1, Veritas Volume Replicator Option 4.1 My question is that : when i got the array i had 2 disks missing , So we had to replace them , but I found out that...

7. Solaris

Re-using disks

I would like to know if I can move the disks from a V240 chassis into a V440 chassis to use the increased resources (CPU & Memory) to boost performance. I know you can move disks between V210/240 chassis's, but I'm not sure if this would work between 240s & 440s. Any help would be much appreciated.

8. Solaris

host cannot see FC disks

Have a V440 server which we need to connect up to a SE6140. Did the zoning on the 3900 brocade silkworm and did mapping from the array to the host manually host initiator did not autodetect the wwn and had to key in manually. probe-scsi-all cannot show the fc disks. What is the problem here?

LEARN ABOUT CENTOS

systemd-readahead-collect.service

SYSTEMD-READAHEAD-REPLAY.SERVICE(8)			 systemd-readahead-replay.service		       SYSTEMD-READAHEAD-REPLAY.SERVICE(8)

NAME

       systemd-readahead-replay.service, systemd-readahead-collect.service, systemd-readahead-done.service, systemd-readahead-done.timer, systemd-
       readahead - Disk read ahead logic

SYNOPSIS

       systemd-readahead-replay.service

       systemd-readahead-collect.service

       systemd-readahead-done.service

       systemd-readahead-done.timer

       /usr/lib/systemd/systemd-readahead/systemd-readahead [OPTIONS...] COMMAND [DIRECTORY | FILE]

DESCRIPTION

       systemd-readahead-collect.service is a service that collects disk usage patterns at boot time.  systemd-readahead-replay.service is a
       service that replays this access data collected at the subsequent boot. Since disks tend to be magnitudes slower than RAM, this is intended
       to improve boot speeds by pre-loading early at boot all data on disk that is known to be read for the complete boot process.

       systemd-readahead-done.service is executed a short while after boot completed and signals systemd-readahead-collect.service to end data
       collection. On this signal, this service will then sort the collected disk accesses and store information about them in /.readahead.

       Normally, both systemd-readahead-collect.service and systemd-readahead-replay.service are activated at boot so that access patterns from
       the preceding boot are replayed and new data collected for the subsequent boot. However, on read-only media where the collected data cannot
       be stored, it might be a good idea to disable systemd-readahead-collect.service.

       On rotating media, when replaying disk accesses at early boot, systemd-readahead-replay.service will order read requests by their location
       on disk. On non-rotating media, they will be ordered by their original access timestamp. If the file system supports it,
       systemd-readahead-collect.service will also defragment and rearrange files on disk to optimize subsequent boot times.

OPTIONS

       systemd-readahead understands the following options:

       -h, --help
	   Prints a short help text and exits.

       --max-files=
	   Maximum number of files to read ahead. Only valid for thes collect command.

       --file-size-max=
	   Maximum size of files in bytes to read ahead. Only valid for the collect and replay commands.

       --timeout=
	   Maximum time in microseconds to spend collecting data. Only valid for the collect command.

COMMANDS

       The following commands are understood by systemd-readahead:

       collect [DIRECTORY]
	   Collect read-ahead data on early boot. When terminating, it will write out a pack file to the indicated directory containing the
	   read-ahead data.

       replay [DIRECTORY]
	   Perform read-ahead on the specified directory tree.

       analyze [FILE]
	   Dumps the content of the read-ahead pack file to the terminal. For each file, the output lists approximately how much will be read
	   ahead by the replay command.

SEE ALSO

       systemd(1)

systemd 208												       SYSTEMD-READAHEAD-REPLAY.SERVICE(8)