Average writes to Disk

johnpoz

@fireodo what ssd are you using? Modern SSD even with 20GB a day you should still be like a 10 year lifespan..

I just looked up a shit $20 128GB ssd from lexar the ns100, and it lists 60TB write life.. at 20GB a day your still looking at 8 some years..

Off the cuff 20GB a day does seem like a lot... But even at that you should get decent life out of the SSD..

fireodo

@johnpoz said in Average writes to Disk:

what ssd are you using?

See my signature :-)

I already ordered some spare for ... just in case ;-)

johnpoz

@fireodo I don't see anything listed for 16GB size.. But the 64 is listed as

36.5TBW (64GB)

So you have to assume lower than that.. So yeah, prob not the best drives for lots of writes..

Lets call it half that.. Your looking at like 2.5 years only..

fireodo

@johnpoz said in Average writes to Disk:

@fireodo I don't see anything listed for 16GB size.. But the 64 is listed as

36.5TBW (64GB)

So you have to assume lower than that.. So yeah, prob not the best drives for lots of writes..

Lets call it half that.. Your looking at like 2.5 years only..

Of course this all sounds reasonable but for me its strange that a older APU (that I have as quick replacement in case of hardware failure - i do much HomeOffice) with 2.4.5 shows insignificant writes to disk (also ZFS) far far away from 20GB/day.

AndyRH

Extra space will get longer life, more room for TRIM to work with and at todays prices it is worth the investment IMHO.

fireodo

@andyrh said in Average writes to Disk:

Extra space will get longer life, more room for TRIM to work with and at todays prices it is worth the investment IMHO.

I understand that all very well - its the Researcher in me that wants to find out what the real cause of all that is! Eliminating the symptoms dont eliminate the ill (if it is one) ;-)

AndyRH

@fireodo said in Average writes to Disk:

its the Researcher in me that wants to find out what the real cause of all that is!

Agreed.
Not everyone does that. I like to know how it works too.

fireodo

@johnpoz Is this process telling you (or somebody else) something?

zpool-zroot{txg_thread_enter}

This process is doing very much writing when I use
top -SH -o write (and after that "m")

johnpoz

I see that pop up every few seconds on mine as well

But I have no idea what it is or does to be honest..

Maybe a zfs guru will chime in - that sure isn't me ;)

fireodo

@johnpoz said in Average writes to Disk:

But I have no idea what it is or does to be honest..

I googled about it but I did not find anything concludent - that's why I was asking.

Would you show me your output of iostat -d 5 6 ?

johnpoz

here you go - but I don't have a ssd, this is on a netgate sg4860

fireodo

@johnpoz said in Average writes to Disk:

here you go - but I don't have a ssd, this is on a netgate sg4860

Thanks a lot - your values are similar to mine! You have also ZFS?

johnpoz

Yeah zfs.. Like I said I agree that 20GB a day seems like a lot - if your doing your math right, etc. But even at that your typical ssd should have a long life anyway..

My desktop model sg4860 has eMMC not ssd.. Which also have limited life writes..

fireodo

@johnpoz said in Average writes to Disk:

My desktop model sg4860 has eMMC not ssd.. Which also have limited life writes..

Is that eMMC replaceable?

johnpoz

I don't think so - not easy... But I think there is something missing here on what is actually being written.

So from my understanding zpool iostat shows total since boot..

[21.05.1-RELEASE][admin@sg4860.local.lan]/: zpool iostat
               capacity     operations    bandwidth
pool        alloc   free   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
zroot        969M  25.1G      0     10    645   227K
[21.05.1-RELEASE][admin@sg4860.local.lan]/:

My box has been up for days.. Since I updated it to 21.05.1

Uptime 6 Days 02 Hours 12 Minutes 47 Seconds

edit: Well that can not be since boot... Not exactly sure what that reads to be honest.. But if you have it report every 2 seconds.

[21.05.1-RELEASE][admin@sg4860.local.lan]/: zpool iostat zroot 2
               capacity     operations    bandwidth
pool        alloc   free   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
zroot        970M  25.1G      0     10    645   227K
zroot        970M  25.1G      0      0      0      0
zroot        968M  25.1G      0     34      0   552K
zroot        968M  25.1G      0      0      0      0
zroot        967M  25.1G      0     35      0   624K
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0     38      0   532K
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0     33      0   602K
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0     34      0   520K
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0     33      0   618K
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0     33      0   531K
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0     33      0   621K
zroot        967M  25.1G      0      0      0      0
zroot        967M  25.1G      0      7      0   114K
zroot        967M  25.1G      0     24      0   415K
zroot        967M  25.1G      0      0      0      0

fireodo

@johnpoz Here is my output - I'm also no ZFS expert!
As far as I see not much different ...
zpool iostat
capacity operations bandwidth
pool alloc free read write read write

zroot 808M 11.7G 0 12 319 214K

zpool iostat zroot 2
capacity operations bandwidth
pool alloc free read write read write

zroot 807M 11.7G 0 12 319 214K
zroot 808M 11.7G 0 35 0 623K
zroot 808M 11.7G 0 30 0 432K
zroot 808M 11.7G 0 1 0 8.00K
zroot 808M 11.7G 0 0 0 0
zroot 807M 11.7G 0 36 0 535K
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 32 0 442K
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 2 0 28.0K
zroot 807M 11.7G 0 35 0 618K
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 32 0 420K
zroot 807M 11.7G 0 3 0 22.0K
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 35 0 486K
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 32 0 442K
zroot 807M 11.7G 0 0 0 7.99K
zroot 807M 11.7G 0 0 0 5.98K
zroot 807M 11.7G 0 32 0 442K
zroot 807M 11.7G 0 0 0 0
zroot 806M 11.7G 0 1 0 14.0K
zroot 806M 11.7G 0 2 0 28.0K
zroot 806M 11.7G 0 1 0 14.0K
zroot 807M 11.7G 0 33 0 442K
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 31 0 428K
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 0 0 0
zroot 807M 11.7G 0 10 0 623K
zroot 808M 11.7G 0 33 0 547K
zroot 808M 11.7G 0 35 0 498K
zroot 808M 11.7G 0 1 0 14.0K

mcury

SG-3100 - 21.05.1 - pfblockerng dnsbl python mode enabled

iostat -d 5 6

fireodo

@mcury I guess FS is UFS and not ZFS ...

mcury

@fireodo said in Average writes to Disk:

@mcury I guess FS is UFS and not ZFS ...

Indeed, UFS here, noatime in fstab

fireodo

@mcury said in Average writes to Disk:

@fireodo said in Average writes to Disk:

@mcury I guess FS is UFS and not ZFS ...

Indeed, UFS here, noatime in fstab

So it seams to cristallise that ZFS is the problem ...